Note: Descriptions are shown in the official language in which they were submitted.
This is a Divisional application of Canadian Patent
`~Application No. 355,938, filed July 10, 1980, entitled ~ 7
"MAGNETIC KEY OPERATED HOTEL DOOR LOCK"
This invention relates to a mechanical magnetic key
operated door lock and is particularly directed to a lockset
adapted for use on the guest rooms of hotels. One requirement
of a hotel lockset is that an occupancy indicator be~ provided
therein to indicate to a maid or others that a door is locked
from the inside as well as from the outside (double locked)
and the room is presumed to be occupied and that no attempt
should be made to enter the room. The conventional type of
occupancy indicator includes a relatively small pin which is
projected outwardly of the outer wall of the outside knob when
a push button on the inner knob is depressed by the guest. Such
depression of the inner button simultaneously double locks the
lockset against an unlocking key or a master key. Such occupancy
indicators for conventional locksets are well known in the art
and one is disclosed in U.S. Patent No. 3,128,618.
One of the aspects of the present invention is the
` provision of an occupancy indicator in a magnetic key operated
door lock and especially one of the type disclosed in U.S. Patent
No. 4,133,194. Said patented structure is adapted to be
actuated by a magnetic key of the type disclosed in U.S. Patent
- No. 4,077,242. Reference is made to said patented structure
for details not herein disclosed.
In the key operated structure of Patent No. 4,133,194
it is extremely desirable to be able to change the combination
of the lockset so that an arriving guest may be provided with a
key differing in its combination from the key used by the
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~ previous guest. This feature, of course, provides greatly
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added security for the new guest. Another aspect of this
invention is therefore to provide not only a means for changing
the combination of a lockset to adapt it for use with a new
key but to permit such a change to be performed rapidly from
outside the lockset without requiring any disassembly of the
latter or removal of the outer knob from the lockset spindle.
Still another aspect of the invention is the provision
- of code changing means asabove described which does not require
the use of the old key or the new key.
Other aspects and advantages will be apparent from
the following specification and from the drawings.
Accordingly, this invention provides, in a magnetic
key operated lockset, an occupancy indicator structure therefor,
including a housing, said housing including a tail piece, a
slidable core containing locking elements, and a pair of plates
between which a magnetic key may be inserted, the improvement
that comprises:
first and second pins slidable axially of said
structure, said core being formed with an opening
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receiving said first pin therethrough,
said first pin being operatively connected to
said tail piece for axial movement of said
first pin upon depression of said tail piece,
; means mounting said second pin for axial movement
in response to said axial movement of said first
pin,
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~ said housing having an outer wall adapted to
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receive one end of said second pin therethrough
upon depression of-said tail piece,
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one of said plates being provided with an opening
for receiving said first pin therethrough for
blocking the entry of such magnetic key when
said tail piece is depressed.
~ ccording to a further aspect, this invention provides,
in a magnetic key operated lockset having a housing, said
housing including a tail piece, a slidable core containing locking
elements, and a pair of plates between which a magnetic key may
be inserted, a lockout structure for said lockset comprising:
10a pin slidable axially of said housing,
said core being formed with an opening receiving
said pin therethrough,
said pin being operatively connected to said
,~ tail piece for axial movement of said pin
to a position between said plates upon
depression of said tail piece to thereby
exclude such magnetic key.
In the drawings:
- Fig. 1 is a side elevation partly in section of an
outer knob structure of a magnetic key operated door lock
suitable for hotel use.
Fig. 2 is an exploded isometric of the essential
elements of the structure of Fig. 1.
Fig. 3 is a cross sectional view through the housing
of Fig. 1 showing only the slidable core.
Fig. 4 is a side elevation of a key of the type
s~ disclosed in Patent No. 4,077,242 but showing a modification
thereof.
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Fig. 5 is a similar view of a key showing a
modification thereof adapting the key for use as a code
changing key.
Fig. 6 is a fragmentary cross section of the slidable
core of Fig. l taken in a plane indicated by lines 6-6 of Fig. 3
and showing the operation of the code change pin carrier.
Fig. 7 is a side elevation of an emergency master key
which is formed in a plurality of parts to provide added
security.
First with reference to Fig. l the general structure
disclosed therin is somewhat similar to that disclosed in
Patent No. 4,133,194 to which reference is made for details not
herein disclosed.
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This structure includes a modified knob generally
designated 10 and a housing generally designated 12. Said knob
and housing being mounted on the conventional door knob spindle
14. The inner knob structure is not shown herein since the
same is conventional and well known in the art. By which such
well known structure a driver bar or tail piece 16, upon its
rotation, unlocks the lockset by retraction of the door latch
(not shown).
Although most of the details of construction are shown
in the above noted Patent No. 4,133,194, a short description of
the operation of the lock is as follows:
A slidable core 18 is adapted to be translated down-
wardly from its upper locked position shown in Fig. 1 by means of
a properly coded key indicated at 20 which may be inserted through
a slot 22 in the sidewall of housing 12. The key 20 is inserted
between a nonmagnetic cover plate 24 and a magnetizable shield
plate 26 so that locking pins in slidable core 18 are magnetically
~ ejected out of corresponding openings in a locking plate 28
;~ which is fixed relative to the housing 12. To simplify the
drawings the locklng pins which are located in slidable core 18
in positions to correspond with the magnetic spots on key 20 are
not shown herein but the operation of the same is clearly
~-~ disclosed in Patent No. 4,133,194. A few holes 21 in locking
, plate 28 are indicated in Fig. 2. A predetermined number of such
holes are adapted to receive therein such locking pins.
` When the locking pins have been retracted back into
~; core 18 out of engagement with locking plate 28 the core 18 may
be moved by the key 20 downwardly against the resiliency of a
spring pressed foot generally designated 30. This sliding movement
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- of core 18 connects for rotation the core 18 and a gear-like
plate 32 so that plate 32 upon rotation of housing 12 rotates
the tail piece 16 to unlock the lockset.
Referring to Fig. 2, it is seen that the tail piece 16
passes axially through a washer 36, a sleeve 38 another washer 40,
a relatively heavy plate 42 and into an opening 44 formed in a
boss 46 integral with the gear plate 32.
By the present invention the tail piece 16 is provided
at its inner end with an enlarged rectangular end portion 50 which
is received within a complementarily formed slot in gear 32. It
will be seen from Fig. 1 that the tail piece may be moved to the
right from its full-line position to its dotted line position
without interference with any of the above noted parts. By the
present invention an elongated pin 54 preferably provided with
an upset end 55 is secured to the inner end of tail piece 16. This
pin 54 extends through a vertically elongated slot 56 in core 18,
through an opening 58 in locking plate 28 and into a hole 60 in
cover plate 24.
Secured at one of its ends to tail piece 16 is a conical
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spring 70 (Fig. 1) which bears at its other end against heavy
; plate 42. By this structure it will be seen that tail piece 16
~ ~ may be moved to the right against the resiliency of spring 70
;ii so that the free end of pin 54 extends through a hole 61 in shield
`~ plate 26 and through hole 71 in flat spring 72 (whose function is
to press plate 26 against plate 24) and into engagement with flat
spring `74. In its projected position pin 54 thus prevents the
~i insertion of a properly coded guest key or master key between
` plates 24, 26. Fixedly secured centrally of flat spring 74 is
~ an elongated indicator pin 76 which is normally received at its
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outer end in a hole 78 formed in the outer vertical wall 80 of
housing 12. It will be apparent from Fig. 1 that upon depression
of tail piece 16, pin 76 will be projected to the dot-dash
position of Fig. 1 indicating that the lockset is locked from
the inside. As is well known in the art, a detent (not shown)
is provided in the inner knob structure to hold the tail piece in
depressed position until the inner knob is turned to unlock the
lockset or a spanner wrench is used to release the knob button.
Upon release of the inner knob button the tail piece 16 is
released so that the same is projected to the left by spring 70
clearing the key slot and permitting the flat spring 74 to which
the indicator pin 76 is secured to return to its original position
with the indicator pin 76 received within hole 78.
It will be understood that not only does the inner
pin 54 project the outer pin 76 to occupancy indicating position,
but it also extends between plates 24, 26, thus physically
preventing full insertion o a conventional guest key or maid's
key into the lockset. A special emergency key for unlocking
the lockset despite the projected pin 54 will subsequently be
described.
Another important feature of the instant invention is
the provision of means for changing the combination of the
lockset from outside the housing as noted above. The structure
for providing thls feature will now be described.
Referring to Figs. 2,3, and 6 the core 1~ is
~' provided with a cylindrical well 81 to receive a cylindrical
plug generally designated 82 which may be formed of nonmagnetizable
material such ?S brass. This plug 82 may be rotated to a
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plurality of predetermined positions and is provided with an
axially extending bore 84 which receives therein a locking pin 86
(Fig. 3). In order to hold the plug 82 in a predetermined position
a radially extending bore 88 is provided in said plug for
receiving therein a compression spring 100. This spring 100
urges a ball 102 radially outwardly of the plug 82 into frictional
engagement with the sidewall of well 81. At spaced points around
the wall of well 81 arcuate grooves 104 are provided for
receiving the ball 102 therein. In the example shown in Fig. 3
four such grooves are formed in core 18 so as to permit positioning
plug 82 in any one of four predetermined positions. A key
properly coded to unlock the lock must also contain in addition
to the normal unlocking spots an additional spot to repel magnet
86 in rotatable plug 82.
For turning the plug 82 a tool generally designated
106 (see Fig. 6) is provided which is formed with a noncircular
end adapted to be received within a complementarily formed hole
108 at the center of plug 82. The shank 107 of tool 106 extends
through an opening 110 in outer wall 80 of housing 12 and under
flat springs 72, 74. Plates 24, 26 are provided with openings
116, 118 and locking plate 28 is provided with an opening 120
for receiving therethrough said shank 107.
~ t this point it will be noted that the combination of
the lockset may be changed from outside the lockset using tool 106
to rotate plug 82 so that magnet pin 86 takes up a different
position so as to register with another corresponding hole in
locking plate 28. Such corresponding hoies are shown at 105 A,
; B, C, D in Fig. 2.
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By the structure of the present invention the shank
107 of tool 106 can be made to register with the hole 108 in
plug 82 only when the core 18 has been depressed to a predetermined
position by a properly coded key. However, it is further
desirable that a key capable of only unlocking the mechanism
does not move core 18 sufficiently to permit registration between
hole 108 and shank 107. If an unlocking guest key were capable
o~ effecting such registration it might be possible to drill a
hole through the key at the correct location and be able to
change combination of the mechanism by inserting a tool through
hole 110 and through the hole in the key and into the plug. To
achieve the desired security an additional magnet pin 130
(Figs. 1,2,3) is provided in core 18 and which pin is normally
attracted to metallic plate 26 through a vertically elongated
hole 132 in locking plate 28. A key properly coded to operate
the lock, but not to change the code, contains a spot 136 on a
key generally designated 138 as showin in Fig. 4. Said spot 136
on key 138 is of opposite polarity relative to the adjacent end
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of maynetic pin 130 and therefore attracts the pin more firmly
~; 20 into locking hole 132. When a properly coded key also containing
; spot 36 is inserted into the lockset slot it will allow magnet
core 18 to be pushed downwardly only to the limit of travel
, allowed by elongated locking hole 132. When the pin 130 engages
. the bottom of slot 132 it prevents further downward movement of
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~ slidable core 18 with the latter in a position not permitting
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registration of the shank 107 of the tool 106 with the hole 108
in plug 82
. Referring now to Fig. 5 which shows a code change key
generally designated 142. This code change key in addition to
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the proper unlocking code, is provided with a magnetic spot 144
having the same polarity as the adjacent end of pin 130 so that
upon insertion of code change key 142 the pin 130 is repelled from
elongated hole 132 permitting the core 18 to be translated
downwardly past is previous limited position so that the hole
108 in plug 82 is in registration with the inserted shank 107
of tool 106.
In order to make the key 142 of Fig. 5 a fully effective
code changing master key the same can be provided with magnetic
spots 143 A, B, C and D all of the same polarity as the adjacent
end of pin 86 so that upon insertion of key 142 in the lockset
the pin 86 will be repelled into plug 82 regardless of its
~i~ particular position. Key 142 is also provided with an opening
145 through which the shank 107 of tool 106 may be inserted when
the core 18 has been moved to its predetermined code changing
position.
Referring back again to the key 138 of Fig. 4, if the
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mner pin 54 of the occupancy indicator is across the key
receiving slot the lockset may still be unlocked by providing
the key 138 with an elongated slot 150 for receiving therein pin
- 54 and thus permit the properly coded key 138 to depress the
core 18 to its unlocking position. This type of key is normally
called an emergency key.
Another key which may be employed for the same purpose
s as key 138 of Fig. 4 is that shown in Fig. 7. In this case
greatly added security may be effected in an emergency key by
forming the key in more than one piece. For example, each
piece may be in the custody of different persons so that joint
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action by such persons is required to permit unlocking of the
lockset when the latter has been locked from inside the door.
In the example given in Fig. 7 three parts 152, 153 and 154 are
shown, and it will be apparent that when said parts are placed
together an emergency key may be formed with the same spot 136
indicated in Fig. 4. In addition, part 153 may be cut away as
indicated at 156 so that when the parts are connected a slot
is formed which is adapted to receive inner pin 54 therethrough.
This emergency key may be used by first inserting part 152 into
the lockset slot and then inserting part 153 hooking the lower
end of the latter around pin 54 and then completing the assembly
by inserting part 154. It will be apparent that carefully
dividing the magnetic key into parts does not appreciably affect
the operation of its code in the mechanism.
A particular advantage derivable from the use of the
key of Fig. 7 is that a magnetic spot 160 may be applied to
; the key in part 153 and between the slot 156 and the leading edge
of the key to operate with a locking pin at that location. This
gives an advantage over the key 138 of Fig. 4 since the formation
; 20 of a slot 150 would remove the magnetic spot 160, preventing
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unlocking.
; Although only one carrier for the code changing pin
8~ has been descrlbed in the form of plug 82, it will be apparent
that additional carriers or plugs may be provided to increase
the possible number of combinations to which the lockset may be
changed. Furthermore, a plurality of plugs may be interconnected
- by teeth to form a gear train to permit a plurality of plugs to
be moved by moving one.
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The present invention also contemplates other means
for rotating the code changing plug in addition to inserting a
tool through a hole in the housing.
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