The present application claims the benefit of U. S.

Provisional Application No. 60/301,417, filed June 29, 2001.

BACKGROUND OF THE INVENTION The present invention relates to the application of adhesive to a surface.

When applying adhesive to a surface, for example for installation of ceramic tile or floor coverings, it is common practice to place a quantity of the adhesive on the surface and to then spread the adhesive with a notched trowel in order to create adhesive beads that are spaced apart. This procedure is time-consuming and inefficient, and requires a substantial amount of clean-up work.

BRIEF SUMMARY OF THE INVENTION The present invention provides a novel adhesive dispensing cartridge that is disposable or refillable, and an adhesive applicator composed of the cartridge, a cartridge holder having a receptacle for retaining the cartridge and a movable drive element carried by the holder

and coupled to the cartridge to force adhesive out of the cartridge.

The adhesive dispensing cartridge according to the invention is composed of a housing enclosing a space for containing a quantity of adhesive, the housing having a front end and a rear end, an adhesive delivery element connected at the front end of the housing, the element being composed of a plurality of teeth spaced apart by recesses and being provided with a plurality of adhesive flow passages extending between the space enclosed by the housing and the recesses, and a plate disposed in the space at the rear end of the housing, the plate cooperating with the housing to contain the adhesive and being movable within the housing toward the front end to force adhesive from the space and through the flow passages.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective front view of one embodiment of a cartridge according to the invention.

Figure 2 is view similar to that of figure 1 showing the cartridge of figure 1 provided with a movable protective cap.

Figure 3 is a perspective rear view of the cartridge of figure 1.

Figure 4 is a detail view of one end of a component of the cartridge of figures 1-3.

Figure 5 is a cross-sectional view taken along line V-V of figure 1.

Figure 6 is a detail view of a front portion of an element of the cartridge of figures 1-5.

Figure 7 is a bottom plan detail view of the portion shown in figure 6.

Figure 8 is a perspective view depicting adhesive beads being produced by an applicator according to the invention.

Figure 9 is a simplified side elevational, cross- sectional view of an applicator equipped with a cartridge according to the present invention.

Figure 10 is a top plan view of the applicator shown in figure 9.

Figure 11 is a front perspective view of the applicator.

Figure 12 is an elevational view of one component of the applicator.

Figure 13 is a simplified schematic diagram of a circuit for controlling operation of the applicator.

DETAILED DESCRIPTION OF THE INVENTION A preferred embodiment of a cartridge 10 according to the present invention is shown in figures 1-3. This cartridge is composed essentially of a housing 12 having the general form of a rectangular prism and composed of a front end 16, a rear end 18, an upper side, a lower side (not visible) and two lateral sides. At least two of the sides are each provided with at least one inwardly projecting land 24 that extends between ends 16 and 18.

Front end 16 is provided, along the lower edge thereof, with an adhesive dispensing element 28 formed to present a series of downwardly projecting teeth 30 spaced from one another by recesses 32.

Housing 12 has a hollow interior that is filled with an adhesive to be dispensed and rear end 18 is constituted by a plate that is movable relative to the remainder of housing 12 toward front end 16 so as to force adhesive out of dispensing element 28, as will be described in greater detail below. Thus, plate 18 will function as a primary plunger.

Figure 2, which is a view similar to that of figure 1, shows element 28, covered with a protective cap 34 when cartridge 10 is not in use.

As can be seen in figure 3, plate 18 is provided at its edge with grooves that mate with lands 24.

Figure 4 is a detail view of one end of plate 18, as viewed from within housing 12. According to one optional feature of the invention, plate 18 is provided with a flange 36 that extends around the entire periphery of plate 18 and projects into housing 12. Flange 36 and the grooves that mate with lands 24 cooperate to guide plate 18 so that it remains parallel to front end 16 while being displaced. In addition, flange 36 can be formed to serve as a seal and to prevent plate 18 from backing out of housing 12.

Figure 5 is a cross-sectional view taken along line V-V of figure 1. Figure 5 shows that housing 12 encloses a space, or chamber, 40 containing adhesive to be dispensed.

Element 28 is provided with a plurality of adhesive flow passages 42 each extending between chamber 40 and the base of a respective one of recesses 32.

Further details of dispensing element 28 are shown in figures 6 and 7. Figure 6, in particular, shows that, in a preferred embodiment of the invention, each tooth has a flat bottom surface, while each recess 32 has a rounded bottom.

Figure 7 shows the location of the outlet end of each passage 42 at the base of its respective recess 32.

Figure 8 depicts adhesive beads 46 produced by an applicator according to the invention. In order to produce these beads, it is only necessary to move cartridge 10

rearwardly, i. e., in the direction from front end 16 to rear end 18, while simultaneously displacing plate 18 toward front end 16. As long as the lower surfaces of teeth 30 remain in contact with, or close to, the surface 50 to which the adhesive is to be applied, beads 46 will have cross sections corresponding to those of recesses 32.

Cartridge 10 may be made of any suitable material, such as aluminium, and may be either reusable or disposable.

Figure 9 is a simplified side elevational, cross- sectional view of an applicator equipped with a cartridge 10 according to the present invention. The applicator is a hand- held device having a main housing 60 from which extends a handle 62. The rear end of main housing 60 is provided with a receptacle for a battery 64, which is preferably rechargeable.

The front end of main housing 60 constitutes a cartridge receptacle 66 in which a cartridge 10 will be held when adhesive is to be dispensed. Cartridge 10 and receptacle 66 are dimensioned so that when cartridge 10 is held in place in receptacle 66, the lower surfaces of teeth 30 will be substantially flush with the lower surface of receptacle 66.

Cartridge 10 will be held in place in receptacle 66 by a fastening bar 68 that extends across, and is in contact with, front end 16.

Housing 60 contains an electric drive motor 72 having an output shaft connected to a transmission 74.

Transmission 74 is, in turn, coupled to a bevel gear arrangement that includes an output gear 76. Gear 76 is coupled to cogged, or toothed, drive rod 80. Gear 76 and rod 80 thus form a rack and pinion mechanism. Rod 80 is preferably a solid rod having a square cross section and is guided for longitudinal movement in two guides 86 and 88 that are fixed in housing 60.

The output end of rod 80 carries a secondary plunger 90 that preferably corresponds closely in shape, but is slightly smaller, than plate 18. Rotation of motor 72 thus produces linear movement of rod 80 to advance plunger 90 and plate 18 into cartridge 10, thus forcing adhesive through passages 42 and into recesses 32.

The operation of motor 72 is controlled by a manually operable variable speed trigger switch 92 and a forward/reverse switch 94 in handle 62. Trigger switch 92 is coupled to battery 64 and motor 72 in order to cause the speed of motor 72 to vary as a function of the degree of depression of trigger 92. Circuitry for performing such an operation is already well known in the art. The output shaft of motor 72 may also carry a fan 98 that will produce a flow of air for cooling motor 72.

Figure 10 is a top plan view of the applicator shown in figure 9 and shows bar 68 pivotally mounted to a hinge 102.

The free end of bar 68 engages a latch 104 that holds bar 68 in a closed position when the applicator is in use.

Figure 11 is a front perspective view of the applicator, with no cartridge being provided in receptacle 66.

Housing 60 is provided with a series of vents 106 that provide ventilating airflow. There may be three such vents along each side of housing 60.

Figure. 12 shows one example of latch 104, which is composed essentially of a mounting plate 110, tension spring clips 112 and clip release levers 114. When clips 112 are in their normal position, as shown in Figure 12, bar 68 is held in a closed condition. In order to release bar 68, for example in order to replace a cartridge 10, the user deflects levers 114 toward the rear, thus moving clips 112 away from one another.

Figure 13 is a simplified schematic diagram illustrating the connection of battery 64 to motor 72 via trigger 92. Trigger 92 is coupled to conventional control circuitry 120 that will vary the power supplied to motor 72 as a function of the degree of depression of trigger 92. By way of non-limiting example, circuitry 120 could include a simple potentiometer that varies the magnitude of the voltage

supplied to battery 72, or could be a SCR control circuit that varies the rate of application of drive voltage pulses to motor 72. Those skilled in the art will be readily aware of other types of control circuits that can be employed. Control circuit 120 can be coupled in a suitable manner to switch 94 to allow for control of the direction of rotation of motor 72.

In order to dispense adhesive with the applicator according to the present invention, it is only necessary for the user to rest the bottoms of teeth 30 on the work surface and place motor 72 into operation while drawing the applicator rearwardly along the surface and controlling the speed of motor 72 in order to coordinate the rate at which adhesive is dispensed with the rate of displacement of the applicator.

The application of beads to the work surface may be improved if the applicator is held at a slight angle to the work surface such that the leading edge, i. e., the edge furthest from front end 16, of the teeth are in contact with the surface and the bottom surfaces of the teeth form an angle of the order 5° with the work surface.

When the supply of adhesive in a cartridge has been exhausted, it is only necessary to replace the cartridge in order to continue adhesive application. The empty cartridge may be thrown away, since it is a relatively inexpensive component.

If, at the end of an adhesive application task, useable adhesive remains in the cartridge, cap 34 may be placed over element 28 in order to prevent accidental escape of adhesive and maintain the adhesive in a condition for future use. Cap 34 could be configured to additionally engage the rear edge of element 28 in order to completely seal the spaces defined by recesses 32.

The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without undue experimentation and without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. The means, materials, and steps for carrying out various disclosed functions may take a variety of alternative forms without departing from the' invention.

Thus the expressions"means to..."and"means for...", or any method step language, as may be found in the specification above and/or in the claims below, followed by a

functional statement, are intended to define and cover whatever structural, physical, chemical or electrical element or structure, or whatever method step, which may now or in the future exist which carries out the recited function, whether or not precisely equivalent to the embodiment or embodiments disclosed in the specification above, i. e. , other means or steps for carrying out the same functions can be used; and it is intended that such expressions be given their broadest interpretation.