US3611470A - Adhesive spreader - Google Patents

Abstract

AN ADHESIVE SPREADER OF SUBSTANTIAL SIZE IS DISCLOSED FOR THE SPREADING OF FLOORING ADHESIVE OVER A LARGE AREA WITHOUT THE NEED FOR THE MECHANIC TO KNEEL ON THE FLOOR AS HE PERFORMS THIS OPERAION. SUCH AN ADHESIVE SPREADER IS FORMED WITH A 3'' WIDE BLADE HAVING A PLURALITY OF ADJUSTABLE TEETH-LIKE PROJECTIONS BACKED UP WITH A FLEXIBLE STRIKE-OFF BLADE AND AN OVERLYING SET OF PRESSURE FINGERS, ALL RESILIENTLY MOUNTED IN POSITION TO PROVIDE AUTOMATIC COMPLIANCE TO THE NORMAL UNEVENNESS OF CONCRETE FLOORS, AND CAPABLE OF SPREADING A WIDE SWATH OF ADHESIVE IN A UNIFORM, CONTROLLED APPLICATION. A MOUNTING FRAME AND ADJUSTABLE HANDLE STRUCTURE PERMIT THE USE OF THE SPREADER AT THE PROPER ANGLE TO THE FLOOR SURFACE FOR BEST CONTROL OF SPREADING AND AT THE PROPER ANGLE WITH RESPECT TO THE DIRECTION OF TRAVEL SO AS TO DIVERT THE EXCESS ADHESIVE IN THE DESIRED DIRECTION.

Description

061. 12, 1971 1 E. GASTON 3,611,470

ADHESIVE SPREADER F'iled June 8; 1970 3 Sheets-Sheet 1 INVENTOR JACK E. GASTON ATTORNEY Oct. 12, 1971 T N 3,611,470

ADHES I VE SPREADER Filed June 8, 1970 3 Sheets-Sheet 2 INVENTOR JACK E. GASTON ATTORNEY Oct. 12, 1971 J, E, GASTQN 3,611,410

ADHESIVE SPREADER Filed June 8, 1970 3 Sheets-Sheet 3 INVENTOR JACK E. GASTON ATTORNEY United States Patent 3,611,470 ADHESIVE SPREADER Jack E. Gaston, Lancaster, Pa., assignor to Armstrong Cork Company, Lancaster, Pa. Filed June 8, 1970, Ser. No. 43,999 Int. Cl. B05c 11/04 U.S. Cl. 15235.6 4 Claims ABSTRACT OF THE DISCLOSURE An adhesive spreader of substantial size is disclosed for the spreading of flooring adhesive over a large area without the need for the mechanic to kneel on the floor as he performs this operation. Such an adhesive spreader is formed with a 3 wide blade having a plurality of adjustable teeth-like projections backed up with a flexible strike-off blade and an overlying set of pressure fingers, all resiliently mounted in position to provide automatic compliance to the normal unevenness of concrete floors, and capable of spreading a wide swath of adhesive in a uniform, controlled application. A mounting frame and adjustable handle structure permit the use of the spreader at the proper angle to the floor surface for best control of spreading and at the proper angle with respect to the direction of travel so as to divert the excess adhesive in the desired direction.

BACKGROUND OF THE INVENTION Field of the invention of such floors.

Description of the prior art US. Pat. No. 2,913,753 relates to a stand-up type device for spreading a pile of roofing cement over a substantial distance at walking speed. This device, however, incorporates side runners that form the sides of a boxlike unit and, as the back, a rigid, notched blade to allow adhesive to pass out through the notches as the box arrangement is pushed along the roof surface.

A device of this type works for. the intended purpose but will not provide the necessary precision of control over the limited amount of adhesive allowable for the installation of flooring tile. No cement floor is absolutely level, and a rigid blade will bridge from high point to high point allowing excess adhesive to be deposited in the low spots between. This is not harmful in applying roofing felts, but an attempt to install floor tile where too much adhesive has been deposited will cause some to be squeezed up through the joints producing smearing and resulting in the black adhesive being tracked all over the floor surface. In fact, an adhesive spreader for flooring adhesive built on this box principle with side runners and a rigid notched blade was tried but failed to perform satisfactorily for this purpose.

blade to permit the positioning of the fingers for a desirable amount of extension beyond the edge of the blade. The structure is a hand-operated trowel which a gooring mechanic would utilize while kneeling upon the oor.

While it is quite possible that this device would spread flooring adhesive satisfactorily, it would do so only because it is relatively short and is manipulated by hand from a kneeling position so that the mechanic could make several passes over the same area at different angles to remove excess adhesive if he were to pass over a low spot. Here again, the rigidity of the bottom blade which acts (a) as a structural member to which the handle is attached and to which the top blade or blades having fingers are clamped (b) as the guiding means for the fingers, and (c) as the means for striking off or limiting the amount of adhesive allowed to squeeze out between the fingers is so great that if a large blade of this type were to be made and attached to a handle for use in a standing position, it would not perform satisfactorily for applying flooring adhesive for the same reason that the roof cement blade of Pat. No. 2,913,753 proved unsatisfactory. It would bridge from high spot to high spot and leave excess adhesive in the low areas.

In fact, during the development of the stand-up type of adhesive spreader described herein, the only means of achieving satisfactory, uniform coverage of the adhesive over normally irregular, nonlevel concrete floors using a wide 36" blade was through creating a means to achieve controlled flexibility in both the teeth and in the means used to control the depth of the ridges of adhesive exuded between the teeth and beneath the strikeoff blade (screed)..

One object of the apparatus herein described is to provide a stand-up type trowel-type device which will spread adhesive over a substantial area in one pass and be responsive to irregularities in the flooring structure to provide a uniform coat of adhesive.

Another object is to provide adjustability in the angle the teeth make with the floor surface to keep this angle at the proper degree with tall or short mechanics without holding the handle in an unnatural position.

Still another object is to provide a tool that can spread, in a controlled and uniform manner, a heavy ribbon, bead or band of adhesive that has been poured in a contnuous stream the full length of the area to be spread, with the blade of the tool capable of being adjusted as to the angle it makes with the direction of travel of the blade so as to move the excess adhesive to the area yet to be spread regardless of the direction the operator is pulling the tool.

A further object is to provide a precision means of adjustment of the comb-like teeth of the blade, first, to control the amount of adhesive being applied, and second, to permit ready adjustment for wear of the teeth.

SUMMARY OF THE INVENTION The adhesive spreader is made up of a base plate to whcih is attached a comb-like structure which has a plurality of flexible teeth. A flexible sheet and then a plurality of larger spring fingers are mounted over the teeth to provide the teeth with a resilient mounting. A handle is attached to the base and the handle is adjustable so that the spreader may be placed at an angular relationship relative to the direction of travel for the spreader.

A heavy continuous ribbon of adhesive is poured near one wall, for the length of the area to be covered by the adhesive, and the spreader is placed across this ribbon of adhesive with the handle adjusted so that the movement of the spreader in a direction along the ribbon of the adhesive causes the excess material (that is not forced through the grooves between the teeth) to flow across the face of the spreader and discharge at its rearward edge in the direction in which one is planning to continue spreading the adhesive with future passes of the spreader. The operator walks before the spreader and drags the spreader behind him. The resiliently mounted fingers or teeth respond to irregularities in the flooring surface to provide for a uniform coating on the floor surface. At the end of the ribbon of adhesive, the spreader is rotated about the end of the blade from which the excess adhesive has been flowing, the handle is moved so that the end of the blade that had been leading is now trailing and the operator walks back along the side of the newly formed ribbon of excess adhesive with the spreader overlapping a few inches of the swath just covered. With the change in angular position of the blade with respect to the handle, the excess adhesive again moves across the face of the spreader and discharges at the trailing edge-again moving the excess adhesive toward the area yet to be coated. The operator continues to change the angle of the handle with respect to the blade each time he changes direction of movement. When the ribbon of adhesive is nearly exhausted, more adhesive is poured from containers to rebuild the ribbon to adequate volume to continue the full coverage and to permit rolling aside the excess amounts.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a view of the adhesive spreader;

FIG. II is an exploded view of the spreader of FIG. I; and

FIG. III is a plan view of the spreader in use.

DESCRIPTION OF THE PREFERRED EMBODIMENT The adhesive spreader herein comprises (FIG. II) a frame 1 made up of a base plate 2 which is connected by hinge 3 to an angle iron 4. Mounted on the angle iron 4 are means 5 for adjusting the angle of the base plate 2 with the floor. The separate angle iron structure 4 and base plate 2 could be made as a unitary structure, and the adjustability feature, to the extent needed, can readily be achieved by having a handle that is either extensible or is attached to the structure by an adjustable locking yoke. Any other suitable means would also suffice. Mounted on the base plate 2 are brackets 6. Also on the base plate 2 there are grooves 7 in the face of plate 2 to accommodate the heads of bolts 8, which are used to attach the bar 8 to the comb-like structure 9. The comb 9 has teeth 10, and guide slots 11 are positioned on the base plate 2 to guide the teeth of the comb when it ispositioned thereon. Guide slots 11 are not needed if the teeth are clamped tightly against the base plate when the spreader is in use. A flexible screed 12 of polyurethane or other flexible, solvent-resistant material is provided for mounting over the metal comb 9. The importance of the degree of flexibility of this screed will be discussed later.

A set of spring-steel fingers 13 having a metal bar 14 and position guide pieces 15 is provided for mounting over the flexible screed 12 and the metal comb 9. A unit including a channel bar structure 17, a clamping bar 16, comb adjusting screws 18, and the pressure adjusting screws 19 is mounted over the foregoing components with clamping bar 16 being fitted into the slot provided by the guide pieces 15 on the metal bar 14. As best seen in FIG. II, the back ends of the comb 9 are attached to the metal bar 8' by means of bolts 8. The particular comb structure could be made up of a single continuous structure or it could be made up of multiple separate sections thereby allowing adjustability for individual sections. This would also permit changing one short section if a tooth were damaged instead of an entire blade. In the FIG. I assembled form, the channel bar 17, carrying the long adjusting scews 18, would be mounted over the metal bar 8 carried by the comb 9. .Screws 20 are provided for securing the clamping bar 16 to the mounting brackets 6 on base plate 2.

A handle 21 is mounted on the angle iron 4 which also carries means 22 to permit the base plate to be positioned at the desired angle with respect to the handle. A release rod 23 is mounted on the handle 21 for operating ositioning means 22. A support leg 24 can be provided on the handle 21 for holding the handle in an upstanding supported position when the spreader is temporarily not in use.

It will be noted that the adjusting screws 18 threadably aflixed to channel bar 17 are rotatably fitted in the rigid clamping bar 16 which, in turn, is anchored at its ends to the frame of the base plate 2 by brackets 6 and screws 20. When the adjusting screws 18 are turned, the channel bar 17 moves and this moves the spring steel comb 9.

The spring-steel fingers 13 provide additional pressure to force the mob 9 and the screed 12 to follow the contour of the floor. The rigid metal bar 14 distributes the force of the clamping bar 16 to keep the comb teeth 10 in the slots 11 provided in the base plate 2. The comb is made up preferably of .020" thick spring steel, and the ribs 11' separating the guide slots 1 at the end of the base plate 2 are preferably .022" high so that teeth of the comb can be adjusted without releasing the clamping bar 16. As mentioned earlier, the ribs can be omitted if one is willing to release the pressure of bar 14 by loosening screws 19 each time one desires to change the position of comb 9 by turning adjusting screws 18.

In use, the teeth 10 of the comb 9, the screed 12 and the spring-steel fingers 13 are extended about 1%" to 2" beyond the end of base plate 2 and the rigid bar 14 under the clamping bar 16. The tips of the teeth 10 of the comb 9 ride on the floor and, when the handle 21 is raised to its operative height, practically all of the weight of the apparatus is carried by the portion of the comb 9, the screed 12 and the fingers 13 that extend beyond the end of the base plate 2 of the frame 1. A curvature is thus forced into this somewhat flexible extension and portions thereof can give more, or become nearly straight, as the assembly moves across the floor and encounters small irregularities or unevenness. Thus the teeth 10, screed 12 and fingers 13 follow the varying contour of the floor except in extreme cases such as deep gouges or surface protrusions such as a bolt head or a dropped glob of hardened cement or plastic.

The adhesive is applied by the spreader in the form of small ridges of the adhesive that squeeze out between the teeth 10 of the comb 9 and below the screed 12. The spacing between these ridges of adhesive is fixed by the design of the comb 9, but the depth of these ridges of adhesive is controlled by the distance which the teeth 10 extend beyond the end of the screed 12. Thus, as wear occurs on the teeth 10, the amount of adhesive applied can be kept within acceptable limits by adjustment of the extension of the teeth 10 to compensate for the wear.

The degree of flexibility or rigidity of this screed is of utmost importance to the successful operation of the large-blade, stand-up adhesive spreader. It has been found that if the screed is too rigid, the long blade will bridge on high spots in a normally nonlevel concrete floor, and excessive amounts of adhesive will be deposited in the low areas between such high spots. An attempt was made to use a very thin strip of rather flexible spring steel to replace the sheet of polyurethane material used as the screed in order to avoid all possibility of sol-vent attack, but the flexible steel possessed a degree of rigidity that would not let the metallic screed follow the unevenness of the floor and excess adhesive was deposited in the low spots.

In another instance, a replacement screed of polyure thane sheet material was used, and it happened to be cut from a more flexible composition. While this combination followed the unevenness in the concrete floor very well indeed, excessive amounts of adhesive were deposited throughout the full area covered by the blade, and no adjustment of the relative position of the comb-like teeth to the flexible screed would produce the preferred coating of individual, parallel, narrow ribbons of adhesive as wide as the spacing between the teeth and with the height of the ribbons controlled by the screed. Either the ribbons were very high, thus depositing too much adhesive or, when the teeth were retracted to the point that this did not occur, the flexible screed overlapped the teeth so far that it acted as a flat drag and not as a means of controlling the height of the ribbons of adhesive. A change to a stiffer polyurethane sheet corrected the difliculties. What happened with the more flexible sheet screed was that the ribbons of adhesive extruding between the teeth of the comb-like blade developed enough pressure against the bottom of the screed to lift it above its contact point with the top of the teeth thus losing control over the amount allowed to extrude.

We have measured the forces involved in lifting the screed from its position in contact with the top of the teeth of the comb-like blade (when the assembly is in operating position with the teeth curved in the are that occurs when the teeth are supporting the entire weight of the spreader) and find the following relationship between force and amount of movement of the screed:

POUNDS OF FORCE REQUIRED PER INCH OF BLADE LENGTH (The blade tested had 4 teeth per inch) Arrn- Arm- Shore A Durometer hardness of 80. Used screed. (More flexible material) lie" thick.

2 Shore A Durometer hardness of 94. Used as screed. (Stifier material) Ma thick.

For proper operation, the screed should stay in contact with the top of the teeth. The foregoing test revealed that the screed which worked properly required a force of 0.08 pound (0.33 divided by 4 slots per inch) pressing upward between two adjacent teeth to lift the screed off the top of the teeth. The more flexible polyurethane screed required only 0.04 pound of force between adjacent teeth to lift the screed Off the top of the teeth. The steel screed, of course, gave the high value of 0.19 pound to produce lift-off of the screed, but in use it failed because it was not flexible enough and bridged from high point to high point.

In another test, the blade was supported as used in operation with the weight on the teeth thus forcing the teeth into a curved arc. The support was two pieces of plywood that were separated by varying distances to represent high points" to check the ability of the screed material to accommodate to floor unevenness. The maximum amount of irregularity in height that could be accommodated was:

This information clearly reevals the large amount of floor irregularity that can be accommodated by the pre- 6 ferred urethane strickler blade and the bridging action of the steel blade that greatly limits conformation to floor unevenness. The polyurethane blade will handle irregularities up to three times as great as can the very thin steel strickler blade.

The success achieved with the proper type of polyurethane sheet was with Armstrong Cork Companys type PO-652, Shore A durometer hardness of 94 in a thickness.

The adhesive recommended is Armstrongs S190 asphalt-based flooring adhesive. Since the upward pressure on the flexible screed is a function of the viscosity, thixotropy and shear characteristics of the adhesive, it is conceivable that a more viscous adhesive or one with greater resistance to shear or greater thixotropy would require a somewhat less flexible screed than that used successfully in developing the spreader. If an increase in resistance to the upward pressure of the adhesive is needed for some different type of adhesive, this may be obtained by using a slightly stiffer type of sheet material or a thicker sheet of the type P G-6 52 described above. Softer, less viscous adhesives would not require a change in the type of screed used.

Changes in the angle that the comb-like toothed blade makes with the floor were also investigated. Best results were obtained with a blade making an angle with the floor of between 45 degrees and 55 degrees. If too near degrees, the teeth are not curved enough and cannot flex or move a sufficient amount to accommodate the floor unevenness. If too near 0 degree (parallel with the floor), the teeth do not cut through the puddle of adhesive. Rather, the back of tlie base plate 2 comes in contact with the adhesive and a lifting force is developed that is sufficient to cause the entire spreader to float on the puddle of adhesive causing the teeth to lift up and resulting in loss of control of the amount of adhesive being applied.

The preferred angle of 45 degrees to 55 degrees can be achieved by adjustment means 5 as shown on FIGS. I and II or by various other means.

FIG. III shows generally how the spreader is used. The ribbon of adhesive was initially placed in the region 30. As the spreader moved in the direction 31, the adhesive was distributed to cover area 32, and excess adhesive was moved to area 33. Then when the spreader was moved in direction 34, the spreader 35 was angled to place excess adhesive at 36. The operator walks before the spreader and drags the spreader in the direction 37.

What is claimed is:

1. An adhesive spreading structure comprising: a base means, an adjustable handle structure attached thereto and being adjustable to be positioned at different angles relative to the base, said handle constituting a means for moving the adhesive spreader with the operator of the spreader in a stand-up position, a comb-like set of spring teeth mounted on said base means and extending beyond the edge of the base means adjacent to a floor, a resilient sheet material mounted over the top of the comb-like set of spring teeth, and a plurality of spring-steel fingers mounted over said sheet member whereby said combination of comb-like teeth, resilient sheet and spring-steel fingers define a notch structure for spreading the desired thickness of adhesive, which thickness is controllable by providing a means of moving the comb-like teeth in or out with respect to their relationship to the overlying sheet member that functions as a screed, and with the spring-steel finger members providing a resilient back-up for the notch structure to ensure compliance of the notch structure to the normal unevenness of concrete floors.

2. The spreader of claim 1 wherein the comb-like teeth and resilient sheet are at an angle of 45 to 55 degrees relative to the floor.

3. The spreader of claim 2 wherein the resilient sheet is of a stiffness such that at least 0.25 pound per inch is needed to lift the sheet off the underlying spring teeth.

7 4. The spreader of claim 3 wherein the resilient sheet is of a flexibility such that it will cause the spring to conform to at least a 0.10 irregularity when bridging high points 12" apart.

References Cited UNITED STATES PATENTS 8 FOREIGN PATENTS 206,933 10/1940 Germany 15236 DANIEL BLUM, Primary Examiner US. Cl. X.R.

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