CA2001830C

CA2001830C - Cap sealing machine

Info

Publication number: CA2001830C
Application number: CA 2001830
Authority: CA
Inventors: Ronald C. Anderson; David A. Myers
Original assignee: Stahls Inc
Current assignee: Stahls Inc
Priority date: 1988-11-09
Filing date: 1989-10-31
Publication date: 1999-12-21
Anticipated expiration: 2009-10-31
Also published as: CA2001830A1; WO1990005062A1

Abstract

An improved apparatus (10) for thermally bonding indicia to caps comprises relatively movable upper and lower platens (12, 14) with a heat source in one of the platens for heating it. A handle (18) pivotal in a vertical plane raises and lowers the upper platen (12) swinging it through virtually a 90° arc to permit easy positioning of a cap between the platens where they are open. Both platens (12, 14) have curved nesting pressing surfaces (20,20'), the upper platen pressing surface (20) having a concave shape and the lower platen pressing surface (20') having a convex shape with the radius of curvature of the upper platen pressing surface (20) being greater than the radius of curvature of the lower platen pressing surface (20') so that the platens (12, 14) apply equal pressure across a cap disposed between them.
Apparatus (10) further includes a keypad (40) and digital readout screen on the handle for ready viewing and access by the operator and further includes a microprocessor controller for regulating temperature of the heat source and time of the heat cycle.

Description

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5. This invention relates to an apparatus far thermally bonding indicia to fabric and more particularly to a heat sealing machine of a type used for apply~.ng letters and logos to caps.

Conventional cap hr~at sealing machiries of the slam shell type utilize a heated upper platen movable relative to a lower platen between open and closed positions for heat sealing, i.s., thermally bonding, indicia, having thermally activatable adhesive thereon, to a cap in the c~.osed position of the platens. This thermally bonding indici.a; i_naluding letters, numbers and identifying logv~c, is app7.ied to capx by placing the indici.a on a crown of the cap between the platens, applying pressure to force the platens toward one another and at the same time applying heat sufficient to cause the thermal7.y bonding indioia to stick to the cap. After an appropriat~a time intexva,l, the platens are separated and the cap with indicia attached is removed.
Typically, the upper platen is mounted on a vertica7.ly swingable handle and manual force applied by an operator to the handle is used to urge the platens together to supply the pressure necessary to accomplish the heat ~asaling. The design of the prior art machines resulted in incons~.stent and, uneven pressure being applied to the cap and indicia and often times too littJ.e force was applied to effect correct bonding therebetwaen _2_ _ _ - . ..
and a less than optimal bond between the indicia and cap resulted.
The force required by the operator in closing and opening the platens in at least one prior art machine would quickly result in tiring the average operator thus rendering repetitive use on several caps a protracted and disagreeable task.
Furthermore, timing of the duration of platen closure is important so that the bonding malterial melts sufficiently to impregnate the cap so that proper. bonding of the indicia is effected. Often, the duration of platen closure is initiated by the operator or by mechanical means suet by the operator. Often the timer is a clock or wristwatch although other types of timers have been employed. This method of timing results in inconsistency in length of platen closure and that inconsistency can result in an insufficiently bonded cap and indi.cia. If the platens are not closed for a long enough period oi= time that can result in an insufficient bond, and, if the plai~ens are closed for too long, adhesive may bleed through the fabrics and result in ineffective bonding.
The present invention providea an improved apparatus for thermally bonding indicia to caps, which apparatus is extremely simple to use and requires a minimum of physical effort so that several caps may be done successively without tiring the operator.
The apparatus includes a solid state control system that monitors temperature, indicates to an operator when the apparatus is ready for heat sealing, automatically initiates a timing cycle upon platen closure to effect a consisteni~ duration of heat sealing time and alarms the operator to separate: the platens after the proper duration of platen closure time has expired.
Another feature of the invention is the provision of upper and lower platens that are shaped such. that the upper platen has a kd:~j _3_ X001830 concave pressing surface of a larger radius of curvature than that of the lower platen which has a convex pressing surface so that equal pressure is applied across the cap and indicia by the pressing surfaces of the platens in the closed position.
Another feature of the invention is the provision of a physically easily operated machine wherein a linkage is provided enabling the operator to open, close and lock together and thereafter unlock and open the platens with a relatively small exertion. At the same time, the upper platen is swung through substantially a 90~ arc between open and closed positions, and the operating handle is swung through a. smaller arc. An adjuster is provided for adjusting pressure between the platens in the closed position to assure proper pressure ~therebetween.
Generally speaking, the present invention provides apparatus for thermally bonding heat applied transfer indicia to caps. The apparatus has relatively manually movable upper and lower platens movable between open and closed positions, with a heat source in one of the platens and a handle connected to the upper platen for moving it between 'the open and closed positions.
Control means are mounted on the handle for ready access and visibility by an operator. The control means include a visual readout and keypad for controlling the temperature of the heated platen and setting timing during the duration of platen closure.
The handle has a portion extending downwardly in overhanging relation to the lower platen in the lowered position and in front of the upper platen in both the raised and lowered positions.
The improved apparatus constructed in accordance with the present invention includes a handle pivotal in a vertical plane and to which the upper platen is connected by a linkage that causes the upper platen to move through a greater arc than the handle as the handle is pivoted. The upper platen is movable to a substantially perpendicular position remote from the lower platen to allow lcdjj _ _ . "
maximum working clearance for an operator to load and unload caps on the lower platen.
The lower platen is cantileveredly supported on a lower support arm to allow for loading and unloading of caps in the open position of the platens. The lower support arm includes an adjuster for adjusting the elevation of the lower platen and thereby the pressure between the platens in the closed position.
The lower support arm also includes a mechanism for supporting the lower platen for self-alignment with the upper platen in the closed position of the platens.
The apparatus may include a cap-hold down mechanism for securing the cap to one of the platens for heat sealing indicia on the cap. Such cap hold-down mechani;~m includes a lever and spring with over center locking ability i~o secure a cap on the lower platen in a locked position.
The above features, and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.
Fig. 1 is a perspective view of an improved apparatus for thermally bonding indicia to caps constructed in accordance with the present invention;
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w _...~, 2001$30 STA 76078 ~~ 5 -Fig. 2 is a sides view oi~ the apparatus with a portion of the controls housing removed for clarity and illustrating the handle and platens in closed and open positions;
Fig. 3 is a front view of the apparatus;
Fig. 4 is a bask side view of the apparatus;
Fig. 5 is a froni:al view of the upper and lower platens illustrating their respective radii of curvature;
Fig. 6 is a sectional view taken along lines 6 l0 6 in Fig. 2t Fig. ~ is a detailed view of a keypad mounted on the handle;
Fig. 8 ~.s a detailed view of a visual display mounted on the handle:
Fig. 9 is a gahs~matic side view of the handle linkage mechanism for the upper platen;
Fig. ~o is a cross-sectional view taken on the line 10-10 of Fig. 3; and F~.g. 17, is a b.loak diagram of the electric 2o control circuit.

kith reference i:o Fig. 1 of the drawings an improved apparatus for thermally bo»ding indicia to caps ot~nstructed in accordance with the present invGntian is geneerally indicated by 1t) and is used for therma7.ly bonding indiaia such as letters, numerals and logos to caps. As is mare fully hereinafter described, the improved apparatus 10 is ~~ manual heat saal~.ng machine that is simple in construction and operations.
As shown in Fig's. 1-3 of the drawings, the improved apparatus 10 has relatively movable upper and SENT BY: B&K MT CLEhIENS r . : 10-2'7-89 5 3134690524-j 819 '7 i0 8847: # '7 -_ __ ...
.~ 8TA 76479 ,-~ 6 -lower platens 12,14 movable between ari open position shown in phantom in Fig. 2, and a closed positian wherein both platens are in relative close proximity. Upper platen 12 includes a heat source in the form of a resistance heater 13 (show;n schematically in Nig. li) for heating the upper platen to provide sufficient temperature far effecting a thermal bond between the indiaia and a oap. A handle is comprising a pair of laterally spaced apart arms 18a and 19b, and a handle la portion 18c extending therebetween and secured thereto, is pivotally mounted as at 19 on the base pedestal 2~.a extending upwaxdly from the bases 2~.. The handle 18 is pivotal by the operator in a vertical plane for raising and lowering the upper platen 12. The handle 18 is a~.sa movable relative to the upper platen lZ to provide over-center locking of the up;~er and lower platens in the closed position of the platens wherein the platens are urged together to provide sufficient pressure to affect the thermal bonding.
As shown in Figs. 3 and 5 of the drawings, the upper and lower platens 12,14 have nesting pressing surfaces 20,20' respectively. Aa shown in Fig. 5, the upper platen pressing surface 20 has a concave shape and the lower platen pressing a:urface 20' has a convex shape.
The radius of curvature p~ of the upper platen pressing surface 20 is~greater than the radius of curvature B of the lowex platen pressing ~~urface 20' so that the platens properly nest in the closed position shown in Fig. 3 and generally the~xeby equal pressure is appl~.ed across the surfaces of a cap disposed between the pressing surfaoes of the platens in th~a closed pasition. with further reference to Fig. 3, the lawer platen 14 includes a compressible heat resistant cover 22 which compensates SENT BY:B&K MT CLEhIENS r ;10-27-$9 10:00AN : 3134690524 $19 7'70 $$47;# $
20~~L$,~0 9TA 76079 - 7 ~-Zor irregu7.arities in they cap and indicia so that the irregularities are not pressed ~.nto the indicia during the thermal bonding of the indicia to the cap.
Preferably the compressible heat resistant cover 22 is a silicone pad although other types of heat resistant covers are contemplated for uge with the present invention.
With reference t:o Figs. 2 and 9, the arms 18a and 18b have a torwardly e~aanding section 23 terminating at its forward snd in an angularly related downwardly projecting section 25 whf.ch ie~ pivotally connected as above-mentioned to the pedestal 21a. Thus, handle 18 swings about pivot 19 subectt~ntially as Shawn in Fig. 2.
The platen 14 is carried by lev$r arm means 26 comprising a pair of laterally spaced lever arms 26 a and 26b as shown in Figs. 2, 3, 4, and 9. The forward ends of arms 26a and 26b are pivota~.ly connected at 27 to the platen between upstanding bifurc;ats~d ears 2s and 29. The rearward ends of the arms 26a and 26b are pivotally mounted at 30 to the peclestal 21a. Thus, the upper platen 12 is mounted far vertical swingable movement ab4ut the pivot 30 from they solid outline closed position of fig. 2 juxtaposed an thE~ lower platen 14 to the open z5 position shown in phantom position vertically spaced above and rearward of the lower platen 14. short links 31 and 32, see Figs. 2,4, and 9, are connected at pivots 33 and 34 betws~en the hand~,le 18 and the platen carrying lever arm means 26 to swing platen 12 between open and closed possitians and to p»ovide an ovax center locking action. The arrangement of pivots and spacing therebetween is such that upon swinging handle 18 between the closed position Shawn _'Ln solid outline in ~'ig. 2 and the open position shown in phantom outline, are angular SENT~BY: B&K MT CLEIvIENS ' : 10-2?-89 10: 00~hi : 313460524-~ 81g T70 884?: #

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SmA 760'79 - g -distances of approximately 55~, the upper platen 12 is swung through approxt.matE~ly 80~ between the closed solid outline position and the open phantom outline position.
1t will be noted in Fig 2 that in the open position the upper platen 12 is well removed away from the lower platen i4 so that a cap .may be easily positioned can the lower platen without inter:~erence by the upper platen.
Fig. 9 illustrates more ~~~.early than Fig. 2 the linkage and pivot points arid operation thereof. The handle le and upper platen 12 are shown in solid outline positions ~.ntermediate the open and closed positions. The connection of the link mE~ans 31 to the operating handle 1e and the upper platen support arm z6 is such as to render the operating handle a second class lever arid the support arm a third class lever.
As shown in Figs. 2 and 4, the lever arm means 26 and links 31 and 32 are disposed between the handle arms 18a and 18b. A stop member 34 mounted on lever arm means: Z6 is positionQd to engage and limit the closing 20' mota.on of handle 18, stopping the handle when it has dust passed the ovex-center position of pivots 19, 33, and 34. Thus when handle 18 is pulled down until arrested by stop 34, the platens will .remain closed exerting pressure on a cap disposed therebet:ween as schematically depicted z5 at C in Figs. 1 and Z. The cap brim or visor is illustrated at C1.
Zn the preferred embodiment, the lower platen 14 is cantilsveredly supptfrted an a lower support arm 35 mounted on a hollow pedestal 36 to thereby allow fvr 30 loading and unloading of caps on the lower platen in the open position of the platens. Lower platen 14 is interchangeable on lower support arm 35 by simply lifting the lower p~,aten off the support arm. This allows use of a variety of lawar platens 14 which can thereby SENT BY: B&K htT CLEhIENS : 1D-27-89 10: ~lf~M ; 313469054-3 819 771 8°47; !#1 i 8TA 7b079 - 9 -t~ecommodate naps having different crown heights.
As shown in figs. 2 and 3, the low~ar support arm 35 ~.ncludes a pregsure~ adjuster 3'~ for adjusting the elevation of the lower platen 14 and thereby the pressure between the platens in they closed position. Adjuster 37 is ~.llustrated. as a rotat;able screw 38 threaded in and extending through the lower support arm 36 and having a handle 39. The upper rt~nd of the screw includes an unthreaded length received in a hale in the bottom of the lower platen and bearj.ng against the platen to raise and lower' it on adjustrnr~nt of t:he screw. The lower platen 14 includes a depending dowel pin 44 loosely received through the lower support arm for self-alignment with the upprrx platen when the platens are in the closed porait~.on. The fit of the unthreaded end of screw 38 in the bottom of the lower platen also allows for a slight amount of play whereby the lower platen virtually floats on the lower support arm 35.
As shown in Fig,. 1, the handle 18 is provided with a housing 42 having a keypad 44 and digital readout 46. The electronic componE~nts and shown schematically in block diagx~am in Fig. 11., The keypad is a pressure-sensitive membrane type switoh available from The Hall Company crf 420 East Water Street, Urbane, Ohio 43078 as Model No. BTHL 1507.. The digital readout is of the 7.iquid crystal diode type available from several sources.
Within the housing there ins a micro-processor controller shown at 47 in Fig, z1. A preferred embodiment is available from Intel Corporation of 3065 Hovers Avenue, Santa Clare, California 95057., as Model No. 87C64-2, for regulating temperature of the upper platen and time of the heat oycle. As shown in Figs. 1 and 8, the digital SENT BY: B~K MT GLEP1ENS : 1D-2'7-$9 10: D2AM ; 313690524-~ $19 '7~G_1 $$4;;
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sTA ~so~~ -readout 46 displays temperature and time. Keypad 44 allows the operator to input ~.nstructions with respect to upper platen iz temperature and time. Keypad 44 allows the aparator to program 'the controller far the time and temperature settings desired. The digital readout 46 indicates when the upper ;platen 12 is sufficiently hot to initiate heat sealing, the duration of platen 12,14 closure after the heat sealing is initiated and causes an alarm to be activated when the heat sealing is completed.
lA
The platen ZZ ~.ncludes a cover i6 within which there is insulation, not shown, to keep the upwardly exposed surface of upper platen at ambient temperature.
A platen temperature ~~engor 49 in the form of a resistance temperature detector (RI'D) is avaiJ.able from Measurements GrOUp, InC. of P.O. Box 27777, Raleigh, NC
27511, as Model number CT-TR-A02-0050, arid is shown schematically in ~'ig. 11. The RTD ~.s disposed within the cover is and includes a printed circuit pr~,nted on 2o platinum car iron a7.loy wh~.ch when heated undergoes a material change in the electrical resistance of the temperature sensor. The temperature sensed is relayed as a signal back tv the microprocessor controller 47 which acts as a thermQStat and through a Triac (ava~.lable from Motorola Semiconductor Products, Inc., of P.o. gvx 20912, Phoenix, Arizona 85036, as Model No. MC88n5) contrais energi~ation of the resistance heater 13 in the upper pXaten 12. The controller is operable to control the temperature in the upper platen 1z, within plus or minus 2 degrees Fahranhe~it, and also tar display that temperature on the digital readout 46 in degrees Fahrenhs~it .

SENT BY: B&K MT CLE~1EfJS ; 10-2 r-89 10: Q3flf9 : 3134690524-3 819 77Q1 884~r; #12 i S'fA 76079 -~ 7.1 The controller writhin housing 42 also includes a tithing function responsf.ve to platen 12,14 closure for timing the during of pl~rt~an closure. An optical switch 52 (see Figs. 4 and lI) connected to the mitsropxocessor 47 indicates that the platens 12, 24 are closed and initiates a timing sequs!nce. Optical switch 52 is Conventionally known as s reflective opto sensor and generates low intensity j'.nfrared light. The infrared light is reflected off av small plate 53 attached to to handle 18 when the handle is brought down to close the platens 12,14. The same optical switch 52 receives back the reflected light and sends a signal. tc~ the m~.croprvcessor 47 tv indicate that the platens 12,14 are closed and to initiate tree timing sequence. A switch such as a TRW reflective opto-sensor Model No. CPB 706A
available from TRW Qptoelectrvnics Division, TRW
Electxanic Components Group of 1215 West Crosby Road, Carrollton, Texas 75005 is suitable for functioning as optical switch 52 although other switches are contemplated for use in the apparatus l0.
The apparatus 20 also includes an audible alarm 55 (available Pram Panasonic, Matsushita Electric Corporation of America, Dne Panasonic Way, Secaucus, New ,lersey, as Model No. RD24C4~1) shown schematically in gig.
11, which is disposed witlhin housing 42 for signalling the expiration of time set for platen 12,7.4 closure. The controller indicates the conclusion of the timing cycle and actuates the audible alarm to notify the operator to ~0 open the platens.
bigital readout 46 provides a visual xeadout of readiness of the heat~sd upper platen 12 for use, temperature of the heated ~>laten, and duration oP plat.en SENT B'Y:B&K MT CLE~~1ENS ;10-27-89 10:03RM ; 3134690524 819 7?0 8841;#13 ..
2002~~0 closure. Input ~.nformation for the digital readout 46 is applied by the oontrolle:r.
Iri Figs. 2, 3, and 6 of the drawings a cap hold-down mechanism or rett~iner 56 is illustrated. Cap hold-down mechanism 56 is generally U-shaped as shown in Fig. 3 and is housed within the pedestal 36. The bight portion 57 is swung up and down by a handle portion 58 between a cap loading posii:ion shown in phantom in Fig.

2 and a cap holding position shown in solid outline. A
spring 60 connected between. the front of the pedestal at s2 and the bight portion holds the retainer in wither the phantom or solid outline positions through its over-center action. In the pv;sitions indicated at 57' the bight pox~ti.on of the retainer engages within the cap at the back and pulls the front of the cap downwardly against the cover 22 on th~a lower platen preparatory to heat sealing indicia on t:he cap. The cap hold-down mechanism 56 secures itgelie in both locked and unlocked positions and is repoaitioriable with the flip of a finger.
While the best mode for carrying out the invention has been described in detail, those ramiliar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention as defined by the following claims.

Claims

1. In apparatus for thermally bonding heat applied transfer indicia to caps having relatively manually movable upper and lower platens movable between open and closed positions with a heat source in one of the platens and a handle connected to the upper platen for moving it between the open and closed positions, the invention characterized by control means mounted on the handle for ready access and visibility by an operator including a visual readout and keypad for controlling the temperature of the heated platen and setting timing of the duration of platen closure, said handle having a portion extending downwardly in overhanging relation to the lower platen in said lowered position and in front of the upper platen in both the raised and lowered positions.

2. The invention defined by claim 1 further including a temperature sensor and thermostat responsive to the temperature of the heated platen, the sensor being connected to a the controller for controlling the heat source to regulate the heated platen temperature and the sensor also being connected to the readout for displaying the temperature of the heated platen.

3. The invention defined by claim 1 wherein a controller includes a timer responsive to platen closure for timing the duration of platen closure.

4. The invention defined by claim 3 wherein switch means is provided responsive to platen closure for initiating timing of the platen closure duration.

5. The invention defined by claim 1 wherein the visual readout provides a digital readout of readiness of the heated platen for use, temperature of the heated platen ands duration of platen closure.