Note: Descriptions are shown in the official language in which they were submitted.
p Z;~637~
-1- 557-2857
This inven-tion relates to devices for dispensing molten
thermoplastic mi~terials.
Many devices are known for dispensing molten thermo-
plastic materials, such as -the prior art devices described in
United States Patents Nos. 3,204,828 and 3,298,572.
Generally, such devices comprise a barrel member having
an internal melting chamber which communicates with an outlet
opening through a nozzle, and a sleeve with a through opening
having one end secured to the barrel member with its through open-
ing communica-ting with -the end of -the melting chamber opposite the
nozzle. The sleeve is adapted to receive an elongate cylindrical
block of solid thermoplastic material which fits closely within
the through opening in the sleeve, with one end portion of the
block in the melting chamber and the other end portion projecting
through t:he sleeve. Means are provided for heating the barrel
member to melt the end portion of the block therein, and the
device includes a handle positioned so that an operator can grip
the hand].e with the fingers of one hand while pressing ~he bloclc
through t:he sleeve and into the melting chamber with -the thumb of
that hand to force molten thermoplastic material ou-t oE the melt-
ing chamber through the nozzle.
While such devices function effect:ively, a problem can
occur after the operator places a second block of thermoplastic
material end to end with the block in the sleeve and presses on
the outer end of the second block. The operator must hold the
second block in place, thus occupying the operator's second hand,
which may be needed elsewhere such as to manipulate articles to
which the molten thermoplastic material is being applied. If the
~L,2~t~
-2- 557-2857
operator does no-t hold the second block, in place and releases
the pressure on the second block as mus-t be done to stop -the -Elow
of the molten thermoplastic material, or applies pressure in some
direction other tha.n axially along -the second block before its
leading end enters the sleeve, the second block can fall or fly
away from the block already in the sleeve, which is inconvenien-t,
distracting, and wasteful of the operator's time.
A device for dispensing molten thermoplastic material
described in United Sta-tes Patent 4,552,287 provides, among other
things, means for holding and properly positioning a second block
of solid thermoplastic material at the end of a block of that
material already in a sleeve and a melting barrel of a device of
the type described above, even before the second block enters the
outer end of the sleeve, thereby freeing the use oE the operator's
second hand for o-ther activities.
That: device, however, will hold a maximum of less than
three bl.ocks of thermoplastic material, and thus frequent loading
of the device is requlred if the device is used continuously.
Summary of the Invention
The present invention is a modification of the device
described in United States Patent 4,552,287.
Also, preferably at least one inner sidewall of the
magazine is formed with a plurality of recesses parallel to the
axis of the melting chamber and adapted to partially receive the
sides of the blocks, which recesses partia].ly receive the sides of
blocks in the stack and restrict them from moving out the open top
end of the magazine assembly when the device is tipped on its side.
~ Z~37Zki
-3- 557-2857
srief Description of -the Drawing
The present invention will be fu:rther described wi-th
reference to the accompanying drawing wherein like numbers refer
to like parts in the several views, and wherein:
Figure 1 is a side view of a first embodiment of a
dispensing device described in United States Patent 4,552,287;
Figure 2 is a sectional side view of the dispensing
device o:E Figure 2;
Figure 3 is an enlarged fragmentary sectional view of a
barrel member, a sleeve, and a barrier ring therebetween in the
dispensing device of Figure l;
Figure 4 is an enlarged sectional view taken approxi-
mately along lines 4-4 of Figure 2; and
Figure 5 is an end vlew of the dispensing device of
Figure l;
Figure 6 is a side view oE a dispensing device according
to the pr.esent invention which is similar to the device o:E Figure
1 except tha-t :Lt includes a manually operabl.e magazine assembly
for holding blocks of solid thermoplastic material to be dispensed
through the devicei
Figure 7 is an end view of the dispensing device of
Figure 6;
Figure 8 is an enlarged fragmentary sectional view of
the magazine assembly in the device of Figure 6;
Figure 9 is an enlarged perspective view of a slide
included in the magazine assembly in the device of Figure 6; and
Figure 10 is a fragmentary sectional view taken approxi-
mately along line 10-10 of Figure 8.
-4- 557-2857
BrieE Description oE -the Drawing
Referring now -to the drawing -the:re is shown in ~igures 1
through 5 a dispensing device Eor mol-ten thermoplastlc ma-terial
generally des:ignated by the reference numeral 10, which was
described in United States Patent 4,552,287.
Like known prior art dispensing devices for -thermo-
plastic material, -the dispensing device lO comprises a two part
Erame 12, a barrel member 14 mounted between the parts oE the
Erame 12 and having an internal melting chamber 16 communicating
via a discharge passageway 17 through a valve assembly 18 wi-th an
outlet opening l9 through a nozzle 21, and a sleeve 20 with a
cylindrical through opening 22 having one end secured to the
barrel member 14 with its through opening 22 communicating with
the end of the melting chamber 16 opposite the discharge passage-
way 18. The sleeve 20 is adapted to receive a cylindrical block
24 of solid thermoplastic material within the cylindrical -through
opening 22 with a slight clearance fi-t even when the diameter o:E
the block 24 is at the large end of i-ts tolerance range, with one
end portion of the block 24 in the mel-ting chamber 16 and the
block 24
37~
--5--
projecting through the opening 22 in the ~leeve 20. Means
are provided in the device 10 for heating the barrel member
14 to melt the end portion of the block 24 therein. The
frame 12 includes a handle 26 positioned 30 that an
operator can grip the handle 26 with the fingers of one
hand while applying pre~sure with the thumb of that hand to
press the b:Lock 24 through the sleeve 20 and into the
melting chamber 1~ and force molten thermoplastic material
out of the melting chamber 16 through the valve assembly 18
and nozzle 21.
Unlike known prior art devices, the device 10
further includes a bracket as~embly 28 at the end of the
sleeve 20 opposite the barrel member 14, which bracket
assembly 28 includes means adapted for receiving and for
lS holding a second block 24 of solid thermoplastic material
in aligned end-to-end relationship with the block 24 of
thermopla~tic material in the sleeve 20 while affording the
application of force by the thumb of an operator on the end
of the block 24 opposite the sleeve 20 to press the second
block 24 through the sleeve 20 and into the melting chamber
16.
As illustrated, the bracket assembly 28 comprise~
spaced opposed gripping parts 30 of the frame 12 (Figure 5)
that project toward the handle 26 in a position spaced from
the outer end of the sleeve 20 and on opposite sides of an
extension of the axis for the sleeve 20. The gripping
parts 30 are biased toward each other by spring means
comprising a channel-like member 29 of spring ~teel engaged
around the top ~urfaces of the two parts of the frame 12 to
help hold the two partC of the frame 12 t:ogether, and
having opposed arcuate projecting portions 27 that are
biased against the outer surfaces on the gripping parts 30
of the frame 12 The gripping partR 30 have distal ends
spaced at a disltance that is les~ than the diameter oE the
cylindrical block 24 of thermoplastic material, but which
di~tance is sufficient so that thle block 24 can be trans-
versely pressed therebetween to r~esiliently move the
~.Z~ 2~
--6--
gripping parts 30 away from each other in opposition to the
biasing of the projecting portionq 27 and afford movement
of the block 24 therebetween. Also, the gripping parts 30
have concave opposed inner surfaces adapted to conform to
and engage the cylindrical side 3urfaces of a block 24 of
thermoplasti.c material therebetween to hold the block 24 in
alignment with a block 24 in the sleeve 20, while affording
axial sliding movement of the block 24 and movement of the
thumb of the operator between the gripping parts 30 to move
the second block 24 into the sleeve 20.
The device also comprises a pressure plate 32
adapted to abut the end of the outermo~t block 24 of
thermoplastic material opposite the melting chamber 16 and
to be positioned between the block 2~ and the user' B thumb
to transfer force therebetween. The plate 32 includes an
elongate slide portion 33 (Figure 2) at one edge slideably
mounted in a track 34 defined between the parts of the
frame 12 to afford movement of the plate 32 with the block
24 and is shaped to paiss between the gripping parts 30 so
that the plate 32 can be used to push the block 24 fully
into tile sleeve 20 while directing forces applied to the
plate 32 in the longitudinal direction of the block 24, and
protecl:s an operator'~ thumb from contact with the thermo-
plastic block 24 and from contact with any molten thermo-
pla9tic material that (under unusual condLtions) mightextrude to the outer end of the sleeve 20. The pressure
plate 32 includes two wing portionis 35, one projecting from
each side, which wing portions 35 are positioned to pass
under the gripping parts 30 as the pressure plate 32 is
used to press the block 24 into the sleeve 20, and either
of which wing portions 35 can be manually engaged to move
the pressure plate 32 away from the sleeve 20 to facilitate
placing a new block 24 of thermoplastic material between
the gripping parts 30 after a previous block 24 has been
pushed into the i~leeve 20.
The two parts of the frame 12 are molded of a
suitable high-temperature resistant polymeric material
'3'~2t~
--7--
~(e.g., the material commercially designated Dupon, Zytel
FR50-NC10 available from E. I. duPont deNemours, Wilmington,
Delaware). Both parts of the frame 12 are formed with
spaced posts 36 projecting generally radially outwardly of
the barrel member 14, which posts 36 can provide means for
spacing the major side surface of the frame 12 and the
nozzle 21 of the device 10 from a horizontal surface on
which the device 10 is laid, and wh~ch posts 36 have
sockets 37 adapted to receive end portions of a generally
U-shaped wire 31 (Figure 5) to further space the device 10
away from such a surface should that be desired.
The sleeve 20 is made of a ~tiff heat-resistive
polymeric material (e.g., Teflon~) made by an extrusion
process to provide a polished inner surface with micro-
scopic longitudinally extending scratches that facilitates
movement of the thermop]astic material through the sleeve
20, particularly after molten thermoplastic has cooled in
the sleeve 20 and is again heated by the device 10.
The sleeve 20 is coupled to the barrel member 14
by a metal barrier ring 38 (Figures 2 and 3) that is heated
by the means for heating the barrel member 14, which
barrier ring 38 provides means for restricting the extru-
sion of mo:Lten thermoplastic material between the block 24
and t:he inner surface of the sleeve 20. The inlet barrier
ring 38 is a generally cylindrical member having axially
spaced radically outwardly projecting ribs 39 at one end
positioned in a cylindrical socket in tlle end of the barrel
member 14, between which ribs 39 is a sealing strip 40
pressed between the barrier ring 38 and barrel member 14 to
provide a seal therebetween. An end portion 41 of the
barrier ring 38 opposite the barrel member 14 is press fit
into an internally relieved area of the sleeve 20. The
barrier ring 38 has a cylindrical inside surface that is
smaller in diameter than the inside dia0eter of the sleeve
20 (which sleeve 20 is adapted to always receive a block 24
with a slight clearance fit even when the diameter of the
block 24 is at the upper end of its tolerance limits) ~o
~Y 7 ~ e~
~1 2~97~
--8--
that the barrier ring 38 will receive a block 24 having a
diameter at the upper end of its tolerance limitq with a
slight interference fit (e.g., an interference of up to
0.025 cm) or will receive a block 24 having a diameter at
the lower end oE it~ tolerance range with a clearance fit
of about 0.050 cm. Surprisingly those blocks 24 with a
diameter that prc,vides such a slight interference fit with
the barrier ring 38 will be melted sufficiently around
their periphery by the heated barrier ring 38 that they can
be easily pressed into the melting chamber 16, and blocks
24 of thermoplastic material with diameters that provide
either such slight interference fits or clearance fits fit
~uf~iciently close Ln the barrier ring 38 so that no signi-
ficant amount of molten polymeric material will extrude out
of the melting chamber 16 between the block 24 and the
barrier ring 38 and toward the outer ënd of the sleeve 20
between the block 24 and the sleeve 20.
The device 10 also includes three metal (pre~er-
ably brass) cooling flanges around the outer periphery of
the s]eeve 20 that provide means for developing predeter-
mined temperature zones in the sleeve 20, includinq two
closely spaced regulating flanges 45 at the end of the
sleev6! 20 adjacent the barrier ring 38 which cool and
regulate the temperature of the molten thermoplastic
materLal in the area between the barrier ring 3~ and the
sleeve 20, and a cooling flange 48 about centered along the
length of the sleeve 20 that cools the sleeve to restrict
the thermoplastic material from becoming molten past that
area along the sleeve 20, even if the heating means is
activated for a long period of time during which molten
thermoplastic material is not being dispensed from the
device 10.
The barrel member 14 is of a ~uitable metal
(e.g., aluminum). The melting chamber 16 in the barrel 14
is defined by a generally frustoconical inner surface
tapered toward the valve assembly 18 to direct the molten
polymeric material to the dicharcle passageway 17 through
7Z~
g
the valve assembly 18, and four eq~ally ~paced radially
inwardly projecting ribs 42 which provide heated contact
surfaces in addition to the frustoconical inner s~rface for
engaging and ~elting the block~ 24 of thermoplastic
material as they are pressed into the chamber 16. An
electric heating element 43 which heats both the barrel
member 14 and the barrier ring 38 is positioned in a socket
44 in the barrel member 14 beneath the chamber 16, and a
thermostat 46 is fixed in a channel below the heating
element 43 to di~connect electrical power normally supplied
the heating element 43 via a power cord 47 and the thermo-
stat 46 when the temperature of the ba~rel member 14 at the
thermostat 46 exceeds a predetermined maximum (e.g.,
200C).
The valve assembly 18 between the barrel member
14 and the nozzle 21 provides valve means for restricting
molten thermoplastic material from running out of the
nozzle 21 until a predetermined amount of force te.g.,
about 0.9 to 1.8 kilograms) is manually applied to the
block 24 of thermostatic material 24 to cause pressure in
the molten thermoplastic material in the melting chamber
16. The valve assembly 18 is of the poppet valve type and
includes a valve body 49 secured between the barrel member
14 and nozzle 21, which valve body 49 defines the dic~charge
passageway 17 communicating between the melting chamber 16
and the opening 19 through the noæzle 21. The discharge
passageway 17 through the valve body 49 is normally closed
by a head 50 on a valve normally biased against a valve
seat on the end of the valve body 49 adjacent the nozzle 21
by a spring 52 compressed between a flanc~e on the valve
body 49 and a perforated retaining disk 54 fixed on a stem
53 of the valve~ which disk 54 is axially slidably mounted
in the valve body 49. Pressure from molten thermoplastic
material in the melting chamber 16 and discharge passageway
17 caused by pressure manually applied to the block 24 of
thermoplastic material can move the valve head 50 away from
its seat against: the bias of the spring 52 and allow molten
2~j
--10--
thermopla~tic material to pass the valve head 50 and be
discharged through the nozzle 21. When the opera~or
releases such pressure, however, the valve head 50 will
again move to its seat under the influ0nce of the spring 52
to prevent any more molten thermoplastic material within
the melting chamber 16 and discharge passageway 17 from
escaping through the nozzle 21.
'rO use the dispensing device 10, an operator
first connects the power cord 47 to a source of electrical
power so that the barrel member 14 and barrier ring 28 are
heated by the heating element 43. The operator then places
the block 24 of thermoplastic material in the opening 22
through the ~leeve 20, grabs the handle 26 with one hand,
and u~es the thumb of that hand to pres3 against the
pressure plate 32 to slide it along the track 34 into
engagement w:ith the block 24 and thereby press the block 24
through the sleeve 20 and barrier ring 38 and into the
melting chamber 16 in the barrel member 14 where the end
portion of the block 24 will be made molten by contact with
the inner surface of the barrel member 14, including the
inwardly projecting ribs 42. While the inner surface of
the sleeve 20 will provide a clearance fit with the
periphery of the block 24, even if the diameter of the
block 24 is at the upper limit of its tolerance range, the
barrier ring 3~ has a cylindrical inner surface with a
~lightly smaller inner diameter than the inner diameter of
the sleeve 20 and will provide a slight interference fit or
a very close clearance fit with the block 24, depending on
whether the diameter of the block 24 is at the upper or
lower limit of its tolerance range. If there is an inter-
ference fit, the barrier ring 38 will melt the periphery ofthe thermoplastic block 24 sufficiently to allow it to
easily pass; and in either event the barrier ring 38 will
greatly restric:t extrusion of thermopla~itic material from
the melting chcamber 16 back between the block 24 and the
barrier ring 3~ and thus between the block 24 and the inner
surface of the sleeve 20. Sufficient pressure in the
37~
--11--
molten thermoplastic within the melting chamber 16 caused
by manual pressure on the pres~ure plate 32 and block 2~
will cause the head 50 of the value to move away from its
valve seat against the bias o the spring 52 so that the
molten thermoplastic can flow around the head 50 and out
the outlet opening 19 of the nozzle 21. When manual
pres3ure is released on the pres3ure plate 32, the head 50
will again move to its seat under the influence of the
~3pring 52 which stops the flow of molten material through
the nozzle 21 and restricts air from reaching the molten
thermoplastic material in the melting chamber 16, thereby
restricting oxidation of the molten thermoplastic in the
valve a~3sembly 18. IE the heating element 43 remains
activated for a long time while no molten thermoplastic
material is dispensed through the nozzle 21, heat buildup
can cause the block 24 to melt (at least around its
periphery), to about the midpoint of the sleeve 20 where
such melting will be restricted by the cooling effect of
the cooling flange 4~. If the power is then disconnected
so that this molten thermoplastic material cools and
solidifies, and the power is then again connected to heat
the heating element 43, the thermoplastic material in the
valve assembly 18 will be some of the first thermoplastic
material melted and the valve a~sembly 18 can act as a
relief valve for pressure developed in the barrel member 14
as the rest of the thermoplastic material in the barrel
member 14 melts. Also~ the smooth longit:udinally micro-
grooved inner surface of the sleeve 20 wi.ll facilitate
breaking loose of the block 24 from the sleeve 20 to press
it through the barrier ring 38 and into l:he melting chamber
16 to again cause the molten thermoplastiic material to flow
out of the nozzle 21.
When the outer end of the bloc]c 24 of thermo-
plastic materia:l reaches the outer end of the sleeve 20,
the operator can manually retract the pressure plate 32
along it~3 track 34 via one of the wing portions 35 and
press a new block 24 of thermoplastic material transversely
7~
-12-
between the gripping part~ 30 of the holding bracket 2~,
whereupon the new block 24 will be held in proper alignment
with the sleeve 20, and the operator can again u~e the
pre~sure plate 32 to pre~s the new block 24 into the
melting chamber 16.
Referring now to Figures 6 through 10 of the
drawing there is ~hown a dispensing device 60 for molten
thermopla~tic material according to the present invention
which device 60 has the same structure as the device 10
except that the bracket assembly 28 and slide portion 33 of
the device 10 have been replaced by a manually operated
magazine assembly 62. Parts of the device 60 that have the
~ame ~tructures as parts of the device 10 have been given
the same reference numerals to which have been added the
suffix "an.
Like the dispen~ing device 10 the device 60
comprises a two part frame 64, a barrel member 14a mounted
between the parts of the frame 64 and having an internal
melting chamber communicating via a di~charge passageway
through a valve assembly 18a with an outlet opening through
a nozzle 21a, and a sleeve 20a with a cylindrical through
opening 22a having one end secured to the barrel member 14a
with its through opening 22a communicating with the end of
the melting chamber opposite the discharge passageway. The
slQeve 20a i~ adapted to receive a cylindrical block 24 of
solid thermoplastic material within the cylindrical through
opening 22a with a slight clearance fit even when the
diameter of the block 24 is at the large end of its
tolerance range, with one end portion of the block 24 in
the melting chamber and the block 24 projecting through the
opening 22a in the sleeve 20a. Means are provided in the
device 60 for heating the barrel member t:o melt the end
portion of the block 24 therein. The frame 64 includes a
handle 26a posil:ioned 90 that an operator can grip the
handle 26a with the fingers of one hand while applying
pressure with the thumb of that hand to press the block 24
through the sleeve 20a and into the melting chamber to
-13-
force molten thermoplastic material out of the melting
chamber through the valve assembly 18a and nozzle 21a.
Unlike the device 10, the device 60 includes the
magazine assembly 62 at the end of the sleeve 20a opposite
the barrel member 14a, which magazine a~sembly 62 includes
mean~ adapted for receiving and for holding a stack of the
blocks 24 of solid thermoplastic material with the
lowermost block 24 of the stack in aligned end-to-end
relationship with a block 24 of thermoplastic material in
the s~eeve 20a~ while affording the application of force by
the thumb of an operator on the end of the lowermost block
24 opposite the sleeve 20a to pres~ it into the sleeve 20a
toward the melting chamber.
As illustrated, the magazine a~sembly 62
comprises (1) wall means or walls included in the frame 64
that define an open topped magazine chamber 66 adapted to
hold a stack of the solid thermoplastic material blocks 24
with the lowermost block 24 of the stack in aligned
end-to-end relationship with a block 24 of thermoplastic
materLal in the sleeve 20a; and (2) an elongate slide 68
having an end ~urface 69 adapted to engage the end of the
lowermost block 24 opposite the sleeve 20a, a shape adapted
to replace the lowermo~t block 24 in the stack, and an
upper surface 70 adapted to support the other blocks 2~ in
the stack. Also, the slide 68 has portions projecting away
from its side opposite its surface 70 that are
longitudinally spaced to provide! a notch 72 therebetween
opening through its side. The notch 72 is adapted to
receive the end portion of an operator's thumb. The slide
68 is mounted on the frame 64 for movement along a path
generally aligned with the melting chamber (1) from a
retracted position (Figures 6 and 8) with the slide 68 out
of the magazine chamber 66 and its first end surface 69
adjacent the end of the lowermost block in the magazine
chamber 66 opposite the melting chamber (2) to an advanced
position (dotted outline in Figure 6) with the slide 68
extending across the bottom of the magazine chamber 66 to
~ 2;~ 2~i
-14-
pres~ the lowermo~t block 24 in the magazine chamber 66
toward the melting chamber by engagement between its first
end surface 69 and the block 24, in which advanced position
the slide 68 supports the other blocks 24 in the magazine
chamber 66 on its upper surface 70 and (3) back to its
retracted position to allow the block 24 in the stack
adjacent its uppe!r surface 70 to move into alignment with
the melting chamber so that the cycle can be repeated. The
notch 72 is accessible by the thumb of an operator gripping
the handle 26a to afford manual reciprocation of the slide
68 between its retracted and advanced positions by the
operator.
The walls of the frame 64 which define the
magazine chamber 66 include spaced opposed ledges 74 which
define a bottom wall for the magazine chamber 66, and the
slide 68 has opposite longitudinally grooves extending
receive the ledges 74 to afford reciprocation of the slide
68 along the ledges 74 between its retracted and advanced
positions.
Also the walls of the frame 64 defining the
magazLne chamber 66 include spaced vertically extending
side walls 76. At least one of the side walls 76 has a
plurality of recesses 78 parallel to each other and to the
axis of the melting chamber along its inner surface. The
reces~es 78 are spaced and adapted to partially receive the
sides of blocks 24 in the stack of blocks 24 in the
magazine chamber 66 to restrict the blocks 24 from moving
out the open top of the magazine chamber 66 when the device
60 i9 tipped on its ~ide adjacent the recesses 78. Two
resilient spring fingers 77 with enlarged inwardly
projecting head~ on their distal ends and po~itioned
adjacent the open end of the magazine chamber 66 also help
to retain the stack of block~ 24 in the magazine chamber
66, while beincl re~iliently bendable so that their heads
will be cammed out of the magazine chamber as blocks 24 are
added to the sl:ack in the magazine assembly 62.
2~
--15--
To use the dispensing device 60, an operator
fir~t connects its power cord 47 to a source of electrical
power so that the barrel member and barrier ring are heated
by its heating element. After insuring the slide 68 is
then it it~ retracted position (Figures 6 and a), the
operator then places a series of blocks 24 of thermoplastic
material in the open end o the magazine chamber 66, grabs
the handle 26a with one hand, engages the thumb of that
hand in the notch 72 in the slide 68 and uses his thumb to
move the slide 68 along the ledges 74 into engagement with
the lowermost block 24 in the stack to thereby press that
block 24 toward the sleeve 20a and into the melting chamber
in the barrel member 14a where the end portion of the block
24 will be made molten by contact with the inner surface of
the barrel member 14a. As the slide 68 is thu~ moved from
its retracted position toward it~ advanced position (dotted
outline in Figure 6) it will replace the lowermost block 24
in the magazine chamber and support the other blocks in the
magazine chamber 66 on its upper surface 70.
When the outer end of the thermopla~tic material
and the end surface 69 of the slide 68 reach the outer end
of the sleeve lOa~ (the advance position of the slide 68)
the operator can manually retract the slide 68 along the
ledges 74 by engagement of hi~ thumb in the notch 72 or on
one of a pair of projecting wing portions 79, 80 that the
lowermost block 24 of thermoplastic material remaining in
the magazine chamber will move to the bottom o the
magazine chamber 66 in proper alignment with the sleeve
20a, and the operator can again manipulate the slide 68
with his thumb to press the new lowermost block 24 in the
magazine chamber 66 into the sleeve 20a and the melting
chamber.
The present invention has now been described with
reference to one embodiment thereof. It will be apparent
to those skilled in the art that many change~ can be made
in the embodiment described witllout departing from the
scope of the present invention. For example, the device 60
2~i
-16- 557-2857
could incorporate the features described with reference to drawing
Figures 6 and 7 of United States Paten-t 4,552,287. Also recesses
78 of the type illustrated could be used on the other sidewall
defining the magazine chamber 66 instead of the spring fingers 77.
Thus the scope of the present invention should not be limited to
the structures described in this application, but only by struc-
tures described by the language of the claim and their equivalents.
.
