Dosage control for adhesive dispenser

Abstract: A pneumatically actuatable dispenser for a two-part adhesive, as provided in a cartridge (12) having two chambers (14) and having a mixing nozzle (16) mounted to a first end, each chamber having a plunger accessible from a second end. A front frame (30) holds the cartridge (12). A piston is arranged to be selectively driven within a cylinder (52) in a forward or reverse direction. A pair of piston rods (7) operate in tandem to drive the plungers toward the nozzle (16), when driven conjointly with the piston in the forward direction. A first valve, when actuated, delivers pressurized air driving the piston in the forward direction. A second valve, when actuated, delivers pressurized air driving the piston oppositely. A third valve, when actuated while the first valve is actuated, vents pressurized air from the cylinder (52). A first control rod, which moves conjointly with the piston, and a second control rod (114) may be selectively linked to each other for conjoint movement or unlinked from each other, via a linking lever (140) and a cam (150). An actuator (118), which is positionable adjustably along the second control rod, actuates the third valve after conjoint movement of both control rods and the actuator, along with the piston, by a distance correlating to a controlled dose of the mixed parts of the adhesive. A valve (86) can be manually actuated to divert pressurized air, via a hose, to a nozzle for blowing water or debris from a hole to receive the adhesive.

Description: This invention pertains to an improved, pneumatically-actuated dispenser for an adhesive, such as a two-part epoxy adhesive. This invention provides dosage control for the adhesive dispenser. Two-part adhesives, such as two-part epoxy adhesives, are used widely, in large doses at construction sites and elsewhere, particularly but not exclusively to set studs, anchors, and other hardware into holes bored or formed otherwise in concrete or masonry. Such adhesives are available commercially in two-chamber cartridges, which fit into various manually-actuated or pneumatically-actuated dispensers. A commercial source for such adhesives in such cartridges, for such manually-actuated dispensers, and for such pneumatically-actuated dispensers is ITW Ramset/Red Head (a division of Illinois Tool Works Inc.) of Wood Dale, Illinois. Even at a construction site where large doses of such adhesives are used, a single dose may not use all contents of such a cartridge, which may contain enough of such adhesive, or of each part of such adhesive, to provide two, three, or more doses. It is known to provide a visible scale, on an exposed surface of such a cartridge, as a way to measure each such dose. When using a manually actuated or pneumatically actuated dispenser, it has been necessary heretofore for the user to judge visually, as by movement of a rod of the dispenser vis-a-vis such a scale if provided, when each dose has been dispensed. Commonly, moreover, it has been necessary for the user to estimate when a sufficient dose has been injected into a hole. More particularly, the instant invention relates to a pneumatically actuated dispenser for an adhesive, as provided in a cartridge having a chamber containing the adhesive, the cartridge having a first end and a second end and having a nozzle mounted to the first end, the chamber having a plunger accessible from the second end and displaceable through the chamber, toward the nozzle, so as to force the adhesive into the nozzle, through which the adhesive is injected, the dispenser comprising: a frame adapted to hold such a cartridge; a pneumatic machanism connectable to a source of pressurized air and attached to the frame so as to support the frame with such a cartridge held by the frame, the pneumatic mechanism comprising: a pneumatic cylinder affixed to the frame; pneumatic piston means arranged to be pneumatically driven within the cylinder by the pressurized air, pneumatic control means for selectively driving the pneumatic piston means in said pneumatic cylinder in a forward direction or in a reverse direction by said pressurized air; a piston rod extended from the pneumatic piston means, through one end of the pneumatic cylinder, and arranged to move conjointly with the pneumatic piston means, to drive the plunger of such a cartridge held by the frame toward the nozzle when the pneumatic piston means is driven in a forward direction, and to withdraw from the plunger of the last-mentioned cartridge when the pneumatic piston means is driven in the reverse direction. Such a dispenser is, for instance, tought by EP-A-0276665. However, this dispenser does not solve any dosage control problem. It just proposes, considering an adhesive with two parts of different viscosities, a solution to the problem of the tilting or jamming of the piston means. Consequentally, there has been a need, to which this invention is addressed, for a better way to achieve dosage control with a pneumatically actuated dispenser for an adhesive, particularly but not exclusively a two-part adhesive, such as a two-part epoxy adhesive. FR-A-984352 teaches a dispenser comprising dosage control means. However, the dispenser of this document is a manually actuated tool with no pneumatic mechanism, no control means, and just having a biased plunger for being operated as a pump, first, prior to dispensing a pumped liquid to an animal. The instant invention, accordingly, provides a pneumatically actuatable dispenser of the above mentioned type, characterized by the fact that said pneumatic mechanism further comprises means predeterminedly adjustable by a user and operatively connected to said piston means for actuating said pneumatic control means so as to predeterminedly limit conjoint movement of the pneumatic piston means and the piston rod in the forward direction beyond a predetermined amount of travel of said pneumatic piston means and said piston rod so as to enable the dispenser to inject an adjustably controlled dose of an adhesive from such a cartridge held by the frame. Although the improved dispenser provided by this invention is useful for a single-part adhesive, as provided in such a cartridge having a single chamber, or for a several-part adhesive, as provided in such a cartridge having several chambers, the improved dispenser provided by this invention has particular utility for a two-part adhesive, as provided in such a cartridge having two chambers. In such a cartridge having two chambers, each chamber contains one of two parts of the adhesive, and the cartridge has a mixing nozzle, which is mounted to a first end of the cartridge, and which is arranged to receive one of the parts of the adhesive from each chamber and to mix such parts. Moreover, each chamber has a plunger, which is accessible from a second end of the cartridge, and which is displaceable through such chamber, toward the nozzle, in which the parts of the adhesive are mixed, and through which the mixed parts of the adhesive are injected. The pneumatic mechanism comprises a piston rod for each cartridge chamber. If one piston rod is used for such a cartridge having a single chamber, the piston rod is arranged to drive the plunger of the cartridge toward the nozzle of the cartridge when the pneumatic piston is driven in a forward direction and to withdraw from the plunger when the pneumatic piston is driven in a reverse direction. If a pair of piston rods are used for such a cartridge having two chambers, each piston rod is arranged to drive the plunger of a respective one of the chambers toward the nozzle of the cartridge when the pneumatic piston is driven in a forward direction and to withdraw from the same plunger when the pneumatic piston is driven in a reverse direction. In a preferred embodiment of this invention the pneumatic control means comprise pneumatic valves including a manually actuatable first valve arranged, when actuated manually with the pneumatic mechanism connected to the source of pressurized air, to deliver pressurized air from the source to the pneumatic cylinder so as to drive the pneumatic piston means in the forward direction; a manually actuatable second valve arranged, when actuated manually with the pneumatic mechanism connected to the source of pressurized air, to deliver pressurized air from the source to the pneumatic cylinder so as to drive the pneumatic piston means in the reverse direction; and a mechanically actuatable third valve arranged, when actuated mechanically while the first valve is actuated, to block pressurized air from flowing from the first valve into the pneumatic cylinder and simultaneously to vent pressurized air, as delivered previously by the first valve, from the pneumatic cylinder to ambient atmosphere. Still preferably, the predeterminedly adjustable means comprise a first control rod arranged to be conjointly driven with the pneumatic piston means, along an exterior surface of such a cartridge held by the frame, without interfering with the last-mentioned cartridge; a second control rod arranged to be selectively linked to or unlinked from the first control rod so as to move conjointly with the first control rod, in parallel relation to the first control rod, when linked to the first control rod, and so as to be independently movable when unlinked from the first control rod; means operable manually and selectively by a user to link the second control rod to the first control rod, at any position within a range of possible positions along the first control rod, or to unlink the second control rod from the first control rod; an actuator positionable adjustably along the second control rod, at any position within a range of possible positions along the second control rod, for conjoint movement with the second control rod, the actuator being arranged to actuate the third valve upon conjoint movement of the first control rod, the second control rod, and the actuator from respective dose-initiating positions relative to the pneumatic cylinder, where the piston rod can begin to drive the plunger of such a cartridge held by the frame toward the nozzle of the last-mentioned cartridge, to respective dose-concluding positions relative to the pneumatic cylinder, where the plunger of the last-mentioned cartridge has been displaced by a distance correlating to a controlled dose of the adhesive from the last-mentioned cartridge; whereby the actuator can be adjustably positioned along the second control rod so as to enable the dispenser, when the second rod is linked to the first control rod, to inject a controlled dose of an adhesive from such a cartridge held by the frame with the last-mentioned dose being less than full contents of the last-mentioned cartridge. Preferably, the means described in the preceding sentence comprise a linking lever, which is attached to one end of the second control rod so as to retain the linking lever on the end of the second control rod but to permit a limited range of pivotal movement of the linking lever on the end of the second control rod. The linking lever has an aperture, through which the first control rod extends with a loose fit allowing the first control rod to pass freely through the aperture except when pivotal movement of the linking lever causes the linking lever frictionally to engage the first control rod. Coacting means are provided, namely means for basing the second control rod in the reverse direction and means operable manually by a user to position the linking lever selectively in a pivotal position permitting the first control rod to pass freely through the aperture or in a pivotal position causing the linking lever frictionally to engage the first control rod as mentioned. Preferably, the means operable manually by a user to position the linking lever comprises a cam, which is mounted operatively, more preferably on the pneumatic cylinder or less preferably to the linking lever, and which is arranged to be manually adjusted between a condition wherein the cam engages and is interposed between the linking lever and adjacent structure so as to position the linking lever in the pivotal position permitting the first control rod to pass freely through the aperture and a condition wherein the cam permits the means for biasing the second control rod in the rearward direction to pivot the linking lever, via the second control rod, to a pivotal position causing the linking lever frictionally to engage the first control rod as mentioned. The actuator mentioned above is positionable adjustably along the second control rod, at any position within a range of possible positions along the second control, for conjoint movement with the second control rod. Also, the actuator is arranged to actuate the third valve (so as to block pressurized air from flowing from the first valve into the pneumatic cylinder and simultaneously to vent pressurized air, as delivered previously by the first valve, from the pneumatic cylinder) upon conjoint movement of the first control rod, the second control rod, and the actuator from respective dose-initiating positions relative to the pneumatic cylinder to respective dose-concluding positions relative thereto. When the first control rod, the second control rod, and the actuator are in their dose-initiating positions, the piston rod, or piston rods, can begin to drive the plunger, or plungers, of such a cartridge held by the frame toward the nozzle of the cartridge. When the first control rod, the second control rod, and the actuator are in their dose-concluding positions, the plunger, or plungers, of such a cartridge has, or have, been displaced by a distance correlating to a controlled dose of adhesive, or of the mixed parts of an adhesive, from the cartridge. The actuator mentioned above can be adjustably positioned along the second control rod so as to enable the dispenser, when the second control rod is linked to the first control rod, to dispense a control dosage of an adhesive, or of the mixed parts of an adhesive, from such a cartridge held by the frame with such dose being less than full contents of such cartridge, e.g., with such dose being one-third of such contents. Because of this invention, there is no need for a user to judge visually when each dose has been injected or to estimate when a sufficient dose has been injected into a hole. Such visual judgments and such estimates can be oftentimes impossible because of application conditions. Moreover, the pneumatic mechanism may comprise a manually actuatable fourth valve, which is arranged, when actuated with the pneumatic mechanism connected to the source of pressurized air, to divert pressurized air entering the pneumatic mechanism, along with a hose connected to the fourth valve and, preferably, a nozzle connected to the hose. The fourth valve and the hose, either with or without the nozzle connected to the hose, can be advantageously used to blow water, debris, or both from a hole bored or formed otherwise in concrete or masonry, just before an adhesive is dispensed into the hole. A similar arrangement of such a valve and a hose, either with or without a nozzle connected to the hose, can be advantageously used, in like manner, in any pneumatically actuatable dispenser for an adhesive, as provided in such a cartridge, if the dispenser comprises a frame, which is adapted to hold the cartridge, and a pneumatic mechanism, which is connectable to a source of pressurized air, which is attached to the frame, and which is operable to dispense an adhesive from such a cartridge held by the frame. These and other objects, features, and advantages of this invention are evident from the following description of a preferred embodiment of this invention, with reference to the accompanying drawings. FIGURE 1 is a partly fragmentary, partly exploded, perspective view of an improved, pneumatically-actuated, adhesive dispenser constituting a preferred embodiment of this invention, along with a two-chamber cartridge containing a two-part adhesives. FIGURE 2 is a partly fragmentary, perspective view of a cover used in the adhesive dispenser. An adjustable actuator used therein appears beneath a slot in the cover, which is shown as bearing visible indicia. FIGURE 3 is a partly fragmentary, perspective view of the adhesive dispenser. As compared to FIGURE 1, FIGURE 3 is taken from a different vantage point. FIGURE 4 is a fragmentary view taken substantially in axial cross-section to shown an actuator for a valve used in the adhesive dispenser. FIGURE 5 is a partly fragementary, elevational view taken from one side, partly in cross-section, to show certain details of the adhesive dispenser. A front frame shown in FIGURE 1 is omitted in FIGURE 5. FIGURE 6 is a fragementary detail of certain elements shown in FIGURE 5, but with a linking lever shown in cross-section and in a changed position, and with a cam shown in a changed position. FIGURE 7 is a greatly enlarged, fragmentary detail of the linking lever and a first control rod, with which the linking lever coacts. FIGURES 8, 9, and 10 are partly fragmentary, elevational views of the adhesive injector, with certain elements shown in different positions in phantom and full lines respectively to illustrate sequential operations of the adhesive dispenser. FIGURE 11 is a conceptual layout of pneumatic controls and pneumatic lines, as used in the adhesive dispenser. FIGURE 12 is a circuit diagram of pneumatic controls and pneumatic lines, as shown in FIGURE 11. FIGURE 13 is a fragmentary, perspective detail of one end of the link and a cam substitutable for the cam shown in other views, described above, in an alternative embodiment of this invention. FIGURES 14 and 15 are fragmentary details similar to FIGURE 6, but with the cam shown in FIGURE 13. The linking levers and the cam are shown in different positions in FIGURES 14 and 15 respectively. As shown in FIGURES 1 through 12, a pneumatically actuated dispenser 10 for a two-part adhesive, such as a two-part epoxy adhesive, as a provided in a cartridge 12 constituting a preferred embodiment of this invention. The cartridge 12, which appears in FIGURE 1 and also in FIGURES 8, 9, and 10, is an example of cartridges with which the dispenser 10 is useful. The cartridge 12 has two chambers 14, which are tubular with circular cross-sections, and a replaceable mixing nozzle 16, which is attached at a first or front end of the cartridge 12 by a threaded connector 18, and which has an elongate tip, as shown in FIGURES 8, 9, and 10. Each chamber 14 contains one part of the adhesive, typically but not necessarily in gel, paste, semi-liquid, or high viscosity liquid form, and has a plunger 20 (one shown; see FIGURES 8 through 10) which seals each adhesive part within its cartridge chamber, and which is accessible from a second or back end of the cartridge 12, and which is displaceable through such chamber 14, toward the nozzle 16. The nozzle 16 is arranged to receive one part of the adhesive from each chamber 14, to mix the parts of the adhesive, and to inject the mixed parts of the adhesive, as into a hole (not shown) bored or formed otherwise in concrete or masonry, just after water and debris have been blown from the hole in a manner to be later described. The adhesive may be thus used to set a stud, anchor, or other hardware (not shown) in the hole. The cartridge 12 is formed with a longitudinal valley 22, which extends along its upper, exterior surface. Such cartridges containing two-part epoxy adhesives are available commercially from ITW Ramset/Red Head (a division of Illinois Tool Works Inc.) of Wood Dale, Illinois. Generally, the injector 10 comprises a front frame, which is adapted to hold a cartridge exemplified by the cartridge 12, and a pneumatic mechanism, which is attached to the front frame so as to support the front frame with the cartridge held by the front frame. As shown in FIGURES 1 and 3, the front frame 30 comprises a cradle 32, which is fabricated from sheet steel, and which fits under and partially around the nozzle 16, so as to limit axial movement of the connector 18 when the connector 18 is threaded onto the cartridge 12, and a wire bracket 34, which is fabricated from steel wire, and which has a bight 36 adapted to fit under a front portion of a cartridge exemplified by the cartridge 12. The wire bracket 34, which is welded to the cradle 32 at spaced locations near the bight 36, is secured at its opposite ends 38 to the pneumatic mechanism, via a mounting plate 40, which is mounted integrally to a front surface of a lower mounting block 42. The pneumatic mechanism 50 comprises a pneumatic cylinder 52, a handle 54 extending downwardly from the lower mounting block 42, and a handle 56 extending laterally from the lower mounting block 42, and is connectable to a source 58 of pressurized air, under regulated pressure, such as an air compressor, which is preferred, or an air cylinder. The source 58 is represented diagrammatically in FIGURE 12. The pneumatic mechanism 50 is connectable to the source 58 of pressurized air, via a conventional fitting 60, which is provided at a lower end of the downwardly extending handle 54, and a flexible pneumatic line 62, which is shown fragmentarily in FIGURE 1, and diagrammatically in FIGURES 11 and 12, and a pressure regulator 64, which is shown diagrammatically in FIGURE 12. A double-acting pneumatic piston 70 (see FIGURES 8 through 12) is arranged, in a conventional manner, to be pneumatically driven within the pneumatic cylinder 52, selectively in a forward direction or in a reverse direction. Two piston rods 72 are provided, which operate in tandem, one for each chamber of a cartridge like the cartridge 12. Each piston rod 72 extends through a suitably sealed aperture in a front end of the pneumatic cylinder 52, and through suitable apertures in the lower mounting block 42 and in the mounting plate 40, and is provided at its distal end with an enlarged boss 74, on which is mounted a plunger-engaging element 76 made of synthetic rubber or equivalent material. Each piston rod 72 is arranged, via the plunger-engaging element 76 mounted on the enlarged boss 74 on the distal end of such piston rod 72, to drive the plunger 20 of a respective one of the chambers of a cartridge exemplified by the cartridge 12, as held by the front frame 30, when the pneumatic piston 70 is driven in a forward direction and to withdraw from the same plunger when the pneumatic piston 70 is driven oppositely, i.e., in a reverse direction. The enlarged bosses 74 and the plunger-engaging elements 76 conform approximately, in outer diameter, to the plungers of such a cartridge, e.g., the plungers 20. The pneumatic mechanism 50 comprises several pneumatic valves, namely a manually actuatable first valve 80, a manually actuatable second valve 82, a mechanically actuatable third valve 84, and a manually actuatable fourth valve 86, each as represented diagrammatically in FIGURES 11 and 12. The first valve 80 is mounted in the downwardly extending handle 54, so as to be manually actuatable via an external button 92 carried on a stem 94 (see FIGURE 12) of the first valve 80. The second valve 82 is mounted in the laterally extending handle 56 so as to be manually actuatable via an external button 96 carried on a stem 98 (see FIGURE 12) of the second valve 82. The third valve 84 is mounted on the pneumatic cylinder 52 so as to be mechanically actuatable in a manner to be later described. The fourth valve 86 is mounted in the downwardly extending handle 54, beneath the first valve 80, so as to be manually actuatable via an external button 102 carried on a stem 104 (see FIGURE 12) of the fourth valve 86. The first valve 83 is arranged, when actuated with the pneumatic mechanism 50 connected to the source 58 of pressurized air, to deliver pressurized air from the source 58 to the pneumatic cylinder 52 so as to drive the pneumatic piston 70 in the forward direction. The second valve 82 is arranged, when actuated with the pneumatic mechanism 50 connected to the source 58 of pressurized air, to deliver pressurized air from the source 58 to the pneumatic cylinder 52 so as to drive the pneumatic piston 70 in the reverse direction. Pneumatic lines connected to and from the first valve 80 and pneumatic lines connected to and from the second valve 82 are represented diagrammatically in FIGURES 11 and 12. If the first valve 80 and the second valve 82 should be simultaneously actuated with the pneumatic mechanism 50 connected to the source of pressurized air, the pneumatic piston 70 would stall and would not be pneumatically driven in either direction. The third valve 84 is arranged, when actuated while the first valve 80 is actuated, to block pressurized air from flowing from the first valve 80 into the pneumatic cylinder 52 and simultaneously to vent pressurized air, as delivered previously by the first valve 80, from the pneumatic cylinder 52, through the third valve 84 and through a port 106 (see FIGURE 1) to ambient atmosphere, whereby the pneumatic piston 70 tends to be immediately arrested. If each part of an adhesive provided in a cartridge exemplified by the cartridge 12 is provided in gel, paste, semi-liquid, or high viscosity liquid form, as mentioned above, inertial movement of the pneumatic piston 70 tends to be very insignificant. Means 110 are provided for limiting conjoint movement of the pneumatic piston 70 and the piston rods 72 in the forward direction, so as to enable the dispenser 10 to dispense an adjustably controlled dose of the mixed parts of an adhesive from a cartridge exemplified by the cartridge 12, as held by the front frame 30. The means 110, which are adjustable by a user, are provided by a first control rod 112, a second control rod 114, means 116 operable manually and selectively by a user for certain purposes described below, and an actuator 118 for the third valve 84. See FIGURES 1 and 8, 9, and 10. The first control rod 112 extends through a suitably sealed aperture in the front end of the pneumatic cylinder 52, and through suitable apertures in the lower mounting block 42 and in the mounting plate 40, and is arranged to be conjointly driven with the pneumatic piston 70, along an upper, exterior surface of a cartridge exemplified by the cartridge 12, as held by the front frame 30, and along a longitudinal valley exemplified by the valley 22 of the cartridge 12. If the cartridge bears a visible scale (not shown) on its upper, exterior surface, a user can judge visually, by movement of the first control rod 112 vis-a-vis the scale, movement of the pneumatic piston 70, conjointly with the first control rod 112, as in adhesive dispensers as known heretofore. The second control rod 114 is arranged to be selectively linked to or unlinked from the first control rod 112 so as to remove conjointly with the first control rod 112, in parallel relation to the first control rod 112, when linked to the first control rod 112, and so as to be independently movable when unlinked from the first control rod 112. The second control rod 114 is mounted for axial movement, in the forward direction and in the reverse direction, by an upper mounting block 120, which is mounted integrally on the lower mounting block 42, and which has a suitable aperture for the second control rod 114, and by a mounting strap 122, which extends rearwardly from the upper mounting block 120, and which has a bent end 124 having a suitable aperture for the second control rod 114. A rearmost end 126 of the second control rod 114 is threaded. A cap nut 128 is threaded onto the threaded end 126. A coiled spring 130, which is deployed around the second control rod 114, between the bent end 124 of the mounting strap 122 and the cap nut 128, biases the second control rod 114 in the rearward direction. The means 116 mentioned above as operable manually and selectively by a user prevent the second control rod 114, as biased by the coiled spring 130, from being pulled through the upper mounting block 120. Such means 116 comprise a linking lever 140 having an aperture 142, through which the first control rod 112 passes with sufficient clearance to permit the linking lever 140 to pivot from a position at a right angle to the first control rod 112 through an angle as large as about 10° relative to the first control rod 112, and an aperture 144, through which the second control rod 114 passes with sufficient clearance to permit the linking lever 140 to pivot through a similar angle relative to the second control rod 114, i.e., through an angle as large as about 10° relative to the second control rod 114. The adjacent end 146 of the second control rod 114 is fitted with a retaining clip 148, which prevents the second control rod 114, as biased by the coil spring 130, from being pulled through the aperture 144 in the linking lever 140. The upper mounting block 120 is offset on the lower mounting block 42, as shown in FIGURES 1, 5, and 6. Such means 116 also comprise a cam 150, which is mounted to the upper mounting block 120, via a vertical pin 152, for free rotation in either rotational sense about a vertical axis defined by the vertical pin 152, and which is cylindrical, except for a flat surface 154 truncating its cylindrical periphery, and except for knurling on its cylindrical periphery. The cam 150 engages and is interposed between upper portions of the linking lever 140 and adjacent structure provided by the upper mounting block 120, so as to position upper portions of the linking lever 140 away from the upper mounting block 120 when lower portions of the linking lever 140 bear against the lower mounting block 42, unless the cam 150 is rotated so that the flat surface 154 faces and engages the linking lever 140. If the cam 150 is rotated so that the flat surface 154 faces and engages the linking lever 140, the linking lever 140 is permitted to pivot, as biased by the coiled spring 130 biasing the second control rod 114, from a position at a right angle to the first control rod 112 through the aforesaid angles (as large as about 10°) relative to the first control rod 112 and the second control rod 114 respectively. When the linking lever 140 is pivoted to the aforesaid angles relative to the first control rod 112 and the second control rod 114 respectively, frictional engagement between the linking lever 140 and the first control rod 112, at two points located respectively at opposite upper and lower portions of the margins of the aperture 142, and causes the linking lever 140 to link the second control rod 114 to the first control rod 112. Similar engagement can but does not have to occur between the linking lever 140 and the second control rod 114 at opposite upper and lower portions of the margins of the aperture 144. The retaining clip 148 causes the second control rod 114 to move conjointly with the linking lever 140 in a forward direction. However, when the linking lever 140 is disposed at right angles relative to the first control rod 112 and the second control rod 114 respectively, the first control rod 112 and the second control rod 114 are unlinked from each other, as occurs when the linking lever 140 is in a home position wherein the cam 152 (but not the flat surface 154) engages the linking lever 140 or when the linking lever 140 (in or away from the home position) is actuted manually. The actuator 118 comprises a block 158 having a suitable aperture, through which the second control rod 114 passes, and a thumb screw 160, which has a threaded shank 162. The thumb screw 160 can be manually loosened, so as to permit the actuator 118 to be adjustably positioned along the second control rod 114, and can be manually tightened, so as to secure the actuator 118 in a selected position along the second control rod 114. The actuator 118 can be adjustably positioned within a range of possible positions along the second control rod 114. The range is defined by a retaining clip 164, which is mounted in an annular groove on the second control rod 114, and by the third valve 84. See FIGURE 1. The actuator 118 is arranged to actuate the third valve 84 in a manner described below (so as to block pressurized air from flowing from the first valve 80 into the pneumatic cylinder 52 and simultaneously to vent pressurized air, as delivered previously by the first valve 80, from the pneumatic cylinder 52) upon conjoint movement of the first control rod 112, the second control rod 114, and the actuator 118 from respective dose-initiating positions relative to the pneumatic cylinder 52 (see e.g., FIGURE 9) where the piston rod 72 can begin (via the enlarged bosses 74 and the plunger-engaging elements 76) to drive the plungers of a cartridge exemplified by the cartridge 12, as held by the front frame 30, toward the nozzle of the cartridge to respective dose-concluding positions relative to the pneumatic cylinder 52 (see, e.g., FIGURE 10) where the plungers of the cartridge have been displaced by a distance correlating to a controlled dose of the mixed parts of an adhesive from the cartridge. After a dose of the mixed parts of adhesive from a cartridge exemplified by the cartridge 12 has been dispensed by the dispenser 10 (see, e.g., FIGURE 8) the linking lever 140 must be manually pivoted so as to assume right angles relative to the first control rod 112 and the second control rod 114 respectively (see, e.g., FIGURE 9 wherein the linking lever 140 is shown, in phantom lines, at right angles relative thereto) whereupon the coiled spring 130 can pull the linking lever 140, via the second control rod 114, in the rearward direction until lower portions of the linking lever 140 engage the lower mounting block 42, at the home position noted above. If a next dose is to be then dispensed from the same cartridge, the cam 150 must remain rotated (or be again rotated) so that the flat surface 154 faces and engages the linking lever 140, whereby the linking lever 140 again links the first control rod 112 and the second control rod 114 to each other. A cover 170, which has an elongate slot 172 for the threaded shank 162 of the thumb screw 160, and which has an aperture for the vertical pin 152 mounting the cam 150, is bolted onto the upper mounting block 120. The cover 170 covers the third valve 84, as a precaution against accidental or deliberate actuation of the third valve 84 by a user during injection of a dose, and covers the second control rod 114, the upper mounting block 120, the mounting strap 122, and the coiled spring 130, as a precaution against the user pinching his or her fingers. As shown in FIGURE 2, the cover 170 is provided with visible indicia 180, to which a user can refer when positioning the actuator 118, via the thumb screw 160, along the second control rod 114. As shown in FIGURE 4, means 180 are provided for ensuring rapid actuation of the third valve 84 by the actuator 118. The third valve 84 has an external stem 182, which is used to actuate the third valve 84, and which is biased outwardly. The block 158 of the actuator 118, however, does not directly engage the external stem 182. Such means 180 comprise a stepped, tubular structure 184, which is mounted to the third valve 84, over the stem 182, via a bracket 186 and a nut 188, which is threaded onto a threaded portion 190 of the structure 184, as shown. A spool 192, which is movable axially within the tubular structure 184, is biased toward the stem 182 by a coiled spring 194. A pair of detent balls 196, which are biased, in radially inward directions, by a pair of coiled springs 198, which are held by set screws 200, coact with an annular groove 202 in the spool 192 so as to retain the spool 192 in a position where the spool 192 bears against the stem 182, but where the spool 192 does not displace the outwardly biased stem 182 by any significant amount. The spring 194 is deployed within the tubular structure 184, between the spool 192 and a button 204, which has an external stem 206, and which is retained within the tubular structure 184 (except for the external stem 206) by a cap 208 having a suitable aperture for the external stem 206. The spring 194 biases the stem 206 outwardly. The block 158 of the actuator 118 is arranged to engage the outwardly biased stem 206 of the button 204, upon conjoint movement of the actuator 118 with the second control rod 114 over a distance approaching a distance correlating to a control dose, whereupon the button 204 is displaced so as to compress the coiled spring 194. When the button 204 engages the spool 192, the button 204 upon further movement dislodges the spool 192, so as to cam the balls 196 from the annular groove 202, onto the cylindrical surface of the spool 192, whereupon the spool 192 displaces the outwardly biased stem 182, so as to actuate the third valve 84 with a snap-action. The snap-action assures that the third valve 84 performs its desired functions and averts a situation wherein the first and second valves tend to be simultaneously open to air flow. When the actuator 118 is moved back, i,e., in the reverse direction, the spool 192, the detent balls 196, the coiled spring 194, and the button 204 are returned by the outwardly biased stem 182, which bears against the spool 192, to the positions wherein they appear in FIGURE 4. Internal details of the fourth valve 86 are shown in FIGURE 5. A ball 210, which serves as a valve closure, is biased against a valve seat 212 by a coiled spring 214. A rounded button 216, which is carried integrally at an inner end of the stem 104, prevents the stem 104 from being pulled out of the valve 86. When the button 102 on the stem 104 is depressed manually, the button 216 cams the ball 210 from the seat 212, whereby pressurized air entering the pneumatic mechanism 50 from the source 58 is diverted so as to exit through the seat 212. A hose 218 is connected to the valve 86, via a conventional coupling 220, so as to receive pressurized air exiting through the seat 212. When the button 102 is released, the spring 214 returns the ball 210 onto the seat 212, and the ball 210 cams the button 216 so as to express the stem 104 and the button 102 as far as the button 216 permits. A nozzle 222 is connected to the hose 218. When the button 102 is depressed manually, whereby the fourth valve 86 is actuated, pressurized air passing through the hose 218, to the nozzle 222, can be readily directed by a user so as to blow water, debris, or both from a hole (not shown) bored of formed otherwise in concrete or masonry, just before the mixed parts of an adhesive are injected into the hole by the adhesive dispenser 10. This is done to maximize the bonding capability of the adhesive in an anchoring application. As shown in FIGURES 13, 14, and 15, a cam 230 mounted rotatably on an upper portion of the linking lever 140, as by a threaded pin 232 receiving a nut 234, may be alternatively substituted for the cam 150 mounted on the upper mounting block 120 by the vertical pin 152. The cam 230 is selected so as to have a thickness equal approximately to the distance by which the upper mounting block 120 is offset on the lower mounting block 42. The cam 230 is cylindrical, except for a flat surface 236, on its cylindrical periphery, and except for knurling on its cylindrical periphery. The flat surface 236 enables the cam 230 to clear the cover 170 (see FIGURE 14) when it is desired to allow the linking lever 140 to pivot from a position at a right angle to the first control rod 112 through the aforesaid (non-right) angles (as large as about 10°) relative to the first control rod 112 and the second control rod 114 respectively. The cam 230 engages and is interposed between the linking lever 140 and adjacent structure provided by the upper mounting block 120 (see FIGURE 15) when it is desired to position the linking lever 140 at right angles relative to the first control rod 112 and the second control rod 114 respectively. Herein, directional terms, e.g., "downwardly", and "laterally", upper", "lower", and terms of like import, refer to the dispenser 10 in a convenient orientation, in which the dispenser 10 appears in FIGURE 1 and other views of the drawings, but are not intended to limit the dispenser provided by this invention to any particular orientation.

Claims: A pneumatically actuated dispenser for an adhesive, as provided in a cartridge (12) having a chamber (14) containing the adhesive, the cartridge having a first end and a second end and having a nozzle (16) mounted to the first end, the chamber (14) having a plunger (20) accessible from the second end and displaceable through the chamber, toward the nozzle, so as to force the adhesive into the nozzle, through which the adhesive is injected, the dispenser comprising: a frame (30) adapted to hold such a cartridge; a pneumatic machanism (50) connectable to a source (58) of pressurized air and attached to the frame so as to support the frame with such a cartridge held by the frame, the pneumatic mechanism comprising: a pneumatic cylinder (52) affixed to the frame; pneumatic piston means (70) arranged to be pneumatically driven within the cylinder by the pressurized air, pneumatic control means (80,82,84,86) for selectively driving the pneumatic piston means (70) in said pneumatic cylinder in a forward direction or in a reverse direction by said pressurized air; a piston rod (72) extended from the pneumatic piston means (70), through one end of the pneumatic cylinder (52), and arranged to move conjointly with the pneumatic piston means (70), to drive the plunger (20) of such a cartridge held by the frame toward the nozzle when the pneumatic piston means (70) is driven in a forward direction, and to withdraw from the plunger of the last-mentioned cartridge when the pneumatic piston means (70) is driven in the reverse direction; dispenser characterized by the fact that said pneumatic mechanism (50) further comprises means (110) predeterminedly adjustable by a user and operatively connected to said piston means (70) for actuating said pneumatic control means (80,82,84,86) so as to predeterminedly limit conjoint movement of the pneumatic piston means (70) and the piston rod (72) in the forward direction beyond a predetermined amount of travel of said pneumatic piston means and said piston rod so as to enable the dispenser to inject an adjustably controlled dose of an adhesive from such a cartridge held by the frame. The dispenser of claim 1, wherein said pneumatic control means comprise pneumatic valves including a manually actuatable first valve (80) arranged, when actuated manually with the pneumatic mechanism (50) connected to the source (58) of pressurized air, to deliver pressurized air from the source (58) to the pneumatic cylinder (52) so as to drive the pneumatic piston means (70) in the forward direction; a manually actuatable second valve (82) arranged, when actuated manually with the pneumatic mechanism (50) connected to the source (58) of pressurized air, to deliver pressurized air from the source (58) to the pneumatic cylinder (52) so as to drive the pneumatic piston means (70) in the reverse direction; and a mechanically actuatable third valve (84) arranged, when actuated mechanically while the first valve (80) is actuated, to block pressurized air from flowing from the first valve (80) into the pneumatic cylinder (52) and simultaneously to vent pressurized air, as delivered previously by the first valve (80), from the pneumatic cylinder (52) to ambient atmosphere. The dispenser of one of claims 1 or 2, wherein said predeterminedly adjustable means (110) comprise a first control rod (112) arranged to be conjointly driven with the pneumatic piston means (70), along an exterior surface of such a cartridge (12) held by the frame (30), without interfering with the last-mentioned cartridge; a second control rod (114) arranged to be selectively linked to or unlinked from the first control rod (112) so as to move conjointly with the first control rod (112), in parallel relation to the first control rod (112), when linked to the first control rod (112), and so as to be independently movable when unlinked from the first control rod (112); means (116) operable manually and selectively by a user to link the second control rod (114) to the first control rod (112), at any position within a range of possible positions along the first control rod (112), or to unlink the second control rod (114) from the first control rod (112); an actuator (118) positionable adjustably along the second control rod (114), at any position within a range of possible positions along the second control rod (114), for conjoint movement with the second control rod (114), the actuator being arranged to actuate the third valve (84) upon conjoint movement of the first control rod (112), the second control rod (114), and the actuator (118) from respective dose-initiating positions relative to the pneumatic cylinder (52), where the piston rod (72) can begin to drive the plunger (20) of such a cartridge (12) held by the frame (30) toward the nozzle (16') of the last-mentioned cartridge (12), to respective dose-concluding positions relative to the pneumatic cylinder (52), where the plunger (20) of the last-mentioned cartridge (12) has been displaced by a distance correlating to a controlled dose of the adhesive from the last-mentioned cartridge (12); whereby the actuator (118) can be adjustably positioned along the second control rod (114) so as to enable the dispenser, when the second rod (114) is linked to the first control rod (112), to inject a controlled dose of an adhesive from such a cartridge (12) held by the frame (30) with the last-mentioned dose being less than full contents of the last-mentioned cartridge. The dispenser of claim 3, wherein the means (116) operable manually and selectively by a user comprise a linking lever (140) attached to one end of the second control rod (114) so as to retain the linking lever (140) on the end of the second control rod (114) but to permit a limited range of pivotal movement of the linking lever (140) on the end of the second control rod (114), the linking lever (140) having an aperture (142), through which the first control rod (112) extends with a loose fit allowing the first control rod (112) to pass freely though the aperture (142) except when pivotal movement of the linking lever (140) causes the linking lever (140) frictionally to engage the first control rod (112), means (130) for basing the second control rod (114) in the reverse direction, and means (150) operable manually by a user to position the linking lever (140) selectively in a pivotal position permitting the first control rod (112) to pass freely through the aperture (142) or in a pivotal position causing the linking lever (140) frictionally to engage the first control rod (112) as mentioned. The dispenser of claim 4, wherein the means (116) operable manually by a user to position the linking lever (140) comprises a cam (150) mounted operatively in fixed relation to the pneumatic cylinder (52) and arranged to be manually adjusted between a condition wherein the cam (150) engages and is interposed between the linking lever (140) and adjacent structure (146) so as to position the linking lever (140) in the pivotal position permitting the first control rod to pass freely through the aperture (142) and a condition wherein the cam (150) permits the means (130) for basing the second control rod (114) in the rearward direction to pivot the linking lever (140), via the second control rod (114), to the pivotal position causing the linking lever (140) frictionally to engage the first control rod (112) as mentioned. The dispenser of claim 4, wherein the means (116) operable manually by a user to position the linking lever comprises a cam (230) mounted operatively to the linking lever (140) and arranged to be manually adjusted between a condition wherein the cam (230) engages and is interposed between the linking lever (140) and adjacent structure (120) so as to position the linking lever (140) in the pivotal position permitting the first control rod (112) to pass freely through the aperture (142) and a condition wherein the cam (230) permits the means (130) for biasing the second control rod (114) in the rearward direction to pivot the linking lever (140), via the second control rod (114), to the pivotal position causing the linking lever (140) frictionally to engage the first control rod (112) as mentioned. The dispenser of one of claims 2 to 6, wherein the pneumatic mechanism (50) comprises a manually actuated fourth valve (86) arranged, when actuated manually with the pneumatic mechanism connected to the source (58) of pressurized air, to divert pressurized air entering the pneumatic mechanism, along with a hose (218) connected to and arranged to receive pressurized air from the fourth valve (56). The dispenser of claim 7, wherein the pneumatic mechanism (50) comprises a nozzle (222) connected to the hose (218). The dispenser of one of claims 1 to 8, arranged for a two-part adhesive, as provided in a cartridge (12) having two chambers (14), each containing one of two parts of the adhesive, wherein said nozzle (16) is a mixing nozzle arranged to mix such parts of the adhesive, a plunger (20) being provided within each chamber, the pneumatic mechanism (50) comprising a pair of piston rods (72) operable in tandem, extended through one end of the pneumatic cylinder (52) and arranged to move conjointly with the pneumatic piston means (70), each piston rod (72) being arranged to drive the plunger (20) of a respective one of the chambers (14) and each piston rod (72) being arranged to withdraw from the last mentioned plunger when the pneumatic piston means (70) is driven in the reverse direction.

Inventors: ERNST RICHARD JOHN, OLMA MARIAN, PAUL SIGISMUND, SEVALD FREDERICK G, ERNST, RICHARD JOHN, OLMA, MARIAN, PAUL, SIGISMUND, SEVALD, FREDERICK G.
Applicants: ILLINOIS TOOL WORKS, ILLINOIS TOOL WORKS INC.
Application year: 1990
Main classification: B05C17
IPC codes: B05C17, B05C5, B05C11, B05D7