US 3651305 A
A thermal activator for use in the seaming of adjacent sections of carpeting. The activator comprises a heater body with a protective heat insulating means on its bottom surface and a handle carried above the heater body by a handle attachment section extending from one side of the heater body. In seaming carpeting with heat activatable adhesive tape the activator may be positioned so that the heater body is under the edges of the carpet sections to be joined, with a strip of heat activatable adhesive tape between the carpeting and the heater body's top surface, the adhesive surface of said tape contacting the abutting edges of the carpet sections and the non-adhesive surface of said tape contacting the heater body, and the handle is above the carpeting. The heater body is raised to a temperature sufficient to make tacky the adhesive on the tape by contacting the non-adhesive surface of the tape and may then be moved along the tape by the handle during the operation of seaming the carpet segments together.
Description (OCR text may contain errors)
United States Patent Shimota [451 Mar. 21, 1972  APPARATUS FOR CARPET SEAMING  Inventor: Robert E. Shimota, Fox River Grove, Ill.  Assignee: The Kendall Company, Boston, Mass.  Filed: Dec. 8, 1969  Appl. No.: 882,944
Primary Examiner-C. L. Albritton Attorney-Robert D. Chodera and T. W. Underhill [5 7] ABSTRACT A thermal activator for use in the seaming of adjacent sections of carpeting. The activator comprises a heater body with a protective heat insulating means on its bottom surface and a handle carried above the heater body by a handle attachment section extending from one side of the heater body. In seaming carpeting with heat activatable adhesive tape the activator may be positioned so that the heater body is under the edges of the carpet sections to be joined, with a strip of heat activatable adhesive tape between the carpeting and the heater bodys top surface, the adhesive surface of said tape contacting the abutting edges of the carpet sections and the non-adhesive surface of said tape contacting the heater body, and the handle is above the carpeting. The heater body is raised to a temperature sufficient to make tacky the adhesive on the tape by contacting the non-adhesive surface of the tape and may then be moved along the tape by the handle during the operation of seaming the carpet segments together.
I 1 Claims, 8 Drawing Figures This invention relates to a thermal activator which may be utilized in the seaming of carpeting by means of heatactivatable adhesive tape to position and apply the seaming tape.
The splicing or seaming of adjacent carpet segments through the use of heat activatable adhesive tape has historically been accomplished by either of two methods. One method previously employed entails placing both carpet segments in a face-down position with adjacent edges in an abutting relationship. A strip of tape .having heat activatable adhesive on one side is laid on the carpet backing with the adhesive coated tape side facing and covering the inter-edge formed by the abutting edges of the carpeting. As used herein, the term inter-edge is defined as the line along which the edges of adjacent sections of carpeting abut eachbther. The tape is then bonded to the carpet backing by application of a heating element to the non-adhesive side of the tape such that the adhesive in contact with the carpet backing is rendered tacky and, upon removal of the heating element, adherent to the carpet backing. Following this operation, the seamed carpeting must be returned to a face-up position for use at its desired site. The second prior method of rug seaming with hot melt adhesive tape is performed while adjacent carpet segments lie face-up on a substrate with edges initially abutting to form a connecting inter-edge. The inter-edge is positioned directly over a strip of hot-melt adhesive tape laid along a surface so that its adhesive coated surface contacts the carpet back sides. An example of this second method is disclosed in US. Pat. No. 3,415,703, issued to Charles D. Burgess on Dec. 10, 1968. in the method disclosed, the adhesive material is made tacky by application of a heated sadiron directly to the hot-melt adhesive. This is accomplished by rolling back the adjacent carpet edges, holding a heated sadiron in contact with the adhesive surface of the seaming tape long enough to render the adhesive material tacky, removing the heated sadiron from the adhesive surface, and re-establishing the abutting relationship of the carpet edges in contact with the adhesive surface ofthe tape.
However, it is immediately obvious that each of these prior 'carpet seaming techniques has serious drawbacks and disadvantages. The first method cannot be performed with the carpeting in place at its permanent site. The carpet segments must be turned face-down before the seaming operation takes place. After the tape is affixed to the carpet backing, the connected carpeting must be turned back to a face-up position, and installed at its intended site. However, most carpeting is somewhat thick and heavy. Consequently, it is unwieldy, awkward to transport, and difficult to manipulate. Therefore, these transportation and turning requirements present a highly objectionable feature of this first method. Considerable energy must be exerted in lifting and manipulating the carpeting. Also, the bond between the tape and carpet segments may be weakened or destroyed during such moving, causing the seam between the carpet segments to be broken. Accordingly, it would be preferable in many instances to carpet seam with a method that can be performed at the site where the carpet is to remain, with the carpeting laid face-up and moving requirements minimized.
The second method mentioned above eliminates some undesirable carpet moving requirements, since the operation may be performed with the carpeting laid face-up at its intended site. However, this method necessitates activating the hot-melt adhesive to a tacky condition while it is separated from the carpet backing. The abutting carpet edges are rolled back from each other, and the adhesive is brought to a tacky state by directly contacting .it with a heated sadiron. The carpet edges must be placed back into an abutting relationship and pressed into the adhesive material while it is still in a thermally softened, tacky condition. To perform this method, the hot sadiron must be placed directly on the adhesive, transforming the adhesive to a tacky material which sticks to the heating iron and whatever else it contacts. The adhesive trans ferred to the heating surface of the sadiron, obviously, is undesirable and may reduce the efficiency of the sadiron. Since the tacky adhesive may be exposed and unprotected on the heated sadiron for at least a short period after removal of the hot sadiron from the adhesive surface, it is vulnerable to accidental spreading onto other objects in the surrounding area, resulting in an extremely undesirable and messy situation.
SUMMARY OF THE lNVENTION The thermal activator of the present invention may be used in a way to avoid the problems encountered in prior methods of connecting carpet segments by hot-melt adhesive tape. Carpet seaming may be accomplished with this invention while the carpet sections are laid in place at their desired permanent site. The adhesive may be heated to a tacky state without direct contact between it and the heating means, eliminating the possibility of adhesive material being transferred to the heating means. Thus, any potentially messy situation resulting from exposure of tacky adhesive on the heating means to foreign objects is avoided. Any possibility of forming an imperfect seam by reason of the adhesive solidifying before being firmly anchored to the back of each of the carpet. segments may be substantially reduced in many instances since heating of the adhesive may be continued during the steps of replacing the carpet edges into abutment with each other and pressing them onto the surface of the adhesive. Seaming with the activator of this invention may also eliminate the necessity for turning the carpeting before and after the seaming operation, thus simplifying the operation and reducing the possibility of the bond between the tape and carpeting being weakened or broken. It is the novel structure of the activator of the present invention which permits it to be used so advantageously in the seaming of carpeting with hot melt adhesive tape.
In accordance with this invention there is provided a thermal activator having a substantially flat, planar supporting and heating surface and a handle attachment section which extends above the surface and the carpeting to be joined for guiding the activator heater body along beneath the carpet edges and underneath the seaming tape used in making the seam. In using the thermal activator of this invention, its heater body may be positioned under the seaming tape so that the non-adhesive side of the tape rests on the activators top surface beneath the edges of the carpeting to be joined. The seaming tape is placed in a threading relationship with the handle attachment section of the activator, which helps guide succeeding portions of tape into proper alignment for seaming the carpet edges as the activator is moved forward along the edges of the carpet segments. Before such movement is initiated, the activator is sufficiently heated so that the contact of the non-adhesive side of the seaming tape by the activator's top surface for a reasonably short period brings to a tacky condition the adhesive on the other side of the tape. The activator is then moved forward along the carpet edges to be joined. As the activator proceeds, the forward portion of the seaming tape, i.e., that part of the seaming tape which extends in front of the heater body, is progressively brought into position between the top surface of the heater body and the carpet backing so that it may be heated to a tacky condition. Concurrently, as the activator proceeds, portions of the tape trail off the rear end of the heater body with its adhesive in a tacky condition and in contact with the carpet backing. Then the adhesive at points on the tape passed by the heater body cools, bonding the tape to the carpet backs with the application of pressure from the face-side of the carpet segments to seam the adjacent segments of carpeting along the inter-edge. A protective element guards the base plate of the thermal activator. This protective element, which may be a pad or other thermally insulating cover, helps avoid damage to floors or other surfaces which might otherwise contact the heated instrument. A method of using the activator of this invention to seam carpeting is set forth in greater detail in another Pat. application, Ser. No. 882,985, filed by Robert E. Shimota, the applicant for the present invention, and Harry J. Dritt.
BRIEF DESCRIPTION OF THE DRAWINGS Other objects and features will appear from the following description of this invention, detailed in reference to the accompanying drawings, in which:
FIG. 1 is a side view of one embodiment of the thermal activator of this invention.
FIG. 2 is a top view of the thermal activator of FIG. 1.
FIG. 3 is a view of the front end of the thermal activator of FIG. 1.
FIG. 4 is a side view of another embodiment of the thermal activator of this invention.
FIG. 5 is an isometric illustration of the front end portion of the thermal activator of FIG. 4.
FIG. 6 is a view of the trailing end of the thermal activator of FIG. 4.
FIG. 7 is an isometric illustration of the relationship between the thermal activator, seaming tape, and carpet segments in position for using the thermal activator of FIG. 1 to seam carpeting.
FIG. 8 shows a front view of the thermal activator of FIG. 1 under the carpet segments in position for seaming carpeting.
DESCRIPTION OF THE PREFERRED EMBODIMENTS One preferred embodiment of the thermal activator of this invention is illustrated in FIGS. 1-3. The activator 1 as shown comprises a heater body having an elongated lead section -2 in the shape of a rectangular parallelapiped with a leading top surface 3, leading side surfaces 4, a leading end surface 5, and a leading base surface 6a. Pointing rearward (to the left as viewed in FIGS. 1 and 2) as an extension of the lead section 2 is a trailing end section 7 of the heater body with inwardly tapering trailing side surfaces 8 and a trailing top surface 9 sloping downward from the line of juncture 10 with the leading top surface 3 of the lead section to a level somewhat closer to' the trailing base surface 6b extending rearward in the same plane as leading base surface 6a, at which level the trailing end section terminates in a narrow trailing end surface 11. The trailing end surface 11 could suitably be constructed as a flat surface, a curved surface, or simply as an edge between said trailing top surface and said trailing base surface. Since the leading base surface 6a and the trailing base surface 6b are coplanar and in fact may be integral with each other, they will be jointly referred to hereafter as the common base surface 6. Both leading side surfaces 4 of the lead section, both trailing side surfaces 8 of the trailing end section, and the leading end surface 5 are shown in the preferred embodiment as substantially perpendicular to the common base surface 6. It is to be understood that these end and side surfaces may be inclined at an angle to or from the base surface 6. The heater body of the activator, consisting of the combined lead section 2 and trailing end section 7, is constructed of a heat conducting, preferably metallic, material. The heater body may be made from a solid block of metal, machined or molded to the shape described. Alternatively, the heater body may be hollow, being fabricated from, for example, metal plates and fabricated to the shape shown. Located within the heater body is a suitable electric heating coil, the particulars of which are not shown since they are not part of the invention.
Extending from a forward position at one side of the lead section 2 is a handle attachment section 12. From the lead section, said handle attachment section extends upward a short distance above the top surface 3, then bends inward to a point 13 above the approximate transverse middle of the lead section 2. At this point the handle attachment section 12 extends further upward and joins the handle 14. The handle is constructed of a heat resistant, thermally insulating, preferably dielectric material, and it usually extends in a rearward pointing direction, substantially parallel to the leading side surfaces 4 of the activator.
The activator also includes heat insulating means at the bottom surface of the heater body. The insulating means shown in the activator of FIGS. 1-3 is a protective pad 15 of heat insulating material covering the common base surface 6. The protective pad 15 is removable, being fastened in position about the narrow trailing end surface 1 l and attached to the leading end surface 5 by one or more fastening mechanisms such as snap fasteners 16. The protective pad prevents scorching, burning, or scratching of the floor or other surface upon which the activator might rest while in a heated condition. The heater body of the activator is preferably heated by an electrical heating element situated inside the lead section 2. However, it also could be suitably heated by any of a variety of other means, both electrical and non-electrical. Where an electrical heating element within the main body is used, current may be directed to the heating element through convenient insulated conducting wires 18 entering the activator through a portal 19 at the rear tip of the handle section 14, and extending through the interiors of the handle section, the handle attachment section 12 and the lead section 2 to a heating element within the heater body. A light 20 on the leading end of the handle section, or elsewhere on the activator, may serve as a visible signal means to show when the activator is heating or when it is connected to an electrical supply.
Another embodiment of the thermal activator of this invention is shown in FIG. 4. In that embodiment the heat insulating means consists of a protective plate 21 of solid material, such as a metal, which is spacially gapped from the top surfaces 3 and 9 and serves as a shield to cover the common base surface 6. This protective plate 21 is spaced from all or substantially all points on the common base surface 6 of the heater body, providing an air gap 22 which insulates the protective plate 21 from the heated activator. One or more supports, such as shown at 23, may be utilized to maintain the spacing between the protective plate and the common base surface. Where utilized, these supports should be constructed so as to conduct little or no heat from the heated portion of the activator to the protective plate. This can be achieved by using heat insulating material in the supports or by allowing contact between the supports and the heater body only over a very small area. The protective plate 21 is removably attached to the heater body at both the leading end surface 5 and the trailing end surface 1 1. In this embodiment, the fastening mechanisms at the leading end surface may be pins or plugs 24, as shown in FIG. 5, extending from the lead portion 25 of the protective plate into openings 26 in the leading end surface 5. Thermally insulating rings 27 may be used to separate the protective plate lead portion 25 from the activator leading end surface 5. The protective plate may be unfastened from the leading end surface 5 by temporarily bending the lead portion 25 to remove the plugs 24 from the openings 26. As shown in FIG. 6, at the trailing end the protective plate is bent to form one or more hooks 28. These hooks 28 may be removably inserted into an opening 29 recessed in the trailing end surface 1 1 to attach the protective plate to the heater body at that point. After the protective plate 21 has been unfastened from the leading end surface 5, as explained above, it may be separated from the trailing end surface 11 by merely sliding the hooks 28 out of the opening 29, thereby completely detaching the protective plate from the activator.
FIGS. 4-6 also illustrate another feature that may be incorporated onto the activator. The heater body may include guide rails 30 raised along the edges 31 of the top surface 3. These guide rails 30 preferably should extend from points near or adjacent the leading end surface 5 for at least some distance along the top surface edges 31. The guide rails help guide the seaming tape into proper position over the heater body and prevent the tape from slipping off the heater body during the carpet seaming process.
Utilization of the thermal activator of FIGS. 1-3 to scam carpeting is illustrated in FIGS. 7 and 8. The carpet segments 32,33 to be joined are laid face-up on a floor or other surface on which a carpet might rest. The carpet segments are placed in an adjacent arrangement, with the edges to be seamed abutting along a connecting inter-edge 34. The thermal activator l is inserted between the carpet segments so that its heater body is under the edges where the carpet segments are to be joined and under a portion of a strip of heat activatable adhesive tape, which is also positioned under the inter-edge. When the activator has been inserted between the carpets properly, the protective pad is in contact with the surface beneath the carpeting. The adjacent edges of the carpet segments overlap at least part of the trailing top surface 9 and leading top surface 3, with the carpet segment on one side of the interedge 34 being held above a portion of the leading top surface 3 by the handle attachment section 12. The handle section 14 remains above the carpeting. The above-mentioned portion of the strip of heat activatable adhesive tape is positioned between the heater body of the activator and the over-lapping carpeting with the carpeting on each side of the inter-edge 34 covering and contacting approximately half the tapes adhesive coated surface when the carpet segments are in an abutting relationship. The forward portion 35 of tape is threaded between the top surface 3 and the inwardly slanting segment 36 of the handle attachment section 12. This threading arrangement assists in guiding the tape to its proper position between the carpeting and activator as the activator is moved in the direction of the forward portion 35 of tape along the inter-edge 34. The forward portion of tape extending ahead of the heater body may be laid out under the carpet sections along the inter-edge or may extend up between the carpet edges, possibly into a tape dispensing means.
After the above-described relationship between the floor, activator, tape, and carpet segments has been established, the activator is heated to a temperature sufficient to bring the heat activatable adhesive 37 to a tacky condition by contacting the non-adhesive surface 38 of the tape with the activators trailing top surface 9 or leading top surface 3 for a reasonably short time. Heating of the activator may be accomplished by closing an electric circuit directed to the heating element by means of the insulated conducting wires 18 entering the activator through the handle section. When the activator has been sufficiently heated, it is gradually moved forward along the inter-edge 34 (to the upper right as viewed in FIG. 7). As the activator proceeds, successive forward portions of tape strip are threaded into proper alignment between the heater body of the activator and the carpet segments. Each succeeding tape segment is retained between the carpet and heater body long enough to insure that that segments adhesive coating becomes tacky. Thus, the adhesive definitely exists in a tacky condition for a time while directly contacting the backing of the abutting carpet segments. When the heated activator moves past a tackified segment of tape, the adhesive on that segment cools and solidifies, adhering to each of the carpet segments and seaming them together with a firm bond along the connecting inter-edge. If desired, downward pressure may be exerted on portions of the carpeting along the inter-edge while the adhesive is in its tacky condition and the portions of the abutting carpet segments are overlying the top surface 9 of the trailing end section 7 in order to insure a firm connection between the tape and carpet backing. By continuing this procedure as the activator is moved along the length of the inter-edge, the carpet segments become securely seamed along their abutting edges. The slope of the activators trailing top surface 9 permits a smooth transition of the seamed carpeting from a position above the heater body of the activator to the floor, so that the seam will not be weakened by a sudden drop.
The top surfaces of the heater body of the thermal activator provide solid support for the seaming tape, when pressure, such as hand pressure, is applied to press the carpet backing down onto the tape during seaming. This support is especially important when the seaming operation is being performed on carpeting over a resilient or spongy pad, such as when seaming over a carpet underlay pad. In prior art methods of carpet seaming, such as the Burgess method discussed above, if pressure were applied to press the carpeting down onto the tape while lying on a resilient pad, there would be no solid backing to support the tape. The resilient pad would give way under the pressure, reducing the effectiveness of such pressure to increase the bonding between the tape and the carpet backing. With the support provided by the heater body of the activator of the present invention, however, the effectiveness of such pressure in improving the bonding between the tape and the carpet backing is substantially increased.
The simplicity with which carpet seaming may be accomplished by the thermal activator set out herein presents an especially attractive aspect of this invention. This activator may be readily employed to scam carpeting in the home, office, or other location where carpet seaming is desired.
A person skilled in the art of this invention will recognize that there are many embodiments within the scope of this invention besides the above described particular activating device which may be used to achieve the desired objectives. This invention is intended to include all variations and embodiments, limited only to the scope as defined in the following claims.
1. A thermal activator for use in face-seaming of abutting segments of carpet by joining marginal portions along the edges of the carpet segments to a heat activatable adhesive tape, comprising: an elongate heater body having a leading end, a trailing end, and a central portion intermediate the leading and trailing ends, said heater body having a top heating surface extending laterally substantially across the top of the heater body including the central portion thereof, and oppositely disposed thereto, a thermally insulated base surface.
2. A thermal activator in accordance with claim 1 including a handle means for guiding said heater body, said handle means extending from said heater body above said top surface and offset from obstruction across the top surface of the heater body.
3. A thermal activator of claim 1 wherein said heater body includes a spacial gap located between said top and base surfaces extending throughout substantially the length and width of said heater body.
4. A thermal activator of claim 1 wherein said base surface comprises a surface of thermally insulating material.
5. A thermal activator for use in carpet seaming comprising a heater body having a lead section with a leading top surface, a leading base surface, and leading side surfaces and a leading end surface extending between said top surface and said leading base surface and a trailing end section extending from said lead section, said trailing end section having a trailing top surface sloping downward from its line of juncture with said lead ing top surface, a trailing base surface extending rearwardly in the same plane as said leading base surface, and trailing side surfaces tapering inwardly away from said lead section and a narrow trailing end surface between said trailing top surface and said trailing base surface, a thermally insulated handle held above the approximate transverse middle of said heater body by a handle attachment section extending from a side of the heater body, thermal protective means covering both the leading base surface and the trailing base surface, and means for heating said heater body.
6. The thermal activator of claim 5 wherein said means for heating said heater body comprises an electrical means situated in said heater body with conducting wires leading from said electrical means to the exterior of said heater body.
7. The thermal activator of claim 5 wherein said thermal protective means comprises an insulative pad removably secured to the heater body at said leading end surface and at said trailing end surface.
8. The thermal activator of claim 5 wherein said thermal protective means comprises a solid shield removably secured to the heater body at said leading end surface and at said trailing end surface.
9. The thermal activator of claim 8 wherein said solid shield comprises a'metallic plate spaced from said leading base surface and said trailing base surface.
rails extend from points adjacent the leading end surface of the heaterbody along a portion of the top surface edges.