US3773597A

US3773597A - Heating apparatus

Info

Publication number: US3773597A
Authority: US
Inventors: K Captain; J Edwards; D Russell
Original assignee: American Velcro Inc
Current assignee: Velcro Industries BV; American Velcro Inc
Priority date: 1971-08-10
Filing date: 1971-08-10
Publication date: 1973-11-20
Anticipated expiration: 1990-11-20
Also published as: CA973786A; GB1388175A; JPS4827848A; IT954644B; JPS5037575B2; DE2228356A1; FR2149753A5

Abstract

A heating apparatus for simultaneously heating a substrate and the under surface of a path to be applied to the substrate in conjunction with means for applying the patch under pressure to a substrate.

Description

United States Patent Captain et al.

HEATING APPARATUS Inventors: Khushroo M. Captain, Cambridge,

Mass; John H. Edwards, Warwick, R.I.; David B. Russell, Ashland, Mass.

American Velcro, Inc., New York, NY.

Filed: Aug. 10, 1971 Appl. No.: 170,611

Assignee:

US. Cl 56/499, 156/285, 156/322, 219/345 Int. Cl. .l B296: 19/02 Field of Search 156/285, 322, 499; 219/345 References Cited UNITED STATES PATENTS 5/1966 Huddleston 156/499 Nov. 20, 1973 FOREIGN PATENTS OR APPLICATIONS 2,012,716 10/1970 Germany 156/499 Primary raminerllarold Ansher Assistant Examiner-M. E. McCamish Attorney-Dean S. Edmonds et a1.

[5 7 ABSTRACT A heating apparatus for simultaneously heating a substrate and the under surface of a path to be applied to the substrate in conjunction with means for applying the patch under pressure to a substrate.

4 Claims, 5 Drawing Figures rump Patented Nov. 20, 1973 3,773,597

IHH

2 Sheets-Sheet 1 FIG. 2

Patented Nov. 20, 1973 3,773,597

2 Sheets-Sheet 2 HEATING APPARATUS BACKGROUND OF THE INVENTION The present invention relates to improvements in patch applicator apparatus of the type which apply sections of hook or loop fastener tape to a web or substrate. An example of such an apparatus may be found in co-pending Ser. No. 134,816, filed Apr. 16, 1971, by the assignee of this application, which is incorporated by reference herein. Such apparatus obviates the necessity of attaching tape sections by sewing or other mechanical fastening means and instead quickly bonds a tape section to a substrate by heat and pressure. Where the substrate is relatively permeable to heat transmission, it is possible to provide a source of heat beneath the substrate which will penetrate through to the adhesive coating upon the under surface of the tape when the tape has been pressed ionto the substrate. However, it has been found that this method is inefficient or unworkable for certain substrate materials, for example where such materials are impermeable to the transmission of heat or where the thickness of the substrate makes such transmission inefficient and slow.

The present invention provides an improved heating means for use in conjunction with a patch applicator of the above type which works equally well with heat permeable or impermeable substrates.

SUMMARY OF THE INVENTION In accordance with the present invention, there is provided in combination with a patch applicator, a heating element and means for interposing such element between the patch applying head and the substrate to which the patch is to be applied. The heating element in this position will rapidly condition a suitable thermally-responsive coating upon the under surface of the patch and the upper surface of the substrate for adhesive pressure bonding of the patch to the substrate. Means are further provided for withdrawing the heating element immediately prior to application of the patch under pressure to the substrate. One aspect of the invention involves the use ofa head which holds the patch against its under surface by means of vacuum pressure. In accordance with such concept, the heating element is constructed to provide a maximum radiant heating area and a minimum interruption of heating area to inhibit the flow of air to the patch holding head, thereby to minimize cooling of the adhesive.

These and other aspects of the invention will be described in connection with the following detailed specification and the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawing and initially to FIGS. 1 and 2 thereof, there has been illustrated a patch applicator apparatus 10. The apparatus has a vertical frame 10a and a base 10b. A substrate 12 is arranged upon the base 10b for the application thereto of a patch 13 applied under pressure by an applicator head 14 which holds the patch prior to and during application. In the particular embodiment, the patch 13 is a section of hook or loop fastener tape and the substrate 12 is relatively thick heat impermeable material. The undersurface of patch 13 is coated with a suitable adhesive which is subjected to heat by the apparatus of the invention prior to the application of the patch to the substrate. The head 14 is hollow and defines in its lower surface 14a a series of apertures 14b. A vacuum is created within the head 14 by a means (not shown) such that a suction force will be applied to the upper surface of the patch 13 to hold it in place against the lower surface 14a of the head.

Head 14 is moved between upper and lower positions by operation of cylinder 16 attached to frame 10a whose actuating rod 17 is connected to the head 14 as shown.

Guides

18a and 18b are movable within fixed cross supports 19 to assure the controlled vertical movement of head 14. As shown in FIG. 2, the guide 18b has an end which when contacted by arms 20, 21 limits the position of head 14 in the upper and lower positions. A multi-cam programmer (not shown) controls the operation of cylinder 16 to raise and lower head 14 in conjunction with other sequential operations of the apparatus 10. Such sequential operations and the movement of the head 14 form no part of the present invention except as movements of head 14 interrelate with the patch heating apparatus of the invention.

As shown in FIGS. l-3 the head 14 mounts a yoke consisting of

arms

26, 27 pivotly connected to the head by a pin 28. Secured at one side of the head 14 is a cylinder mounting plate 29 which is intermediate the arm 26 and the head 14. A spacer 30 separates the mounting plate 29 from the head 14. A retaining collar fits over the pin 28 outside of arm 26 to secure together the assembly of

yoke arms

26, 27 and head 14. Arm 26 has at its upper end an actuating pin 31 which is received within clevis 32 attached to the actuating rod 33 of cylinder 34. At its upper end cylinder 34 is pivotally mounted within a bracket 36 by means of pin 37, the bracket 36 being attached to the plate 29.

The lower ends of

arms

26 and 27 are secured to a heater plate 40 (see FIG. 3) which mounts a heater element 41. The heater element is sinusoidal having ends 42 which have been sprayed with copper to decrease electrical resistance and which are thereafter coated with aluminum oxide for insulating purposes. It will be noted that parallel sections 41a of the heater element are closely spaced and are separated by very narrow gaps 43 so as to providemaximum radiant heating area and minimum space for the passage of air between respective sections 41a. The heater element 41 is secured to plate 40 along two sides by bars 44 and 45.

Terminals

46 and 47 provide current through

leads

48, 49 to the heater element. A flexible cable 50 is held within tubular bracket 51 to the plate 40 and encloses the

leads

48, 49.

Secured to both the mounting plate 29 and guide member 18a, is a horizontal actuating arm 53 which receives an adjustable screw 54. As seen in FIG. 2, when the screw 54 is carried by movement of head 14 and plate 29 from the upper dotted line position to the position of FIG. 2, the lower end 54a of screw 54 will come into contact with a horizontally slidable stop member 56. The stop member 56 is laterally movable within a groove 55a of block 55 which is attached to plate 52. The plate 52 is mounted upon vertical frame a. The stop member 56 has connected to it a pin 57 which rides in a slot 58 in the plate 59 which is movable in a vertical direction by cylinder 60. Slots 59a and pins 65 guide vertical movement of plate 59. The actuation of cylinder 60 is under the control of the aforementioned multi-cam programmer whose sequential operation is such that plate 59 moves downwardly to extend stop member 56 sufficiently to arrest the downward movement of head 14 by virtue of its interconnection with actuating plate 29 and screw 54.

It will be understood that the applicator apparatus 10 includes some means for placing the patch 13 in proximity to the lower surface of head 14 so that the patch can be held by vacuum pressure thereupon. This means forms no part of the present invention and has not been disclosed. It will be sufficient to say that the patch 13 will be initially held by the head 14 when the head is in its upper most position, indicated partially in FIG. 2 by the dotted line position of

members

53,54, and 29 which move vertically with the head.

Furthermore, the plate 40 carrying heater element 41 will be moved from its dotted line position of FIG. 1 into the solid line position of FIGS. 1 and 2, preferably immediately after a patch 13 has been received by head 14. Such movement will take place by actuation of cylinder 34 causing clevis 32 to move upwardly and thus effecting rotation of

arms

26 and 27 about pin 28. Again, movement of plate 40 into its lower horizontal position is preferably initiated by the multi-cam programmer which controls actuation of cylinder 34.

As soon as the plate 40 has assumed its horizontal position, the programmer will actuate the heater element control circuit 60 shown in FIG. 5. The control circuit 60 includes a transformer 61 whose secondary has output voltages of 0, 9 volts, 18 volts and 27 volts. The primary is connected through leads 63 and 64 to a time delay relay 66 having alternate contact positions with

leads

63 and 64. Power to relay 66 is 117 volts A.C. as shown through leads 67 and 68. Relay 66 is so constructed as to permit current to flow initially for say 0.5 second to the primary of transformer 61 through

leads

68, 69 and 67, 64. Consequently the output of transformer 61 to heater element will be 27 volts for this initial period, which can be varied for example from 0.25 second to 0.75 second. After this initial period, the relay 66 will cause contact to be made between leads 67 and 63 which reduces the voltage output of the secondary 50 percent, i.e., to 13.5 volts, for approximately 2 seconds. Relay 66 may be for example of the type manufactured by the Potter and Brumfield Division of AMF Incorporated, model CLB-51-700l0.

The reason for the operation of the relay 66 is to provide an initial quick heating of element 41 followed by sustained heating for a longer period.

After the plate 40 and heating element 41 have been in the solid line position of FIGS. 1 and 2 for approximately three seconds, cylinder 34 will be actuated to extend clevis 32 and to rotate

arms

26, 27 so that plate 40 assumes its vertical dotted line position. Immediately following in sequence, the cylinder 60 will be actuated to urge plate 59 downwardly, causing lateral withdrawal of stop member 56 through the agency of pin 57 in slot 58. This permits the head 14 to continue its interrupted descent and to apply the patch 13 under pressure to the substrate.

The foregoing thus describes a useful addition to patch applicator machines wherein heat is used to prepare adhesive bonding of a patch to a substrate. The heater element 41 is designed particularly adapted to be used with applicator heads which hold a patch in place under vacuum since the interstices between sections 41a of the element are quite narrow and thus do not permit the passage of substantial amounts of cooling air in the direction of the head 14.

It will be understood that the foregoing description has been of a particular embodiment of the invention and is therefore representative. In order to appreciate fully the scope of the invention reference should be made to the appended claims.

We claim:

1. In combination with an apparatus for applying a patch such as a section of hook and loop-type fastener tape and the like to a substrate said patch having an upper surface and a lower surface coated with an adhesive requiring the application of heat thereto prior to applying said patch to the substrate, said apparatus including a head for gripping the patch along the upper surface thereof, means for moving said head between a first position where said head receives the patch and the undersurface thereof is exposed and a second position where said head applies pressure against the patch to apply same to the substrate, the improvement comprising a heating element, a yoke mounting said heating element, means for pivotally connecting said yoke to said head, means connected to said head moving means for selectively rotating said yoke to selectively interpose said heater element between said head and said substrate and for withdrawing said heating element to a position adjacent to said head, means for selectively arresting movement of said head toward the substrate when the heating element is positioned between said head and said substrate to permit the heating element simultaneously to apply heat to said patch and said substrate, and for selectively withdrawing said arresting means when said patch and said substrate are sufficiently heated so as to permit said head-moving means to move said head toward said substrate to its second position and apply the patch against the substrate.

2. The apparatus of claim 1 which includes a reciprocable plate, means for moving said plate, a mounting block defining a slot for receiving a stop member slidably movable toward and away from the head moving means, said plate defining a slot angularly disposed with respect to said stop member, a pin attached to said member received within the slot in said plate whereby reciprocable movements of said plate cause sliding movement of said stop member, and means connected to said head moving means for contacting said stop member when said member is extended toward the head moving means, to arrest movement of said head toward the substrate and to permit the heating element simultaneously to apply heat to said patch and substrate.

3. The apparatus of claim 2 wherein said head includes vacuum pressure means for holding the patch, and said heating element is a flat generally sinusoidal combination of sections arranged closely together to prohibit substantial passage of air therebetween toward said head.

4. The apparatus of claim 3 wherein electrical circuit means are provided for directing a large amount of current to said heater element for an initial period, followed by a lesser amount of current for a longer period. l

Claims

1. In combination with an apparatus for applying a patch such as a section of hook and loop-type fastener tape and the like to a substrate said patch having an upper surface and a lower surface coated with an adhesive requiring the application of heat thereto prior to applying said patch to the substrate, said apparatus including a head for gripping the patch along the upper surface thereof, means for moving said head between a first position where said head receives the patch and the undersurface thereof is exposed and a second position where said head applies pressure against the patch to apply same to the substrate, the improvement comprising a heating element, a yoke mounting said heating element, means for pivotally connecting said yoke to said head, means connected to said head moving means for selectively rotating said yoke to selectively interpose said heater element between said head and said substrate and for withdrawing said heating element to a position adjacent to said head, means for selectively arresting movement of said head toward the substrate when the heating element is positioned between said head and said substrate to permit the heating element simultaneously to apply heat to said patch and said substrate, and for selectively withdrawing said arresting means when said patch and said substrate are sufficiently heated so as to permit said headmoving means to move said head toward said substrate to its second position and apply the patch against the substrate.

4. The apparatus of claim 3 wherein electrical circuit means are provided for directing a large amount of current to said heater element for an initial period, followed by a lesser amount of current for a longer period.