Background of the Invention Joining the abutting edges of resilient vinyl flooring or the like is generally the work of highly skilled craftsmen, since improper sealing of the j oint will allow dirt and moisture to degrade the seam and ultimately encourage excessive wear.

Two common methods of sealing the seam of resilient vinyl flooring is by using a chemical welding process where a liquid vinyl sealant material is in ; ected between the seam edges and which dries through chemical action, or by using a heat welding process involving melting a vinyl welding rod within the seam which bonds the seam edges together. It is generally acknowledged that the process of heat welding creates a more durable and more elastic seam but requires a higher level of skill since the applicator must coordinate several actions smoothly.

Among the actions requiring a high degree of dexterity is: maintaining the tip of the welding gun generally parallel to the surface of the floor during application; applying a consistent downward pressure at the tip of the welding gun on the vinyl welding rod and moving the welding gun at a constant smooth rate over the welding rod, in direct longitudinal alignment with the seam, thus avoiding excessive melting of the welding rod or scorching of the flooring material.

Applicant is aware of United States Patent No. 4,260, 273 which issued April 7, 1981 to Hemperly and Singer for a Seam Sealer Applicator Attaclunent. What is disclosed is a collar having rollers adapted to be placed on the neck of a flexible liquid adhesive squeeze bottle

to provide improved lateral stability and angular orientation toward the work surface. Further, applicant is aware of European Patent No. EP 0 549 059 toVerkalkwhichdisclosesawheeled housing which supports a reservoir for liquid adhesive. The reservoir has an internal plunger, which is in geared communication with the wheels of the housing. As the housing is moved along a floor seam the gearing causes the plunger to be slowly depressed within the reservoir thereby dispensing adhesive from the reservoir at a rate proportional to the wheel rotation.

What is neither taught nor suggested and which is an object of the present invention, is a relatively inexpensive, stable and simple to operate supporting carriage for both the welding gun and vinyl welding rod used for forming a continuous heat welded seam between abutting sections of resilient vinyl flooring.

It is a further object to provide a supporting carriage for both the welding gun and welding rod where the welding gun may be firmly placed within a holder on the carriage so that the tip of the welding gun may be positioned parallel to the surface of the floor and where the vinyl welding rod may be drawn off the holding spool and heat welded within the flooring seam with a consistent pressure as the carriage is advanced smoothly by an operator.

A further object is to provide a supporting carriage having a guide member such as a wheel which, when positioned within the open seam between adj acent sections of resilient vinyl flooring, will follow in that seam so as to permit an operator to advance the tip of the welding gun in general longitudinal alignment with the seam at a smoothly consistent speed.

Summary of the Invention In summary, the present invention may be characterized as a supporting carriage for a floor seam welding apparatus which includes a frame having front and rear ends. Means for smoothly translating the frame over a floor surface, for example wheels, are mounted to the frame for supporting the frame substantially horizontally for translation, for example by rolling, over the

floor surface so as to dispose a longitudinal axis of the frame along a seam in the surface. The frame includes a reel mounting means for mounting a reel of flexible seam-filling rod onto the frame. The frame also includes a gun holder or mount for mounting a welding gun onto the frame in cooperation with a reel of seam-filling rod when mounted on the reel mounting means. The gun mount positions a heated foot of the gun when mounted in the gun mount into close adjacency over the seam when the frame is positioned so as to align the longitudinal axis over and parallel to the seam. The gun mount may include a rigid collar for receiving, in sliding engagement journalled therethrough, the cylindrical body of the gun.

A guide member may be mounted on the frame so as to be disposed downwardly therefrom, and aligned with the longitudinal axis of the frame, for engaging the seam. Further, a handle, for pushing the frame along the seam, may be mounted on the frame.

The wheels may include a pair of wheels, laterally spaced apart, where each wheel of the pair of wheels is substantially equidistant from the longitudinal axis. In particular, the pair of wheels may be coaxial. The guide member may be a tracking disc or wheel or other means for following the seam mounted generally between the pair of wheels.

The reel mounting means may include at least one aperture in the frame, above the wheels, for receiving mounted therein a reel supporting member. The reel supporting member may include a spindle for mounting through the reel. The member may also include an arm extending between the spindle and a frame mounting portion of the member mountable in the aperture, the arm off-setting the spindle from coaxial alignment with the frame mounting portion.

The gun mount may be adapted for holding the gun, when mounted therein, rigidly upright in a vertical plane containing the longitudinal axis so as to dispose a foot of the gun below the frame. The gun mount may angle the gun so as to be inclined forwardly from the foot of the gun, relative to a forward operative direction of translation of the frame. When the frame is operatively disposed so as to engage with the seam the foot of the gun mounted in the gun mount,

the gun may be inclined generally over the pair of wheels. The gun mount may advantageously dispose the foot of the gun mounted in the gun mount generally between the pair of wheels and the handle.

Brief Description of the Drawings Figure 1, is a perspective view of the supporting carriage frame of the present invention.

Figure 2 is a plan view of the carriage frame.

Figure 3. is a sectional view of the carriage frame taken on line 3-3 of Figure 2.

Figure 4 is a left end (rear) view of the carriage frame.

Figure 5 is a sectional view taken on line 5-5 of Figure 4.

Figure 6 is, in partially cut away enlarged view, a welding head guiding a length of vinyl rod into a floor seam, the excess rod trimmed by a knife.

Figure 7 is a partially cut away sectional view taken on line 7-7 in Figure 6.

Figure 8 is, in side elevation view, a further embodiment of the supporting carriage for a floor seam welding apparatus according to the present invention.

Figure 9-is, in perspective view, the supporting carriage of Figure 8.

Figure 10 is, in plan view, the supporting carriage of Figure 9.

Figure 11 is a sectional view along line 11-11 in Figure 10.

Figure 12 is, in partially cut away exploded view, the mounting of the welding rod spool onto a side wall of the gun mount.

Figure 13 is a view along line 13-13 in Figure 12.

Detailed Description of Preferred Embodiments With reference to the drawing figures, wherein similar characters of reference denote corresponding parts in each view, in Figure 1 gun supporting carriage 10 includes a frame 12 having generally parallel sides 14a and 14b. Each of the sides 14a and 14b have a fore and aft section 16 and 18 respectively and a medial section 20. With support carriage 10 placed upon the exposed surface 22 of resilient vinyl flooring 24, aft section 18 extends generally parallel to surface 22 while the forward section 16 is angularly upwardly inclined relative to aft section 18.

Medial section 20 is disposed generally at right angles to forward portion 16. Frame 12 is firmly supported on exposed surface 22 of resilient flooring 24 by fore and aft pairs of wheels 26 and 28 respectively, rotatably mounted on stub axles.

Sides 14a and 14b of frame 12 are maintained in a spaced apart parallel aspect by several cross members. Cross member 30, located at the trailing edge of aft section 18 of frame 12 contains a medially positioned handle 34 which may be grasped by an operator to move carriage 10 in direction A. Further cross members 36a and 36b are located adjacent to medial section 20.

Cross member 36a supports a cylindrical collar or sleeve 38 into which a welding gun 40, illustrated in broken lines, is placed and securely retained. Welding gun 40 may have an adaptor 41, for example the brass adaptor better seen in Figure 6, for interchangeably mounting one or more of the three or four types of commercially available welding heads 43, an SE402 Sinclair Speed Nozzle being illustrated. A guide wheel 43 a better seen in Figure 7 may in one

embodiment guide rod 50 into seam 58 in the floor. As seen in Figure 6, broad knife 45 may be used to trim the excess rod 50 extending above the seam.

Forward section 16 of carriage sides 14a and 14b have transversally aligned slots 42 formed in the upper edge 16a. Slots 42 accept and retain an axle 44 which supports a reel or spool 46 containing a continuous length of vinyl welding rod 50, both of which are shown in broken lines in Figure 3. A guide wheel 52 is mounted on a transverse axle 54, positioned near the lower edge 16b of forward section 16. Wheel 52 may be placed so as to engage within the open seam 5 8 between adj acent sections of resilient vinyl flooring, and when carriage 10 is moved by an operator along the seam 58 in direction A, assists the operator in maintaining the carriage 10 in longitudinal alignment with a longitudinal axis B of frame 12 aligned with the seam.

Welding gun 40 has a welding tip 60 containing a spatulate shaped foot 62 containing an aperture 64 through which the vinyl welding rod 50 may be threaded, once unrolled from spool 46 and, in the embodiment of Figure 1, journalled through guide 66 on cross member 36b.

In operation, the vinyl welding rod 50 is threaded through aperture 64 as better seen in Figure 6 and the leading tip of rod 50 is inserted within seam 58. The carriage is then centered over seam 58 with guide wheel 52 positioned within the seam and the leading edge of the welding rod positioned beneath the spatulate foot 62 of gun 40. As carriage 10 is moved gradually and evenly in direction A along seam 58 the welding rod 50 is drawn off spool 46 and simultaneously inserted and melted within seam 58 by the heated foot of the gun. Since insertion of welding gun 40 into sleeve 38 positions foot 62 adjacent exposed surface 22 of resilient flooring 24, welding rod 50 is pressed onto seam 58 when translation of carriage 10 results in contact by foot 62 with rod 50. This, then, permits the operator to smoothly pass the carriage along seam 58 at a rate consistent with proper melting and smooth finishing of the rod being pressed into the seam. The carriage also permits an operator to glaze over a previously welded seam.

Welding rod 50 may be easilytrimmed to length against cross member 36b with the blade of a knife or the like. Alternatively, a cutter (not shown) may be mounted to cross member 36b to slice rod 50 at the appropriate length for a clean finish.

The frame may be rotated up about wheels 26 to rest reel on the ground to temporarily discontinue contact of the foot with the seam, allowing for re-continuing once the foot is dropped back down to the seam, thereby rotating the reel back to its elevated position.

In the embodiment of Figures 8-13, carriage 10 includes a frame having a gun mount 70 rigidly mounted by shaft 72 to a wheel housing 74. The shaft may be a splined mating into the housing allowing for selective rotatable releasable mounting of the gun mount relative to the housing so that the device may be adjusted to accommodate smaller radius turns (for example one foot diameter seam circles). A laterally spaced apart pair of wheels 74a are rotatably mounted to opposite ends of housing 74 for rolling translation of the frame in direction A when heat gun 40 is mounted within the cavity 76 defined by the collar of the gun mount.

A guide member 78, which as illustrated may be a rigid disc, is mounted to a rigid elongate plunger 80. Plunger 80 is journalled within a bore at a lower end of shaft 72, and as illustrated, may be resiliently slidably mounted therein bearing against resilient helical coil spring 82. The lower end of shaft 72 is mounted through wheel housing 74, supported therein by a coupler 84 having a rigid sleeve 86 mounted therein, coupler 84 mounted within housing 74 so as to rigidly cantilever shaft 72 and gun mount 70 from the wheel housing.

A handle 34'is mounted at the rearward end of gun mount 70 for grasping by a user. A reel 46'having a length of welding rod 50'wound thereon, is rotatably mounted on spindle 88 at the distal end of arm 90. The opposite end of arm 90 is rigidly mounted to a frame mounting portion such as stub shaft 92. Shaft 92 is non-rotatably mated into a corresponding aperture 94 in one side of gun mount 70. The handle may have a bore 34a through it to accommodate running the welding rod through the handle to control the angular orientation of the feed of the rod.

The end 90a of arm 90 may be shaped as a J-hook for snug mounting around stub shaft 92. The exposed end of stub shaft 92 may be knurled or otherwise contain corrugations, teeth, recesses or the like thereon ibr mating with a correspondingly shaped mating surface 96a on the inside of cap 96. Cap 96 is formed with an annular channel 96b extending around surface 96a.

Channel 96b has an opening 96c through the rim of the cap so that with end 90a mounted within channel 96b, arm 90 may extend through opening 96c. Thus, with arm 90 mounted onto stub shaft 92, and with cap 96 mounted so as to mate surface 96a against the non-planar end surface 92a of stub shaft 92, arm 90 is rigidly mounted onto stub shaft 92 at an orientation about axis C determined by the orientation of cap 96 relative to stub shaft 92. A bolt 99 extends along axis C through aperture 94, stub shaft 92, cap 96, for threaded engagement with locking nut 98. Locking nut 98 tightens cap 96 onto stub shaft 92. The bolt also passes through a laterally extending bore through a solid coupler 100 rigidly mounted at the upper end of shaft 72 so as to rigidly secure the upper end of shaft 72 between opposite side walls 70a and 70b of gun mount 70. Coupler 100 has concave non slip surface 100a to assist the gripping of gun 40 within collar 70. As best seen in Figure 10, collar 70 may be U-shaped. Oppositely protruding ends of coupler 100 extend through apertures in walls 70a and 70b of collar 70, one of the protruding ends of coupler 100 being illustrated in Figure 12.

In use, an operator grasps handle 34'and, with gun 40 mounted in gun mount 70, rotates the carriage frame about the axis of rotation D of wheels 74a so as to engage guide member 78 into seam 58 in the floor. This aligns the longitudinal axis E of the frame with the seam, the longitudinal axis being orthogonal to the axis of rotation of the wheels. The carriage frame is rotated about the axis of rotation of the wheels so as to bring the tip of gun 40 into snugly adjacent proximity to seam 58 as described above in respect of the embodiment of Figures 1-7.

As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope ofthe invention is to be construed in accordance with the substance defined by the following claims.