Note: Descriptions are shown in the official language in which they were submitted.
1055176
This invention relates to sound recording and reproducing machines
According to the invention there is provided a telephone answering
machine wherein incoming messages are recorded on an endless recording
medium, the machine comprising sound recording and reproducing means, means
for driving the recording medium along a predetermined path within which a
message is recorded on or reproduced from the medium by the recording and
reproducing means, means for detecting an incoming ringing current applied
to the machine via a telephone line, and control means adapted, each time a
ringing current is detected by the detecting means, first to actuate the
sound recording and reproducing means to reproduce a recorded answering
text, and subsequently to actuate the driving means and the sound recording
and reproducing means so that a message represented by an electrical signal
subsequently applied to the machine via the telephone line is recorded on
the recording medium, the control means being further adapted, when a
plurality of messages have been recorded on the medium and an electrical
command signal for reproducing the messages is applied to the machine and
without prior selection of a predetermined play back sequence by an oper-
ator, to actuate the driving means and the sound recording and reproducing
means so that the last message to be recorded is reproduced first
Preferably, the control means are adapted, when the electrical
command signal is applied to the machine, to actuate the sound recording
and reproducing means so that the messages are reproduced in the reverse
; order frDm the order in which they were recorded
Preferably, the telephone answering machine is intended for us in
recording messages on an endless recording medium in a series of tracks
which extend lengthwise of the medium at locations mutually spaced in a
direction laterally of the medium, wherein the sound recording and reproduc-
ing means comprise a sound recording and reproducing head for use in record-
ing the ~aid mes~ags~ on the recording medium, and mean~ for effecting
3~ ~elatiYe m~Ye~ent between t~le r~c~rding and rcproduc~ng hcad and the record-
ing medlum in a dlr~ctlon latsrally o~ the m4dium,
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l~S5176
Suitably, the control means actuate the sound recording and re-
producing means so that the message represented by each of the electrical
message signals is recorded on a respective one of the said tracks, the
said means for effecting relative movement causing a stepwise relative
movement between the recording and reproducing head and the recording medium
between the formation of adjacent tracks and between the reproduction from
adjacent tracks.
Suitably, the means for effecting relative movement comprise
ratchet and pawl means coupled to the first recording and reproducing head,
and means adapted, when each one of the electrical message signals is
received, to operate the ratchet and pawl means in a first sense, thereby
to cause relative movement in a predetermined direction between the record-
ing and reproducing head and the medium, and further adapted, when the
electrical command signal is applied to the machine, to operate the ratchet
and pawl means in a second sense, opposed to the first sense, thereby to
cause relative movement in the opposite direction to the predetermined
direction between the recording and reproducing head and the medium.
Preferably, the control means are adapted, when messages are being
reproduced from the said tracks in the reverse order, and a further, pre-
determined command signal is applied thereto to actuate the driving meansand the sound recording and reproducing means so that messages recorded on
one or more tracks already reproduced are again reproduced.
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1055176
The invention will now be described, by way of example, in
greater detail with reference to the accompanying drawings, iD which:
Figure 1 is a section of the tape used in a machine according to
the invention;
Figure 2 is a diagrammatic perspective view of part of a tape
deck in a machine according to the invention;
Figure 3 is a perspective view of a mechanism for effecting
movement of a sound recording and reproducing head in the machine of
Figure 2; and
Figure 4 is an electrical circuit in the machine of Figures 1
and 2.
The sound recording and reproducing machine shown in Figures 2,
3 and 4 of the drawings is a telephone answering machine for use with an
endless tape of the form shown in ~igure 1, this tape being one upon which
announcement texts and a series of fifteen incoming messages can be recorded,
Recorded messages can be played back in the reverse order by the owner of
the machine, either by operating controls provided on the machine or by
telephoning into the machine by dialling his own number from a remote
location.
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~055176
Referring to I~i~ure 1, an enales~ magnetic tape 1 for use
in the present machine i~ approximately sixty in¢hes long and
half an inch wide. The tape 1 is adapted to receive a series o~
1 sixteen tracks, tracks 1 to 16, of recorded information, the
5 tracks extending lenethwise of the tape in mutually spaced parallel
¦ relationship. One of the sixteen tracks, track 16, is reserved
for recording a telephone answering text made up of an opening
j text ~ and a closing text 5 and fifteen tracks, tracks 1 to 15,
¦ are available for recording incoming messages. There is one
j 10 blank track, track 0. Also provided on the tape is a trans~ersely
I extending metal strip 7 which is used to actuate the machine to
¦ perform a series of switching operations, as hereinafter described.
! Referring to Figure 2, the endless tape 1 i~ arranged in
the form Gf a loop which extends around a series of pillars 9
-I 15 upstanding from a tape de¢k il ln the machine. The tape 1 ls
¦ arranged so th~t ea¢h r~ecorded tra¢k is di~posed in a horlzontdl
plane. Eacb pillar 9 i5 coated with P.T.F.E., graphite or
¦ ~ilicore co~pound~ to reduce fri¢tion. For driving the tape 1
around the path deM ned by the pillars 9 a motor M ~shown in
F$gure 4) is provided below the tape deck ll. The motor M is
coupled to a flywheel at the lower end of a shaft (not sho~m)
~ which extends upwardly through an aperture in the deck 11 and
;j has a capstan (not shown) mounted at its upper end. In use, tape
1 ls engaged between the capstan and a pinch roller and, upon
energisation of the motor M, ls driven along the path.
As~ociated ~ith the metal strip 7 on the tape 1, and,
in¢luded in the ele¢tri¢al control circuit of Figure 4, four
pair~ of electrlcal ¢orltact~, Ao Aoo, Co Coo, Po Poo. All four
~ilr~ of contact~ are ~hown dlagrammatl¢ally ln P~gure 1 and
¢ont~ct~ Ao and Aoo are ~hown ln ~l~ure 2. Reerrlng to ~izure 2,
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~055176
each of the contacts is formed by a rod 1 which is upstanding
from a printed circuit board 15 forminæ part of the control
, circuit and mounted below the tape deck 11. Each rod 1 extends
¦ upwardly through an aperture in the tape deck 11 and con~acts
one surface of the tape 1. A pressure pad 17 maintains the tape
in engagement with an associated pair of contacts. Each pair
~ of contacts is short circuited by the metal strip 7 once during
! - each movement of the tape along the path.
~ Contacts Ao Aoo are arranged ad~,acent to the beginning
! lo of the tape path i e ad~acent to the beginning of opening text
! 3 when the machine is not in use. Assuming that the tape
i takes ~0 seconds for a complete traverse of the path, contact,s
! Bo Booa~edisposed approximately 5 seconds from the snd of thc
path and they are followed immediately by contacts Po Poo and
then contacts Co Coo.
I F~r reccrdlng the announcement text on the tape 1 a
¦ fixed recording head AH, shown in Flgure 4, ls mounted on the
7I tape deck 11 at a vertlcal locatlon adJacent to the uppermost
I recordlng tra¢k, track 16, on the tape. For reproduclng
! 20 tnformatlon recorded on trad~s 1 to 15 a movable head M~, shown
I ln ~igures 3 and 4, is provided.
! Referrin8 to Figure 3, the head MH is moved upwardly and
do~nwardly to positlons ad~a¢ent respective tracks 1 to 15 by
operatlon o~ a stepplng motor M8, whlch ls mounted on a chassis
belou the tape deck 11. The motor M~ is arranged so that a
~wlt~hlng dl~c 19 ~e¢ured to an output shaft thereof ls dlsposed
ln a vertl¢al Dlane, Extendlng ~arallesl wlth the motor ~haft 18
~ a 3wltchlng ~ha~t 21 u~on whlch a 3erle~ of 3wlt¢hlng cams 23 1
J mou~ted. A~oelated wlth ~ach cam 2 1~ a leaf contact ~wltch,
~ ~0 a# her~lna~t~r de~¢rlbe~,
.,
_ ~ _
.
lOSS17~ -
! At the end of the ~wltchine shaft 21 remote Prom the motor
¦ MS there is a pinion 25 which engages a rack 27 se¢ured to a rod
1, 29 supporting the head MH. Secured to the opposite end of the
j switching shaft 21 are two ratchet wheels 31 and ~3, respectively,
3 5 the wheels being arranged with each tooth on the wheel 31 inclined
in a clockwise sense relative to a radial line through the tooth
and each tooth on the wheel ~ inclined in an anticlockwise
direction, as viewed from the end of the shaft remote from the
¦ lead MH. A first pawl ~5 is located above the ratchet wheel ~1
¦ 10 and a second pawl 37 below the other wheel ~, the pawls ~5 and
~7 being secured to respective horizontally extending arms ~9
i ' and 41. The end of each arm 39, 41 remote fro,m the associated
¦ pawl ~5, ~7 is ~ivotally connected to the switching disc 19 on
the shaft of motor M~J connection between the disc a~.~ t'ne Ch'O
arms being effected at, respective locations on th~ disc which
are diametrical,ly opposed. Each pawl 35, 37 is constraine~ f
¦ movernent ln a generall,y horlzontal dlrection by engagsmen+, of-a
I pln cn the a~soclated arm ~9, 41 in a slot formed ln an asscciatsd
¦ stationary guide 43, 45. A tension spring 47 c~nnects together
¦ 20 the two arms ~9 and 41 at a location on each arm interrnediate
the associated pawl ~5 or ~7 and the pivot for the arrn. The
switching disc 19 is maintained at an angular position wherein
j each pawl ~5 and ~7 is disengaged from the associated ratchet
¦ wheel 31 or 3~ by means of a spring 49 which extends between the
di~c and the chassis and urges the disc into a dead-centre position.
e arrangement of the swit¢hing disc 19, arrns ~9 and
! 41, pawl~ 35 and ~7 and ratchet wheels 31 and ~ ls such that
rotation of the gwltchlng di~c ln a flrst sense moves the pawl
~ 3f~ lnto 0ngagern~nt wlth the a~soclated ratchet wheel ~1, thereby
i 30 rotatin~ the wh~el 31 ar~ the ~wlt¢hlng ~hai~t 21 throu~h a
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1055176
predetermined ~mall angle ln a fir~,t sense. Eneagement between
the rack 27 and pinion 25 at the oppo~ite end of the ~witching
shaft 21 lead~ to a predetermined upwards moveMent of the head
MH by an amount sufficient to move the head from a vertical
location adJacent one recording track on the tape 1 to a location
adjacent to the track immediately above. Rotation of the s~itching
disc 19 in the reverse sense causes the other pawl ~7 to engage
the associated ratchet wheel ~3. This rotates the switching
shaft 21 through a small angle in the opposite sense, thereby
to cause movement of the head MH downwardly from one recording
track to the track immediately below.
To allow for manual movement of the movable head MH each
pawl 35 and 3'1 is disengaged from the associated ratchet whecl
- 31 or 33 when thc motor MS is not energised. For effect ngmanual movement a control knob 51 on the front of ~he machine
18 couplcd via a pulley 53 and a rubber band 55 to a second
pulley 57 which is fiecured to the switching shaft 21. A v'sual
indlcatlon of the a~.gular pogltlon of the swltching ~haft 21 1~
provlded by an indicator wheel 59 secured to one end of the ~haft.
Further leaf contact switches 61 are provlded ad~a¢ent
to the ~witching disc 19, thesé further swit¢hes belng operated
by pegs on the switching disc.
The motor~ M and M3, the head AH and MH and the contacts
Ao Aoo, Co Coo, Po Poo and Bo Boo, referred to above, are
connected together in the electrical control circuit of Figure 4,
whlch is proviaed below the tape deck 11.
Referring to Flgure 4, the control clrcuit lnclude~ first
an lnput clrcult I whlch ~ervec to sen~e an lncomlng rlnging
current on a telephone llne Ll, L2 and, ln re~onse to such current
~0 cau~e~ power to be supplied to the remalnaer of the olr~ult.
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1055~76
Secondly, there is an amplifier circuit A for controlling the
supply of current to a recording amplifier RA and a playback
amplifier PA. Each of these amplifiers is shown twice in
Figure 4, in one case with po-~er supply lines connected thereto
and in the other case with signal input and output lines
connected. Thirdly, there is a remote control circuit RC which
can be operated by the owner of the machine dialling in from
a romote location. Finally, there are switching circuits 5 for
varying the electrical connections to motors M and MS and the
heads AH and MH.
The input circuit I of Figure 3 includes a bridge
rectii~ier MR which, in use, is connected to the line Ll L2 vla
capacltors Cl and C2. The output of the rectifier MR ls ~onnec,,ed
via a leaf ccntact switch 16, which is one of the ~wl~¢hes
mentioned above, to the gate of a silicon ¢ontrolled re¢tifier
5CRl. Rectifier SCRl and the wlnding of a relay R~,l are ¢onnected
in serles be~,ween the terminals of a battery (not ~ho;.n in
Flgure ~) and the j~nctlon between the rectifler and the winding
18 connected to earth potential via cont,acts Ao Aoo. Also
coupled to the gaté of rectlfler SCRl ls the collector electrode
of a translstor Tl.
The relay RLl has three groups of contacts a, b and c,
d, e and f, and g, h and i.
Contact~ a, b and c are u~ed for maklng and breaking
¢onnectlon between the battery and the clrcults A, RC and ~,
referred to above. Contact~ d, e and f are for connectlng one
ter~Lnal of a ~torage caDacltor C~ to the battery or to contact
Co, Contact~ g, h an~ rve to make and break connc¢tlon
b~t~an ~ ~rlmar~ wln~Ln~ of a llne tran~former Tn and the lLne
Ll L2. A ~¢or~ r~ ~ln~ln~ of tran~ormer TR 1~ conn~cted ~la
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lOS5176
resistor Rl to the input of receivin~ ampllfier RA and the olltpUt
of this amplifier is connected to the movine head MH. m e
secondary winding is also connectcd to the output of playback
amplifier PA.
A transistor T2 has its collector connected to the
~unction between contact d of relay RLl and contact Co and its
emitter connected to a negative supply line PS2 from the battery
thereby to provide a discharge path for capacitor C3. me base
of transistor T2 is connected via ao~pacitor C5 to the cathode
of a silicon controlled rectifier SCR~ in the remote control
circuit RC.
Contact Coo~ which is at the output of input circuit I,
is.connected to the gate of a second silicon controlled rectifier
SCR2 which is in the a~lifier circuit A. Rectifier SCR2 læ
¢onnected in series ~ith the re¢ordin~. amplifier RA between a
po~itive power supply line PSl, con~sc~ed to contact ~ of relay
R~l, and the negatlve ~upply llne PS2. From the anode of
rectlfler SCR2 a connection iæ made fir~t to the baæe of a
tranælstor T~, whlch is connected ln series with playback
ampllfler PA between lines PSl and P~2. The anode of rectlfier
8CR2 is also connected via a capacitorto contact Bo, which in
turn 1 connected via a resistor to the llne PSi. Contact Boo
læ ¢onnected to llne PS2, vla a parallel circult made up of a
capacitor C6 and a resiætor R2, ar~ to contact Poo. Finally,
there i~ a connection from the anode of rectlfler SCR2 to the
baæe of tranæiætor Tl in input clrcuit I,
In the rernote control clrcuit RC a tone detector clrcult
TD ha~ an inDut, ~ thereof c~r~lected to the ~econdary wlnding of
the llne tran~forrner TR ln the lnput clrc~lt I. An output 8 of
the d~tector ¢lr¢uit T~ 1~ cor~lected to the ba~e of ~ trar~ tor
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1055176
T4 which has its emitter connected directly to the llne PSl and
its collector connécted vla a resistor to the line PS2. The
collector of transistor T4 is also connected via a dlode Dl and
a capacitor C8 to the gate of rectifier SCR3, referred to above,
and via a further diode D2 to the base of a transistor T5.
A storage capacitor C4 is connected between base of transistor T5
and the line PS2.
In the switching circuit S a winding of a relay RL2 is
connected between the line PSl and the collector of a transistor
T6. The anode of the above-mentioned rectifier SCR3 is connected
to the emitter of transistor T6 and .the cathode of the rectifier
is connected to line PS2 via a resistor R3 and a leaf contact
switch 0, which is one of the switches referred to above. The
baæe of trans$~tor 6 is connected to a resistive netwcrk ~n t'ne
collector cir~uit of transistor T5 and the emitter of transistor
T6 is connected via a resistor R4 to line PSl and via a resi~tor
R5 to the base of translstor Tl in input circuit I. Contacts LP2
of a local playback swltch LP, hereinafter described, are connécted
betwee~ the winding of relay R~2 and leaf switch 0.
Relay ~L2 has three groups of contacts a, b and c, d,e
and f, h,i,~,k,l and m.
Contacts a,b and c are used for making connections between
contact Po, contact Coo and the base of a transistor T7 ln circuit
~, m e emltter of transistor T7 is connected to the base of a
transistor T8.
COQtact~ d,e and f are for connecting the lnput of the
~layback am~lifler PA to the movlng head MH or flxed head AH.
Conta¢ts h to m are for connecting the stepplng motor MS
an~ tran~l~tor T8 ln ~erle~ between the llne~ P,~l and P32.
~otor ~ e~nanently ¢onnect d b~tween llnes PBl and P32.
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1055176
In addition to the zwitches zho~n in Fi~ure ~ the ¢ontro]
circuit includes further switches which are used in lo¢al operation
of the machine, as hereinafter described.
In use, an opening text 3 and a closing text 5 are
recorded on track 16 of the tape 1, as hereinafter described ar~
- the tape is arranged with the metal strip 7 ~ust beyond thecontacts Ao Aoo and the beginning of the opening text ~ ~ust
before contacts Ao Aoo, as shown in Figure 1. The machine is
connected to the line Ll L2 in a "stand-by" mode i.e. ready to
receive an incoming message on the line. In the stand-by mode
the battery is cor~ected across relay RLl and rectifier SCRl
but there is only a small leakage current through the rectifier
and the relay is not energised. me contacts of relays RLl and
RL2 are in th~ condition shown in Figure ~. The sto~age capacl~o,
C~ is charged to the battery potential through the contacts e and
f of rela~ RLl. Since the conta¢ts a and b of relay RLl are OP~lJ,
no power iS s~plled to the ampllfiers RA and PA, the remote
control ¢ir¢ult RC~ or to the motors MS and M,
'~hen a ringing current iQ applied to the line Ll L2 as
a result of an ~utside call, current flows to the bridBe rectifier
MR through the capacitors Cl and C2. A d.¢. voltage ls then
developed at the output of the bridge MR and the voltage is
applied from the bridge to the gate of the rectifier SCRl.
Re¢tifier SCRl condu¢ts, relay ~Ll is energised and the contacts
of the relay are switched.
Thu~, conta¢ts h and i of the relay RLl are closed to
connect the primary winding of tran~forrner TR across the line
Ll L2, This provid~ a d,¢, path whi¢h ¢ompletez the loop to the
tele~hone ~x¢harlge, Canta¢t~ a and b of the relay RLl are alzo
clo~ed ~o that the battery 1~ conneeted to the ~ower zupply lines
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1055176
PSl and PS2. This means that the motor M i6 ener~ised to drive
the tape 1 around the loop. At this stage the rectifier SCR2
is cut off, since no voltage is applied to the gate. Althou~h
there is a small current through the recording amplifier RA,
via the resistors in the base circuit of 'ransistor T~, this is
insufficient for operation of the amplifier. This small current
is sufficient to apply a positive bias to the base of transistor
T3, however, and this transistor conducts. As a result current
flows through the playback amplifier PA, which is energised.
Finally, contacts d and e of the relay RLl aré closed and the
charge stored on capacitor C~ is applied to contact Co.
5ince the relay ~L2 is not energised the fixed head AH
is cor~ected to the in~ut of the pl~-hack amplifier PA via
contacts e and f of the relay. The ~atput to the playback
amplifier PA is connected to line v~a ~ransformer TR, Wlth the
motor M energised the machine operates to playback the openlng
arrnouncement text ~ re~orded on tra~k 16 of the tape 1 to ths 1 ne
Ll L2.
When the tape 1 has been run-rlng for approY.imately 25
seconds, the metal strip 7 on the tape short circuits the contacts
Bo and Boo for approximately l/lOth of a second. This has n~
effect on rectifier SC~2, which was already cut off, and the
recordlng amplifier RA remains lnoperative.
Immedlately after passlng contacts Bo and Boo the metal
strlp 7 hort clroults the contacts Po and Poo. However, &ince
the ¢ontact Po ls cor~ected to contact a of relay ~L2 ar~ slnce
the conta¢t a 1~ open-¢lrculted, thls ha no effect.
Ina~edlately ~ter passlng contact~ Po Poo the ~trlp 7
~h~rt ¢lr¢ults the contact~ C'o ar~ Coo. m 1~ ha~ the followln~
r~llt~, Plr~t, th~ o~paclt,~r C~ 1~ dl~ch~rg~a ~cro~ the ga~e
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1055176
of rectifier SCR2, via the contacts d and e of relay RLl and the
contacts Co and Coo, This switches on the rectifier SCR2 so
that current can flow between power the supply lines PSl and PS2
to energise the recording amplifier RA. Moreover, when the
rectifier SCR2 conducts the voltage applied to the bases of
transistors Tl and T~ becomes less positive. Transistor T~
is therefore cut off and the supply of current to the playback
amplifier PA is terminated. Transistor Tl conducts and a
positive voltage is applied to the gate of rectifier SCRl from
the emitter of transistor Tl.
Charge from the capacitor C~ also flows via the contacts
d and e of relay RLl, contacts Co and Coo, and contacts b and c
of relay RL2 to the base of transistor T7. m is causes the
.transistor T7 to condu~t and ~pply a positive voltage to the base
of the *ransi tor T8, switching on the translstor T8. Current
now n ows between the power suppJ.y lines P~,l and PS2 via transl~tor
T8 and contacts m and 1 of relay RL2, ~otor MS and conta~t,s i ~nd
of relay RL2. The motor M~ is energised and the swlt¢hlng di~c
ls rotated through a predeterrnined small angle, sufficient to
move the pawl 35 into engagement with the associated ratchet wheel
~, The switchlng shaft 21 also rotates through a small angle,
and the rack 27 engaging the pinion 25 at one end of the shaf't
ls ralsed by an amount suff'iclent to bring the movable head MH
lnto a posltion ad~acent track 1 on the tape 1.
~5 The machine i5 naw ln a ¢ondltion sultable for recordlng
'an lncanlng rnessage from the llne Ll L2, Thls message i8 applled
vla the llne transf'ormer TR and the reslstor Rl to the lnput of
the recordlng arnpllf'ler RA. From thc output of the ampllfler RA
the me~age 1~ ap~lled to the movsble head MH, whl¢h ls a
~0 canblned playback ar~ eraue head, ar~ iu th~reby re¢orded on
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- 1055176
track 1 of the tape.
m e tape 1 now makes one complete traverse of its path,
which takes approximately ~0 seconds. During this time the
incoming message is recorded on track 1. At the end of this
period, the metal strip 7 again reaches and short circuits
contacts Bo and Boo and causes rectifier SCR2 to be cut off.
This causes power to be removed from the recording amplifier RA
and supplied to playback amplifier PA. Additionally, a positive
bias is applied to the base of transistor Tl and this transistor
is cut off, thereby removing the positive bias on the gate of
rectifier SCRl.
When the metal strip 7 short circuits the contacts Po
and Poo there is no effect since these two contacts are disconnected
from the circuit. Wher. the ~trip 7 reaches contacts Co and Coo,
the rectifier SCR2 remains cut off and, since there is no charge
- on capacitor C~, the translstors ~( and T8 are not switched on
and the motor MS is not, energised.
81nce the fixed head AH remalnP connected to the input
of the playback amplifier PA via ¢onta¢ts e and f of relay RL2,
and since power is supplied to the playback amplifier PA, the
machine is now in a condition to play back the closing text 5 to
the llne. This occupies approximately 5 seconds.
After the closing text 5 has been transmitted, the metal
~trlp 7 on the tape 1 ~hort cir¢ults the contacts Ao and Aoo.
~his applles a short clrcuit a¢ross the re¢tifier SCRl, which is
cut off. Accordingly, when the tralling edge of the strip 7 has
moved beyond conta¢t Ao the relay RLl is de-energised. Contacts
h and i of relay RLl are opened, disaonnecting the transforMer
TR from the ~lne Ll L2. '~he contRcts a and b of the relay RLl
are o~aned, dl~¢onneatln~ the battery from the recording
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1055176
amplifier RA, the~ playback ampli~ier PA, the remote control
circuit RC and the motors M and MS. 'me inertia oP the motor
M ensures that the tape 1 is drlven to a position where the metal
strip 7 is disengaged from the contact Aoo,
As mentioned above, the owner of the present machine càn
arrange for messages recorded on trucks l to 15 to be played back
to him by telephoning his own n~nber from a remote locatlDn 'and
transmitting an audio signal of predetermined frequency over the
line from a portable transmitter. The playback operation is
effected in the following manner.
First, the incoming ringing current on the telephone line
Ll L2 causes the machine to operate and transmit the opening text
recorded on track 16, in the manner described above. W~ilst the
machine is transmitting the opening text, the o~mer transmits the
audio signal of predetermir.ed frequenc~ from 'nis tra~smltter. The
audio sl~al i~ applied vla the line transformer TR to an input
terminal 3 of the tone detector TD in tha remote control circu~t
RC. Thl3 causes the output 8 of the detector ~D to go low,
switching on the transistor T4 and c~sing lte collector electrode
to assur.s a positive potential.
m e positlve potentlaI at the collector of transistor T4
18 applied to the gate of the rectifier SCR3, causing the rectifier-
to conduct via resistor Rl. With rectifier SCR~'conducting, a
' negative going potential is applied from the anode of the rectifierto the base of transistor Tl, switching on the transistor and
¢au lng a positlve blas to be applled to the gate of rectifier
8CRl, Thls po~ltlve bla~ prevent~ rectlfler 8CRl from being 3witched
off untll rectl~ier gC~3 ha3 been turned of~ by the opening of
leaf contaets o, a~ hereafter de~¢rlbed, Wlth the re¢tiPler 8CR~
¢andu¢tln~ a Do~ltlve ~ e 1~ applled fr~n the c~thode Or the
1055176
rectifier via the capa¢itor C5 to the base of transi~tor T2
m e transistor 2 ¢onducts and the capacitor C3 is discharged.
m e positive potential at the collector of translstor T4
is also fed via the contacts band c of relay RL2 to the base of
transistor T7. This causes the transistor T7 to conduct and apply
a positive potential to the base of transistor T8, which also
conducts. With the transistor T8 conducting, current is supp~ied
from the power supply lines PSl and PS2 to the stepping motor MS
and the motor is energised. mis rotates the switching shaft 21
so that the movable head MH is raised to a vertical location
ad~acent to the track which is immediately above the track bearing
the last of the recorded messages.
m e pGS~tiVe potential at the ¢ollector of transistor T4
is also deve'opsd across the ¢apacitor C4 and applie~ to tho ba~e
f trans stor T5. Translstor T5 ¢ondu¢ts and gro~nds the base Or
translstor T6. This ¢uts ~ff the transistor T6 and prevents the
relay RL2 from being energised, even though the recti~ier 8CR~
is conducting.
The charge on capacitor C4 leaks away via the emitter-base
clr¢uit of transi~tor T5. When the capa¢itor C4 is dlscharged the --
translstor T5 i8 switched off and the transistor T6 ¢onducts.
The relay ~L2 ls therefore energised.
Ehergisation of the relay RL2 ¢auses ¢onta¢t e to be
conne¢ted to ¢onta¢t d, thus connecting the movable head MH to
~he lnput of the playback amplifier PA and disconne¢ting the fixRd
head AH from the playba¢k ampllfier. In additlon, the contact 1
of relay RL2 1~ dl~conne¢ted from contact J and ¢onnected to
¢on~a¢t h and the movable conta¢t i 1~ ~wltchea from contact m
to contact k. '~hla rever~e~ the ~olarlty of the ¢onnectlon~ to
#t~ln~ rnotor M~,
. - 17 -
~OS5176
The motor M ls still energized and the tape 1 continues
to be driven around the loop. Althou~h the playback amplifier
PA is still energised and the movable head MH i~ connected to
line Ll L2 via this amplifier, the head is adJacent to the track
above the last recorded message.
When the tape 1 has almost completed one traverse of the
loop the metal strip 7 short circuits contact Bo and Boo, mis
applies a short circuit across rectifier SCR2, which was already
turned off. In addition, capacitor C6 is connected between power
supply lines PSl and PS2 and is charged to the battery potential.
- As movement of the tape l continues the metal strip 7
connects together contacts Po and Poo. m e potential on
capacitor C6 is then applied via the contacts Po and Poo and the
contacts a ar~ ~, of relay RL2 to the base of transis~r T7.
Transistors T7 and T8 conduct and current flows between the
power ~pply lines PSl and PS2 through the transistor T8, the
¢ontacts h and i of relay R~2, the stepping motor MS and the
conta¢ts 1 and m of the relay. The motor M~ is energised ar~l the
movable head ~H is moved down to a location ad~acent the track
bearing the last recorded incoming message.
When the metal strip 7 reaches contacts Co and Coo there
ls no effect on rectifier SCR2, since capacitor C~ has already been
dlscharged via transistor T2, as described above. The playback
amplifier PA remains energized and the recording amplifier RA
remains cut oPf. m e machine is therefore in a condition such
that the last recorded messa~e i transmitted back to the owner
of the machine vla llne Ll L2 durlng the next movement of the tape
around the loo~.
Wh~n thl~ last recorded me~a~e ha~ be~n rclayed to the
~0 owner and t~le t,a~e 1 ha~ almo~t can~leted lt~ mov~ment arv~n4 the
1055176
loop, the metal strip 7 agaln sh~rt circuits contacts Bo and Boo.
m is connects the capacitor C6 across the batte~y and charges the
capacitor to the battery potential.
When the metal strip 7 short circuits contacts Po and Poo,
capacitor C6 is again discharged via contact Poo and Po and
contacts a and b of relay RLl, applying a positive pulse to the
transistor T7. Transistor T7 conducts and in turn switches on
the transistor T8. m e stepping motor MS is again energised and
the movable head MH is moved down to a position ad~acent to the
last-but-one recorded message. mis message is now transmitted
to the line Ll L2.
The above described sequence of operations is repeated
until the movable head MH has been stepped do~n to a posltion
ad~acent the blank track, track 0, whi¢h is the track below the
incar.in~ message first recorded. With the nead MH in this position,
the ~witching ~haft 21 is in an ang~lar position whereln the leaf
contact switch 0 is opened by the associated cam 2~ on the switch-
lng shaft. This turns off rectlfier SC~ and cause~ relay RL2
to be de-energised. The Motor M rem~lns energlsed and the
closln~ text 5 ls tran~mltted to the llne Ll L~ 1nce the fixed
head AH ls connected to the llne vla contacts e and f of relay
RL2 and the playback amplifier PA.
- When the rectifier SC~ i switched off, the gate bias
18 removed from the rectifier SCW since transistor Tl i al0
switched off. Accordingly, when the metal strip 7 short circuits
¢ontacts Ao and Aoo the rectlfier SC~l 13 turned off, the relay
RLl ls de-energised and the machlne has been returned to a
#tand-by condltion, ready to receive a further ~equence of
lncomdng eall~.
If the owner of the machlrle delay~ tr~n~mlttlng ~n audlo
g -
10551~76
signal until the openin~ text ~ ha~ been transmitted ~d the
machine is switched into a conditlon for receivin~ an incorning
messa~e, the sequence of operations descrlbed above is m~dlfied
in that transmission of the last recorded message is delayed until
the tape 1 has been driven twice along its path.
When the machine is playing back recorded messages in the
manner described above, the owner may wish to replay one or more
of the messages which he has already heard. This can be achieved
by operating the portable transmitter to transmit two or more
pulses of audio signal from thq remote location. The movable
head MH is then stepped upwards by a number of steps which is one
less than the number of pulses, in the following manner.
Assuming that the machine is in the playback mode, the
firr'c ~ulse of audio signal is applied to tha input ~ of the
tone detsctor TD and results in the output 8 ~olng low, as described
above~ This action switches on the transistor T4 so that the
collector electrode of the transls~or assumes a posl~lve potentlal,
as al~o descrlbed above.
The posltive potential at the collector of tran istor T4
i8 applled to the contact ¢ of relay ~L2, but sir,ce the relay is
energised, contact c is not connected to contact b and the
potential is not applied to transistor T7. Tbe positive potential
at the collector of transistor T4 is, however, applied to the
ba~e of transistor T5, which conducts and causes the transistor
T6 to be switched off. This de-energises the relay RL2, whereupon
tbe contacts assoclated wlth the relay are moved to the position
~ho~n in Yl~ure 2.
m e tlrne con~tant of the ¢apacltor C4 and the ba~e-emltter
elr~ult o~ tran~l~to~ T5 are sueh that tran~i~tor T5 cor~uct~, the
tran~l~t~r T6 r~naln~ ~ut o~f ar~ the relay RL2 r~nalrl~ ~e-ener~i~ed
,"
105517~
for a period of time ~ufficient for the remaining pulses of audio
signals to be received by the machine. Each time one of these
signals is reoeived a posltive potential is applied from the
collector electrodes of transistor T4 to the base of tran~istor
T7, via the contacts b and c of relay RL2. Transistors T7 and
T8 are therefore switched on each time a subsequent pulse of
audio signal is received, and for each pulse the stepping motor
MS is operated to raise the movable head MH from a position
ad~acent one track to a position ad3acent the track immediately
above.
- Cnce the movable head MH has been brought up to the
required track, the message on that track is played back to the
line Ll L2 in the manner described above.
If the owner t~ansmits ~ number of audio slgnals
sufflcient to cause the movable heed ;~H to be ralsed above track
16, a leaf contact switch 161 ls a¢tu~ted by the a~soc~ated cam
2~ on the swltchlng ~haPt 21, Leaf ¢onta¢t swlt¢h 16l (not
shown in Figure 4J ls ¢onnected in serie~ with the lead from the
~otor MS to the power supply line P~l. When the contact~ of leaf
swlt¢h 161 are opened, the motor MS ~ switched off and further
ùpwards movement is prevented.
As mentloned above, the present machlne lncludes further
- swit¢hés, not shown in Figure 2, for effe¢tlng local operatlon of the ma¢hine.
Thus, to enable the owner to playback recorded me~sages
the above-mentioned local playback swit¢h LP has a first pair of
¢onta¢t~ LPl ¢onne¢ted in parallel with the re¢tifler SCRl. When
the s~it¢h LP 18 operated these conta¢ts ¢lose and the gate of
~C~l b~eome~ pozltlv~, ~CRl lz turned on and relay ~Ll lz energlsed.
Poner lu then ~uDDlled to arnDllfler clr¢ult A ~nd to the motor
1055176
circuit M, as described abovc. Further contacts of the ~witch
LP (not shown) operate to disconnect the output of the playback
amplifier PA from the line Ll L2 and to connect the output to a
loudspeaker, not shown. Finally, the relay RL2 is energised by
the contacts LP2 of switch LP which short circuit rectifier
SCR~ and transistor T6.
The machine then perforrns the sarne sequence of operations
described above, the recorded messages being played back in the
reverse order to that in which they were recorded. When the
movable head MH reaches track O the leaf contact switch o opens
and relay RL2 is de-energised, thereby moving the connections to
motor MS to a condition whereln no further downwards movement of
the head MH can take place.
To record the opening and closing texts ~ and 5, respective'y,
a second switch L ~ is provided. Thi~ switch L ~ has contacts
(not shown) which operate to disccr~le~ the input of recording
amplifier M from the line tran~fortner '~R and to co~nect ~he input
to a mlcrophone, not ~hvwn. Further contacts of switch L~ 3erve
to di~connect the contacts Co and Cco from the answering circult
~0 and to connect ¢ontaet Co to contact Coo to contact Aoo.
Also provided is a start button, not shown, which, when
operated, causes poqitive potentials to be applled to the gates
of rectifiers SCRl and SCR2. Finally, there is a further switch
~hleh ls connected in parallel with transistor T6 and rectifier
~CR~ and which, when operated, cau~es relay RL2 to be energised.
With the~e ~witehe~ operated the tape 1 is driven along
the loop and the owner reeords the opening text ~ via the
~lero~hone. A vl~ual lndlcation i8 provided when the end of the
~erioa reservea for recordlng the openlns3 text ~ ha~ been reached.
34 The taDe then sto~s. 'rhe ~tart ~jutton 1~ th~n ~re~~ed agaln and
the ta~e 1 contlnufs~ to travers~e tho lD untll the metal 0trlp 7
dho~t eircsultts ¢ontaetss Co ar~ ~oo, when th~ rffla~ RLl 1~ de-energl~Qd
h~3 rnotoP ~ 1~ s~lt~3hea ~r. ~ 0~lt~o~ n~w pr~s~ th~ ~t~ n
_ ,~J~ _
10551'76
again and records the closing teY.t 5, When the metal strip 7
short circuit~ the contact~ Ao and Aoo the relay ~Ll is again
de-energised and motor M i8 switched off.
In a modification of above machine the stepping motor
MS which moves the movable head MH upwardly and downwardly is
connected in series with a silicon controlled rectifier and
the series circuit so formed is connected between the lines PSl
and PS2. Connected in~parallel with the series circuit is
a storage capacitor of ~000~ F. From the gate of the rectifier
a connection is made to a source from which a pulse is applied
to the rectifier each time the head MH has to be moved.
In use, the storage capacitor is charged to the battery
potential from the lines PSl and PS2. When a pulse is applied
to the gate of the rectifier the rectifier i3 rendered conductive
and oharge from the capacitor n ows throu~l ~he mGtOr MS and the
rectifier. The motor is theréfore operate~ to move the head MH
upwdrdl,~ or downwardly. Curr~nt flow through the motor MS cea~es
a~ ~oon as the voltage on the capacitor ha~ fallen below the value
ne¢essar,y to maintain conduction of the rectii'ier.
m is modifled clrcuit has the advantages that lt has a
self re-fietting actlon and that it avoids largé current surges
from the battery.
I,n a ~urther modification of the machine a device is
provided for detecting when the endlefis tape has been broken or
has be¢ome ~arnmed ln the machine. The devlce ls sensitive to
the level of direct current flowing in the playback amplifler PA
~hen an lncoming ringing ¢urrent has been recelved and the machine
ha~ been ~wlt¢hed to a condltlon for playlng back the openlng
announ¢ement text ~. If the d,¢. level 1~ low, lndi¢atlng that
the t~xt ~ 1~ not belng tran~mltted, the devi¢e generate~ pul~e~
~hi~h are a~lie~ to the ~te~ping motor M3, Ihe motor operate~ to
,,, - 2~ -
1055176
move the movable he~ M~l upwardly to a position ad~acent to
track 16 on the tape 1. This corresponds to the situation
where the tape is filled with recordlngs of in¢omlng me~sage~
and
further operation of the machine is inhibited
The machine can also be modified by using two
solenoids in place of motor MS.
In a further modification of the above machine,
one or more of the pairs of contacts Bo Boo, Po Poo and Co
Coo in the above machine is removed and the machine provided
with a tlmer. The latter is connected into the control circuit
in such manner that it is triggered by capacitor C3 when SCRl
is energised. Output pulses are provided by the timer at
predetermined intervals of time after triggering, these pulses
being applied 'GO ouher parts of the circuit so as to effect
correspondins swit¢hing operatlons to those performed by the
closing of contaots Bo Boo, Po Poo and Co Coo. For exa.~ple,
after 25 secGnds t~me uelay a pulse from the timer trlggers
rectlfler ~2
Althou~l the tape 1 used ln the above ma¢hine had
flfteen tracks ava'lable for recording lncomlng messages lt
wlll be appreclated that a greater or lesser nurnber may be
provided. Irrespe¢tive of the total number of tracks whlch are
provided the final tra¢k, track 15 ln the case of tape 1J above,
can bear a pre-recorded announcement to the effe¢t that all tracks
are full and that the caller should'phone back later. m ls a¢cou~cement
1~ played back to the llne each tlme an inooming rlnging current
18 received b~ the machine.
In a further machlne a¢cordlng to the lnventlon, the
recordlng rhe~lum 1~ a ~lngle taut band or tape provlded wlth meane
operatlve o~ each rotatlon of the ban4 to cau~e the band ~r an asso¢lated
- 2~ -
,"
,
1055176
recordln~ and reprodu~ing head to move in a lateral direction, acro~s
the width of the band, so that the head is aligned with a different
track on the band during different revolutions of the ba~d.
The tape itself may be physically modified to trigger
the movement, e.g. by means of one or more perforations in the
tape and/or notches in the edge of the tape. Alternatively or
in addition a separate triggering element may be attached to
the tape. The revolution of the tape may be sensed electrically,
magnetically, mechanically, or in any other convenient way to
provide the desired traversing movement before or after each
revolution of the tape.
- The use of a taut tape makes it possible for the
tape itself to bs used as a driving or trigger element for
initiating ths 'at~sral movement and the power for ef*ectln~ the
movement can oe obtained directly from power supplied by the tape
drive mechanism. Ihis can substantially simplify the opera~ion ær~
¢onstruction, and hence the co~t, of preparing the machine, compared
with known arranOer(,ent~.
In general, the tape will revolve but will not take
24 part in the traYersinO movement, which will be effe¢ted by means
of a mechanical selector which locates the sir~le recording and
reproducing head over the correct track of the tape. The band
or tape can effectively act as an escapement mechanism to initiate
the operation of the mechanical track selector using power obtained
dlre¢tly from the tape dr$ve mechani~m.
- On ea¢h rotation of the tape the head i~ dire¢tly
drlven acro~s the tra¢ks.
Ih~ ~arne head ¢an be u~ed both for replaying and
recordlng the next tra¢k and for replaying and recordlng the
mez~age track~, In thl~ ca~e, th~ ~elsctor mcchanl~m automatlcally
Dl~¢e~ the h¢a~ over the text tra¢k wh~n ~ tslo~hone call 1~ re¢~l~ed,
,,
- ~5 -
",,, "
1055176
for a ~irst rotation Or the tape band, and then moves the head to
a free message track. Alternatively, the head ls ¢onst,rained always
to track the text when a call is received, and the sele¢tor pre-
selects the track on which the messages are to be recorded but the
head is not permitted to move to that track until a~ter the flrst
"text" revolution.
A reversing mechanism is provided so that during
replaying of the messages the direction of traverse from track
to track is the reverse of that during recording; it is to be
understood that in general successive messages will be recorded
on adJacent tracks.
As already indicated, the drive from the tape to the
head may be a direct mechanical drlve, or an electromagnetic
drive may be used.
In place o~ the métal strip 7 a section of the tape 1
can be made condu¢tive. Alternatively, the metal strip 7 and the
assoclated ¢ontacts Ao, Aoo, ~o, Boo, Co, Coo, Po and Poo ¢an
be replaced by other swlt¢hln~ arran~ement~, For example, a ll~ht
source can be arranged to pro~ect a bea~ of light on to the tape
and a photosensltlve devl¢e arranged to detect a change ln the
lntenslty of llght transmltted by or reflected from the tape
each tlme a section of tape havlng dlfferer.t optlcal propertles
from the remalnder of the tape moves past a predetermlned lo¢atlon.
m e resultlng ¢harge ln ¢urrent through the devi¢e ls then used to
operate s~it¢hes ln the ele¢trl¢al ¢ontrol clrcult of the machlne.
Alternatlvely, a sectlon of the tape may be provlded with means
which actuate a magnetlc, electrlcal or me¢hani¢al senslng devlce
~hen they rea¢h the predetermined locatlon. A further machlne a¢cordlng
to the lnverltlon ha~ a ~tatlonery "multl-tra¢k" head ln pla¢e of
the rn4va~le head ~H ln the ma¢hlne de8¢rlbed abow. The multl-tr~ck head
1055176
is formed of siY~teen lndividual heads, each assocl~ted with a respective
one of the tracks on an endless tape. The individual heads are formed
as a single assembly which is mounted on the tape deck o~ the ma¢hine
with each head adjacent to the associ~ted track. Associated with
the multi-track head are switching circuit~ which ef~ect electri¢al
connections to respective heads so that incoming messages are re¢orded
on respective tracks in sequence.
Although a sound recording and a reproducing machine
according to the invention may be a telephone answering machine it
could also be some other machine in which a series of messages
or other items of information has to be recorded on a recording
medium and subsequently replayed.
,
,
3o
,, _ ~ _
105517~
SUPPLEMENTARY DISCLOSUR~
A further machine according to the invention will now be described
with reference to Figures 5A, B and C of the drawings. This machine is a
modification of the machine shown in Figures 1 to ~, having a simplified
mechanism for moving a recording and reproducing head laterally of a tape
and mechanically operated switches which allow a single amplifier A to be
used in place of amplifiers RA and PA.
Referring to Figure 5A, the present machine is designed for use with
an endless tape 101 having one track reserved for recording a telephone
answering text and fifteen tracks for recording incoming messages. The
answering text is made up of an opening text only. In place of the metal
strip 7 on the tape 1, two metal foils MPl and MF2 are provided on the tape
101. The foils MFl and MP2 are spaced lengthwise of the tape 101 and
associated with respective pairs of electrical contacts la, lb and 2a, 2b.
In the present machine a fixed head (not shown) is again provided
for use in recording and reproducing the answering text. A movable head H
is provided for recording and reproducing incoming messages.
Referring to Figure 5B, the head H is secured to one end of a
generally horizontal plate 103 and the other end of the plate is mounted on
a wall upstanding from the tape deck of the machine by means of a plate 105
of spring steel. The head H is disposed adjacent to the tape 101 and is
movable upwardly and downwardly (as hereinafter described) to positions
adjacent to respective tracks on the tape. In each position of the head H
the tape 101 is engaged between the head and a felt pad 107 which is mounted
on a self centering bracket 109.
To enable the head H to be moved relative to the plate 103
~ t
~ -~8-
5~
, it is bia e~ iJ~ en~a~emcr-t ~ith an upp~r cr~ o~ an upri~ht
shaft 1]] and a ~orM ~hcel 11~, mountcd on the shaft 111, is
engagcd by a ~orm 115. The worm 115 i8 secured to the output
shaft of a motor M~ hich replaces the Motor MS of Fi~ures
1 to 1~. The motor r~sl is connccted in an electrical circuit
hereinarter described.
A switching wheel 117 is also secured to the sha~t 111
and a record/playback switch RP is mounted ad~acent to the ~heel
so that an operating member of the switch is operated by a cam
: 119 on the wheel, as hereinafter described. The switch RP has a
first series of contacts for connecting the amplifier A in a
condition suitable for recording incoming messages or reproducing
the answering text, a second series of contacts for connecting
either the fixed head or the movable head H to the amplifier A,
and a further pair of contacts, hereinafter describe~,
Two indents 1~1 and 12~, respectively, are formed in the
periphery of the switching wheel 117 at location. an~ular~y
- ~pa¢ed by approximately 10. An operating member of a microswitch
- 125 i~ biased into engagement with the peri~n ry o, the ~heel 117.
As shown in Figure 5B, one pole of the motor M51 iS
¢onnecte~ to a positive terminal of a battery which has its
~egative terminal connected to earth potential. The other pole
of the motor is connected to earth potential via contacts 2a and
2b of Figure 5A and is also connected to earth via the contacts
of the micros~itch 125.
Referring no~ to Figure 5C of the drawlngs, the electrical
¢ontrol ¢ircuit of the present machine includes a sillcon
~ontrolled rectifler SCR5 ~Ihlch ¢orrePponds to the rectifier SCRl
of Pi~ure 4. A~ in the case of rcctifler SCRl, a gate electrode
o~ rectlfler 8CR5 i~ c~nnectea to an output of a bridgc r¢ctlfler
"
~f.'"
,.. . .
. .
551'76
(not sho~ h in turrl ls connecte~ to a kelephor~o line, A
winding of a relay ~5, Wh1Ch cor~es,ponds to rclay ~1, cor~ects
the anode Or rectifier SC~5 to thc posltlve termirlal of a battcry
and the cathode of the rectifier i~ conncctcd to the ne~ative
terminal. The relay RL5 has a first set of contacts a b c
corresponding to contacts g h i of relay ~Ll and a second set of
contacts d e f for connecting a tape driving motor M and the
amplifier A across the battery terminals.
The contact la of Figure 5A is connected to the anode of
rectifier SCR5 and contact lb is connected via the further pair
of contacts on the switch RP, referred to above, to the cathode
of the rectifier.
When the present mach~ne is connected for use but in a-
~tandby condition the t~pe l~i is in the position shown in Figure 5A,
where the metal foils ~J~l and MF2 has just passed the associated
contacts la, b and 2a, b, respectively. The contacts of re'.ay RL5
are in the cond'tion shown in Figur~ 5~. l'ne contacts of the
switch RP are in conditlons such that tbe flxed head is connected
- to the amplifier A, the amplifier is in a condition ~ultable for
reproducing the answering text, and the further pair of contacts
are ¢losed. The operating member of the microswitch 125 i~ engaged
$n the indent 121 and the contacts of the switch are open.
- When an incoming ringing current is applied to the present
machlne from the telephone line a d.c.voltage is applied to the
gate of rectifier SCR5, the relay RL5 is energised, and the contacts
of the relay are operated to connect the motor M and amplifier A
bet~een the battery terminals and to provide a d.¢.path across the
telsphone line. Wlth the motor M energised and the varlous
ampl~fier and he~d connectlon3 ln the condition~ described above,
the ta~e 101 1~ driven aroun~ lt~ loop and the an~worin~ text
,
~ 3~ ~
~$ Y , ,
,, ~ , ,,,,, , , ~
1055176
recordcd on the t~pe is -tr~n-;mitt~ via the ~elep}~one llne.
Whcn th~ tape 101 has almost cotnple-tod onc traver~;c o~
the loop, and the end of the ans~Jerinr, tcxt h~s heen reached, the
foil MF2 short circuits contacts 2a and 2b. This cau~es operation
of the motor MSl to rotate the ~10rm 115, and hence to rotate the
shaft 111 and the switching wheel 117.
Rotation o~ the switching ~heel 117 disengages the cam
g from the operating member of the s~litch RP. This connects
. the movable head H to the amplifier A in place of the fixed head,
switches the amplifier A to a condition suitable for recording an
incoming message, and opens the further pair of contacts in the
switch RP. Rotation of the switching ~lheel lli also causes the
operat~ng member of the microswitch 125 to be disengaged from the
indent 121, closing the cont2cts of the switch. This mean~ that
1~ current continues to be supplied to the ~otor MSl after the foil
MF2 b~s moved beyor.d the contacts ^a, ~
. . ; ,.
When the switching wheel 117 has mov~d through apDroxlrl,~tely
10 the opératinp, member oP the switch 125 engage~ tAe in~cnt 12~,
openlng the contact~ of the switch and disc^nnecting the motor ~1
~0 fran the battery. ffl e rotation of t,he ~haft 111 therefore ceases.The rotation o~ the shaft 111 whlch has taken pl~ce has
been accompanled by a small movement of the shaft in an axial
directlon, and engagement been the ~haft and the plate 103 has
been sufflcient to bend the spring plate 105 by a gmall amount,
thereby to effe¢t a small movement o~ the head H lateraliy of the
tape 101. Thlg Movement of the head }I means that thé head ls
~llghtly of~et from the optlrnum recordlng por-;ltion but by an
amount whl¢h i~ not ~l~nlflcant.
~ tlnued rotatlon of the ta~e cause~ the metal foil MPl
to *h~rt circult thc contact~ la, b. ~in¢e ~he further palr Gf
cant~t~ ~n th~ ~itch ~P are open, thl~ ha~ no crfcct.
Th~ t~po 101 n~ ro¢~¢a~ to trav~r~ lt~ loop rOr a
ffOCfJr~l tlmf~ ~r~ ~urln~ thls, tlM~ an ln~unln~ M~317Ual,O Itl rOCOraCd
on the ta~o,
~ " .
~ 105S176
~ cn the tapc 1~1 ha.c; a~mo.~t compl~te~ ita ~ece~
traverse the contact~ 2a, b are aga;.n ~hor-t circtli~ed ~y the
foil MF2. This cua~es the motor MS] to be energi~ed to rotate
the sh~ft 111 and the s~litching wh~el 117. Rotation of the
switching ~heel 117 disengages the operating member of s~itch
125 from the indent 12~ so that the contacts of the s~itch are
closed and the motor ~1 remains energised even af-ter the foil
MF2 has moved beyond contacts 2a, b. The shaft 111 and wheel
117 continue to rotate therefore until the wheel has returned
to the standby position of Figure 5B, where the operating member
of switch 125 is re-engaged with the indent 121 and current supply
to the motor MSl is cut off.
With the switching wheel 117 in the position sho~ in
Figure 5B the operat,ing member of the switch RP is a8ain engaged
with the cam 1.19 so that the contacts of the swltch return the
fixed and movable head~ and the ampli~ler to co~ditiorls ~uitable
ibr playing ~ac~ the ar.swering text~ l'he P~ther pair of ¢ontact~
on the switch RP are closed,
When the metal foll M~l reaches the contacts la, b a ~hort
circult i~ placed acro æ the rectlfierz SCR5, cutting off the
rectifler. Current continues to flow t:hrough the winding of
relay ~L5, via contacts la, b and the further pair of contacts
in switch RP, until the foil MFl has moved beyond con~acts la, b.
When this has happened the relay RL5 ls de-energised, the
contacts of the relay are switched to the condition shown in
Plgure ~C, and the tape driving motor M is cut off.
The machlne of Figures 5A, B and C lnclude~ further
¢Ircult~, not ~ho~n, whlch enable recorded me~age~ to be
~layed back to the o~ner o~ the machine ln the rcver~e order
3~ from ~hi¢h they w~re recorded. Thls can ~o dono by operatln~
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1055176
controls providcd orl thc ma~hirlc or ~y trarl~;mltting audio signal
from a remote location.
The circuits crnployod in opcrating the mach~ne ~rom a ,
remote location includc a tone detector corresponding to the ,~
tone detector TD of Figure 4, transistor circuits correspondin3
to those for transistors Tl, T4 and T5, and a relay corresponding
to relay ~L2. This relay has contacts for reversing the polarity
of the connections to the motor MSl, corresponding to contacts
h ...-... m of relay RL2. The present control circuit also
includes a second microswitch whose operating member engages a
further switching wheel on the shaft 111, this ~urther wheel
having only a single indent in place of indents 121 and 12~. The
second microswitch is connected in a circult with the moto~ MSl,
the battery and ^ontacts 2a, b and is connected inco the circuic
1~ by operatlon of further contacts in the relay corresponding to
reIay ~L~. Still ~urther contacts in the relay,serve to connect
the movJng head H co the amplifier ~Jhen ths machine is re~uired ~
to ~lay back recorded me~sages. . ,
In operating the present machine fi?~m a remote locatlon
an audio si nal is tran~mitted over the telephone line whilst
t~e answering text is being transmitted. This signal is detected
by the tone detector, which produces an output signal to operate
the relay corresponding to relay RL2. The second mlcroswitch
~ no~ connected in the circult in place of microswitch 125, the
connectlons to the ampllfier and heads are changed so that
~e¢orded me~age~ can be played back via the movable head H,
~na the golarlty of battery connectlons to the motor MSl are
q~ tape 101 1~ no~ drlven around thc loop and the last
of the lncomlng me~a~e~ recorded on the tapc 1~ tran~mltted to
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~~" r ~(~55176
the tclephorlc linc. ~Jhcn thc rncss~c hac ~ocn t,~ar),;mLtted and
- the tape ha~ almost cornpleted its tI~averse, the contactC~ 2a, b
are short circuited by thè foll MI~V2, The motor M~l ls now
- energised and the shaft 111 and s~ritching ~heels are rotated.
When the second s~litching ~heel has comple~ed one revolution,
thereby moving the head H down to a positlon ad~acent the track
on which the last but one incoming message was recorded, the
operating member on the second microswitch re-engages the indent
on the second switching wheel. Movement of the head H then
ceases.
- .
-A further switch is provided on the present machine snd
is operated by the head H when the head reaches the last track
on the tape. Operation of the further switch causes the relay
corresponding to re'ay RL2 to be de-energised snd the vari~ls
1~ contscts of the relay to be retu~ned to their initial co~dition~.
The ~ransistor ~1 ceases to hold the gate of reo,ti~ler SCP~.
-~hen tbe foil ~ next, ~,hort circuits cont~ct~ ia, b the machine
i~ cut off.
For local playback the operation of the machlne is glmilar
~0 - to that for remote playback except thzt the output of the
mplifier A is connécted to a loudspeaker. -
m e audio signal employed in operating the above machines
~rom a remote location is generated by an oscillator c~upled to
a lo~dspeaker, which is arranged close to the telephone mouthpiece
2~ at the remote location,
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