GB2254064A - Supplying adhesive and tape to connect a wallboard joint - Google Patents

Description

2254064 APPARATUS FOR APPLYING TAPE AND ADHESIVE TO WALLBOARD JOINTS This

invention relates to a hand held apparatus for applying joint tape and adhesive over the joints between wallboard sections.

U.S. Patent No. 4,090,914 illustrates an apparatus for applying joint tape and adhesive over the joints between wallboard sections for joining the wallboard sections.

A large and unwieldy tube is filled with joint adhesive or "mud." Traction wheels or drive rollers are mounted on the forward end of the tube or "bazooka" and rolled along the wallboard joint. The rollers are used to drive a drum on which cable is wound. The cable is attached to a piston in the elongated tube or "bazooka" which forms a reservoir for the adhesive or "mud." As the drive rollers or traction wheels are moved along the wallboard joint, the cable is wound on the drum, moving the piston to dispense mud from the front of the tube or "bazooka" adjacent to and beneath tape simultaneously driven by the drive rollers or traction wheels onto the joint.

is 2 Manipulation of the elongated tube or "bazooka,, is unwieldy and requires use of both hands by the user or operator. Further, the tube, when filled with "mud" or adhesive is extremely heavy causing quick fatigue of the operator and considerable downtime in the operation of the device.

is Finally, when the piston which dispenses the "-,,,iudll reaches the top of its stroke, the tube or "bazooka" must be refilled. This causes further delay in effecting application of the adhesive or "mud" along with the tape to the joint. Often, a malfunction of the device is caused by the cable breaking within the elongated cylinder or "bazooka." In such event, there results a time consuming disassembly and repair of the apparatus. Even if the cable does not break, it is highly undesirable for the piston to fully reach the top of its stroke without being at least partially disconnected. This is because the traction wheels or drive rollers when suddenly braked, cause a jerking stop and possible dislodgment of the already applied tape and the continuous dispensing of additional "mud" or adhesive, resulting in an unsightly joint or one that must be cleaned before final preparation.

The apparatus for applying joint tape and adhesive over the joints between wallboard sections disclosed in U.S. Patent No. 4,090,914 is an apparatus which is readily used in the commercial application of tape and joint adhesive or "mud" and, as noted, has serious disadvantages 3 in its use. The apparatus of the present invention reczifies many of the deficiencies of this prior art apparatus.

4 The invention disclosed herein eliminates completely the use of a piston to dispense the "mud" or cement from the apparatus. Rather, the "mud" is pumped directly from a reservoir through the forward portion of a gunlike apparatus provided with a pistol grip for holding the apparatus. The motor which controls the pump on the "mud" reservoir can be shut on and off by the utilization of a trigger switch adjacent to the pistol grip wherein the amount of "mud" or cement which is dispensed can be precisely controlled.

The device is thus rendered light-weight and can be easily manipulated utilizing one hand on the pistol grip and a second adjacent the front of the gun-like apparatus to aim the apparatus along the wallboard joint. This eliminates the fatigue factor, as well as reducing the number of parts utilized in the prior art apparatus.

By way of example, a specific embodiment in accordance with the invention will be described with reference to the accompanying drawings, wherein:

FIGURE 1 is a perspective view of an apparatus for applying joint tape and adhesive over the joints between wallboard sections with the rear portion holding the joint tape spool removed; FIGURE 2 is a side view in elevation of the rear portion of the apparatus of FIGURE 1 illustrating the mounting of the joint tape on the rear of the apparatus; FIGURE 3 is a perspective view of the apparatus of FIGURE 1 as seen from the front of the apparatus of FIGURE 1; is FIGURE 4 is a partial perspective view of the front portion of the pistol- grip housing of the apparatus of FIGURE 3 provided with a bracket for rece-J-.-ing the "mud" dispensing nozzle and tape applying portion of the apparatus; FIGURE 5 is a partial perspective view of the rear portion of the "mud" dispensing nozzle and tape-applying portion of the apparatus of FIGURE 3; FIGURE 6 is a longitudinal cross section of the apparatus illustrated in FIGURE 1; and 6 FIGURE 7 is a perspective schematic view illustrating the operation of the tape cutoff dispensing nozzle and tape-feed components mounted on the "mud" dispensing nozzle and tape-applying portion of the apparatus of FIGURE 1.

7 Referring now to the drawings in detail, wherein like numerals indicate like elements throughout the several views, FIGURES 1 and 3 illustrate an apparatus 10 provided with a hollow barrel 12 terminating in a downwardly extending pistol grip 14. The barrel 12 includes a hollow chamber 16 separated by a wall 18 from a second hollow chamber 20 which extends into the pistol grip 14. The pistol grip 14 and barrel 12 of the apparatus 10 may be formed from a light-weight metal such as aluminum.

Chamber 16 is adapted to receive "mud" or cement adhesive used to adhere wallboard tape to a joint between adjacent wallboard panels. Chamber 16 includes a downwardly extending reduced diameter portion 22 which is received in frictional seated engagement in the inner diameter of a rubber hose 24. Hose 24 may be connected to a pump seated on or in a reservoir of the "mud" (not shown), which pump is driven by an electric motor. The pump will pump the adhesive or "mud" through the hose 24, tubular extension 22 of chambbr 16, and into the chamber 16, until the chamber is filled.

A downwardly extending trigger 26 is slidable in a horizontal slot or opening 29 formed in barrel 12 along the bottom of chamber 20 and is connected at its forward end by a rod 28 extending through wall 18 to a valve mechanism generally indicated by the numeral 30 disposed within chamber 16 which opens and closes an opening 32 in the forward wall 34 of chamber 16 so that the Umud" or 8 adhesive can be dispensed through opening 32 to a llmudll dispensing nozzle and tape-applying support part or head generally designated by the numeral 36 of apparatus 10. The head 36 includes a circular chamber 38 in communication with chamber 16 through opening 32 and a concentric, contiguous opening 40 formed in the rear wall 39 placed in abutment to wall 34 of chamber 16 in barrel 12. Upon opening of the valve mechanism 30, the 11mudll or cement will flow from chamber 16 through opening 32, contiguous opening 40 into chamber 38 and then through a dispensing nozzle 50 having a contiguous passageway 42 between the forward end of chamber 38 and a dispensing opening 118 at the forward end of nozzle 50.

A cylindrical "globe" valve 44 is rotatably mounted by a shaft 51 in a corresponding cylindrical cavity or recess in the body 46 of nozzle 50 between side plates 124. Body 48 can be manually rotated by a lever 49 on one end of shaft 51 to open or block opening 42. The "mud" will flow through opening 42, contiguous opening 48 in the globe valve 44, and out the forward portion of nozzle 50 through opening 118 beneath a pair of tape-applying rollers 52 separated by a central serrated disc 54 adapted to contact and support the central region of a length of joint tape T as discussed hereinafter.

Immediately adjacent each side of one of the rollers 52 is a metal traction wheel or drive roller 56, the periphery of which is provided with teeth 58. The teeth 58 are adapted to contact the joint tape T and increase traction between the tape and the wallboard. The traction wheels or drive rollers 56 are fixed to a shaft 60, along 9 with rollers 52 and disc 54.

Trigger 26 is fixed to the rod 28 intermediate its ends. The right-hand end of the rod 28 has a coil spring 62 disposed thereabout, which extends between the upper portion of the trigger 26 and the rear wall of barrel 12, for a length unsupported by rod 28. Upon movement of trigger 26 rearwardly or to the right as illustrated in FIGURE 6 in horizontal slot 29, coil spring 62 --7i11 be compressed against the interior wall of barrel 12 and will serve to return the trigger to its forward most position within slot 29 upon release of the trigger 26. The forward end of rod 28 is threaded as indicated at 64 and receives a cap or nut 66 which serves as a valve normally seated within opening 32 in wall 34 to close the same. Disposed intermediate the threaded portion 64 of rod 28 and the wall 18 between chamber 16 and 20 of barrel 12 is a rubber grommet 68 having a circular portion 70 and a forwardly extending reduced diameter portion 72. Upon movement of the trigger 26 against the force of spring 62 to the rear of slot 29, the reduced diameter portion 72 of rubber grommet 30 will collapse inwardly within the flexible and larger diameter portion 70 of grommet 68, enabling the rod 28 carrying nut 66 to move to the right as viewed in FIGURE 6, thereby establishing communication between opening 32 and opening 40 in chamber 38 so that "mud" can be pumped through cylindrical neck 22 into chamber 16 through openings 32 and 40 into chamber 38 where it can enter the nozzle 50 via passageway 42, the central opening 48 in globe valve 44, if opened, and be dispensed beneath the rollers 52 and traction wheels 56, through nozzle dispensing opening 118. Release of trigger 26 will enable spring 62 to return the rod 28 to the left as viewed in FIGURE 6 so that nut 66 is again seated within opening 32 to preclude the dispensing of any further "mud."

is The top of trigger 26 includes an upright sliding contact element 74 electrically connected by a wire 76 to the pump motor. A second wire 78 is connected to a copper strip 80 mounted on a bracket 82 disposed within the interior of chamber 20 of barrel 12. The contact 74 on top of the trigger 26, in its rest position and in the position wherein nut 66 is seated within opening 32, rests in contact with a plate 84 of ceramic or nonconductive material on bracket 82 forward of copper strip 80. Upon opening of valve 30 by sliding rod 28 to the right as viewed in FIGURE 6, contact 74 will slide into contact with copper strip 80 when seat or opening 32 is not plugged or closed by nut 66, enabling an electric circuit to be established to the motor driving the pump through wire 78, copper strip 80, contact 74 and wire 76, so that the pump is only operational when opening 32 is uncovered and valve 30 opened. This gives precise control of the dispensing of the "mud" or adhesive from nozzle 50 through opening 118 beneath the tape T applied to the wallboard joint.

Head 36 is attached to barrel 12 by a bracket arrangement shown in FIGURES 4 and 5.

Mounted on wall 34 of barrel 12 is a substantially U-shaped bracket 86 in plan elevation. Bracket 86 includes a pair of legs 88,90 spaced from front wall 34 of 11 barrel 12 by legs 92 and 94, respectively. A bight portion 96 of bracket 86 joins legs 88,90. outwardly from bight 96 is a threaded stud 98 is Extendina The rear wall 39 of chamber 38 of head 36 has an integral plate 100 provided with laterally extending ears 102 adapted to be received behind legs 88,90 of bracket 86 in abutment with wall 34. Downwardly extending tabs 104,106 on rear wall 39 surround stud 98 and a nut 108 locks the plate 100 to bracket 86 with opening 40 in line with nut 66 on valve assembly 30.

This connection permits other tools to be mounted on the barrel 12, which do not form a part of the present invention, as for example, a tool to apply "mud" or adhesive over a wallboard corner joint having a pair of wallboards disposed at right angles to each other to cover the joint; the joint having been initially taped by use of a corner roller, such as roller 177, which is described hereinafter.

Referring specifically to FIGURES 1, 6 and 7, the tape-feeding and cutoff components mounted on head 36 of the apparatus 10 are disclosed in considerable detail.

Extended through opposed openings in side plates 124 is a rectangular tubular housing 141 having a longitudinal slit 142 along the full length thereof. A HpistoW' 143 carrying a slanted knife blade 144 is mounted slidably in tube 141 in such relationship that the blade 144 is in slit 142. The blade extends sufficiently far out of the tube as to cross a passage 146 (FIGURE 7) through which 12 tape T passes on its way to the rollers 52.

Each end of tube 141 is held against longitudinal and rotational shifting by means of a U-shaped bracket 147 (FIGURES 1 and 3) which, in turn, is secured by screws to the adjacent side plate 124. A link chain 148 extends longitudinally through tube 141 and through piston 143, being disposed in a transverse slot in the latter and fixed thereto by a block 149 connected to links of the chain, which block 149 is in turn fastened to the front and rear faces of piston 143 by suitable fasteners 150.

Chain 148 is normally spring-biased to such position that knife blade 144 is fully retracted and is not in blocking relationship to the tape passage 146. Such retraction is effected by an elongated tension spring 151 (FIGURE 7) which is contained in a tube 152 (FIGURE 1). The end of the spring has a ring 153 thereon so as to prevent its passage through tube 152. Tube 152 is fixedly mounted by suitable brackets 154 on a side plate 124.

An actuating cylinder 158 is connected to a source of fluid through a hose 160 and has a piston 162 which is secured to the opposite end of chain 148. The cylinder 158 is secured to a transverse steel plate 161 on a side plate 124. Pulleys 163,164 are rotatably mounted on Ubrackets 147 and have the chain 148 extended therearound.

To achieve cutoff of the joint tape T after the end of a joint is reached, the operator admits fluid through hose 160 into cylinder 158 to retract piston 162 to thereby pull on chain 148 (against the bias of spring 151) 13 until piston 143 and blade 144 have traversed the tape passage 146. Upon exhaustion of fluid from cylinder 158, the return spring 151 then pulls the piston and blade back to the retracted position shown in FIGURE 7.

After the described cutoff, the tape end is no longer adjacent the wall in the vicinity of roller means 52, but instead is adjacent the tube 141 and blade 144. Thus, feed means must be provided to feed the talpe until its end is again adjacent the rollers and the wallboard joint, to thus condition the tool for commencement of taping of a new joint.

In the present form of such a tape-feeding means, suitable frame means 166 are secured between side plates 124 and define therein a passage 110 (communicating with passage 146, FIGURE 7) through which the tape T can be fed to the vicinity of the knife 144. A guide and pivot rod 167 extends longitudinally of the tool between portions of frame means 166, having mounted slidably thereon a block 168 which carries a needle 169 in pivotable relationship. The needle is biased toward one of its piv.oted positions by a flat spring 171. The relationships are such that when block 168 is so pivoted about rod 167 that needle 169 penetrates into tape T, shifting of the block manually forward along rod 167 toward the rollers 52 will cause positive feeding of the tape T as desired.

Block 168 is not only associated with needle 169 but also has mounted thereon a permanent magnet 172, the end of which interacts with the plate 161. Magnet 172 is sufficiently strong that the block 168 and needle 169 will 14 is normally be in the position shown in the drawings. The magnet is also sufficiently strong to prevent any pivoting of block 168 about rod 167 except in response to cam means next to be described. However, the magnet 172 is sufficiently weak that the steel plate 161 may readily separate from the magnet during the tape-feeding operation.

The cam means comprises an inclined region 173 of a side plate 124, and which cooperates with a portion of block 168. Another cam means comprises a U-shaped bracket 174 (FIGURES 1 and 7) which is secured to the frame means 166 and cooperates with an inclined lower edge portion 176 of block 168.

When block 168 approaches the end of its feeding stroke toward the rollers 52, edge portion 176 rides over U-bracket 174 to pivot block 168 about rod 167 until the needle 169 lifts out of the tape. This lifted relationship of the needle continues during return stroke of the block and needle away from the rollers until the inclined region 173 is engaged to pivot block 168 in the opposite direction, and again cause the needle to penetrate into the tape. The length of the positive feed thus achieved is correlated to the spacing between the knife blade and the rollers, and is such as to cause the tape end to be adjacent the rollers for commencement of taping of a new joint. Reciprocable movement of block 168 along rod 167 can be accomplished by hand.

A corner or creasing roller 177 is provided for use during those times when a joint tape is to be placed in a is corner (in a joint between wallboard sections at right angles to each other). Roller 177 is mounted on a yoke 178 which is pivoted to side plates 124. The yoke 178 is fixed to a rotatable shaft 179 mounted between side plates 124 having a pulley 181 at one of its outer ends.

A cable 182 is connected at one end to a tension spring 183 and thus to a side plate 124 (at a U-bracket 147). The cable 182 extends around pulley 181 and also around a pulley 185 on a shaft fixed to a lever 184.

To shift the corner roller 177 into operative position outwardly and above the various rollers 52 and wheel elements 54,56, the operator pivots lever 184 to thus pull on cable 182, thereby causing rotation of pulley 181 in a counterclockwise direction (FIGURE 1). This operates through yoke 178 to shift roller 177 to operative position. Upon release of the lever 184, the spring 183 returns the roller 177 to its illustrated retracted position.

At all times during operation of the present tool to apply tape to a wall, there is mounted in abutting relationship to end face 116 of body 46 of nozzle 50 a "standard" nozzle portion including opening or passage 118. Standard nozzle 50 has the passage 118 therethrough which corresponds in cross-sectional shape to the associated passage 42 in nozzle body 46.

The standard nozzle portion also has a planar end face 120 which lies in a plane parallel to that of the tape T when the tape is being fed through frame means 166 16 and through the tape passage 146 adjacent the knife mechanism. Furthermore, as shown (for example) in FIGURE 3, the end face 120 is directly opposite but spaced slightly from the peripherai regions of roller elements 54 and discs 56.

Thus, as soon as the tape is fed forwardly past the knife mechanism, to the vicinity of the rollers, it is coated an its interior surface with adhesive emanating from passage 118. This adhesive-coated surface immediately engages the wallboard opposite elements 54,56. The adhesive is thus applied indirectly (by means of the tape) to the wallboard.

Due to the above-described operation of the feeding needle 169 and associated parts, the tape T is fed to the vicinity of the rollers in the absence of any rotation of traction wheels 56. This occurs after each cutoff operation. Then, when the tape is disposed between the rollers and the wallboard (being also between the protruding, toothed, edge regions of traction wheels 56 and wallboard), the tool is rolled along the wall (e.g., to impart clockwise rotation of discs 56 as viewed in FIGURE 6) so that there is a feeding or drawing action whereby the tape is fed from a tape roll 200 supported on a spindle between arms 202,204 fixed to the rear of barrel 12. A tension-applying roller transverses the distance between arms 202,204 and sits on tape T as it is fed. AS soon as this action starts, adhesive is coated onto the tape by activating trigger 26.

The standard nozzle portion is quick-connected with 17 is end face 116 in body 46 by means of a U-shaped mounting spring 121 (FIGURES 3, 6) the ends of which are pivoted to side plates 124. The center or base region of the spring 121 is snapped into a groove (FIGURE 6) in the inclined outer face 122 of nozzle 50. When the nozzle is in mounted condition, the base of spring 121 engages two shoulder portions of the side plates.

To mount the standard nozzle portion, spring 121 is pivoted away from the shoulders, following which, the nozzle portion is positioned in abutting relationship to end face 116 of body 46 of head assembly 36. Then, spring 121'is pivoted forcibly until it snaps into the groove in end face 122. This mounting operation is rapid and effective. The nozzle is easily demounted by introducing a screwdriver adjacent one side of the nozzle and popping the spring base out of its groove.

When the tool is to be used to post-deposit adhesive over a tape which has previously been applied to planar sections of wallboard, the originally-applied adhesive is first allowed to dry. The standard nozzle is quickly removed and replaced by a post-deposit nozzle of the type shown in FIGURES 13 and 14 of U.S. Patent No. 4,090,914, which does not form part of the present invention. Such nozzle is mounted by the same spring 121, and in the same way, as described above with respect to the standard nozzle. However, the shape of the post-deposit nozzle is completely different and has an inner wall which extends substantially longitudinally of the tool and then curves around rollers 52, so with the described post-deposit nozzle, adhesive is applied over the joint at a region 18 closely adjacent rollers 52. A post-deposit nozzle for a corner joint can also be mounted on bracket 86 (FIGURE 4) by replacing the whole head assembly 36.

is At the conclusion of a day's taping operazion, the walls of chambers 18 and 38, and the walls of the various passages are coated with adhesive residue. Element 138, having a check valve 139 therein can be connected to a hose and the water turned on. The water then flows through nozzle 138 and check valve 139 to thoroughly clean the apparatus so that it is ready for the next day's operation.

Reverse rotation of the traction wheels 56 and the rollers 52 is prevented by a pawl wedge 105 which is seated by a tension spring 107, mounted on tube 141, between the teeth 58 of one of discs 58. Counterclockwise rotation (in FIGURE 6) of the discs 56 is prevented by compression of spring 107 in this direction. Thus, the traction wheels 56 bite into the wallboard and rotate in a clockwise direction only.

The lever 49 connected to the shaft 51 of globe valve body 48 can be used to open and partially re-close passageway 42 to nozzle 50 to slow the feed of "mud" or adhesive as required simultaneously with feeding of the tape from the tape roll 200.

Z 19

Claims (6)

1. Apparatus for supplying adhesive and tape to connect a wallboard joint comprising:

(a) a reservoir chamber adapted to contain adhesive, (b) pump means to effect progressive expelling of adhesive from said chamber for application to a wallboard joint, (c) an elongated hollow barrel having a chamber in communication with said pump means, said barrel having a pistol-grip extending downwardly from said barrel for holding said barrel, (d) head means provided at one end of said barrel chamber to dispense and direct adhesive therefrom to a predetermined location, (e) tape drive roller means mounted rotatably on said head means and adapted to roll along a wallboard joint in response to movement of the apparatus to dispense a length of tape over adhesive dispensed by said head means, and (f) trigger means on said barrel for controlling the operation of said pump means to expel adhesive from said reservoir through said barrel chamber and head means beneath said tape as it is dispensed.

2. The apparatus of claim 1 including: passage means provided in said head means and communicating with the interior of said barrel whereby adhesive may flow through said passage means in response to said pump means being activated, and valve means connected to said trigger means for closing said passage means simultaneously with deactivation of said pump means by said trigger means.

3. The apparatus of claim 2 including: means to pass joint tape adjacenz said head means and thence to said drive roller means, and means, including a movable knife element, to effect cutting-off of said tape, said cutting means being disposed in the vicinity of an end of said passage means remote from said barrel.

4. The apparatus of claim 2 including: means to removably mount said head means with the inner end of said passage means communicating with an end of said barrel chamber.

5. The apparatus of claim 4 wherein said removably mounting means includes: nesting brackets on the rear of said head means and --.he front of said barrel.

6. Apparatus for supplying adhesive and tape to connect a wallboard joint substantially as hereinbefore described with reference to and as shown in the accompanying drawings.