US3401847A - Pneumatically powered applicator - Google Patents

Description

p 1968 K. G. DOWNING 3,401,847

PNEUMATI CALLY POWERED APPLI CATOR Filed April 5, 1967 2 Sheets-Sheet 1 a0 a We /4 I111 llllllllllllln o H o o /Ke/7/7e 2% 6. flown/ 9 INVENTOR.

BY Magda & PM!

P 1968 K. G. DOWNING PNEUMATICALLY POWERED APPLICATOR- 2 Sheets-Sheet 2 Filed April 3, 1967 United States Patent O 3,401,847 PNEUMATICALLY POWERED APPLICATOR Kenneth G. Downing, Houston, Tex., assignor to Thermon Manufacturing Company, a corporation of Texas Filed Apr. 3, 1967, Ser. No. 628,079 6 Claims. (Cl. 222-327) ABSTRACT OF THE DISCLOSURE A pneumatically powered applicator having a manually activated valve to utilize compressed air to successfully move an applicator plunger or piston to extrude the contents of the cylinder through an output nozzle.

BACKGROUND OF THE INVENTION (1) Field of the inventin.The invention pertains in general to the controlled application of a composition to a given environment and in particular to the application, in discrete amounts, of a heat transfer material to a steam tracer line or other heating element generally used in maintaining a material transfer conduit at a given temperature. As is well known, such heat transfer material is used in certain industries where materials are conveyed from one processing point to another through pipelines or the like. The pneumatic applicator of the present invention is particularly suitable for applying heat conductive material. As will be appreciated from the following description, the applicator of the present invention is also suitable for use in the controlled application of calking compositions, lubricants, or any other semifluid substance.

(2) Description of the prior art.Heretofore, mechanically actuated calking guns have been used for applying heat transfer material and the like. Although hand powered mechanical guns are satisfactory for use for short periods of time, they are too tiring for continuous use over prolonged periods of time.

SUMMARY OF THE INVENTION The construction of the present applicator utilizes operator control but with a minimum of manual effort so that it may be used without causing the operator to become excessively fatigued. Further, it is economical in that it is fabricated using many of the structural components of a standard, manually operated calking gun. The working components of the applicator of the present invention are commercially accessible and may be repaired or replaced with relative ease. In contrast to many prior art devices, the entire applicator unit is self-contained and portable, requiring only a source of compressed air for power.

The pneumatic power supplied to the applicator is converted into a reciprocating mechanical movement by introducing the compressed air into a cylindrical chamber which drives a spring-loaded power piston. A rod attached to the power piston drives a double pawl and ratchet mechanism which in turn drives a second piston or plunger through the applicator cylinder containing heat transfer material or other semifluid composition for extruding the composition from a nozzle at the end of the applicator cylinder.

It is thus an object of the present invention to provide BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation of a first form of the pneumatic applicator of the present invention;

3,401,847 Patented Sept. 17, 1968 FIG. 2 is a partial vertical section illustrating several operating details of the applicator of FIG. 1;

FIG. 3 is a vertical section illustrating several additional operating details of a slightly modified embodiment of the pneumatic applicator of the present invention; and

FIG. 4 is a horizontal section taken along the line 44 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The applicator of this invention includes a loading or applicator cylinder 10 connected to a handle 11. A power cylinder 12 is mounted above the loading cylinder 10. The handle 11 carries an air valve 13 which may be opened or closed by actuation of a valve trigger 13a. One side of the valve 13 is connected by an air line 14 to the power cylinder 12. The other side of the valve 13 is connected to a supply line 15 which in turn is connected to a source (not illustrated) of compressed air.

As best illustrated in FIGS. 2 and 3 of the drawingss, the compressed air from the supply line 15 enters the air line 14 through the air valve 13 where it is then introduced into a chamber 12a in the power cylinder 12. The pressure of the air in the chamber 12a displaces a power piston 16 aganst the force of a spring 17, When the chamber 12a is depressurized, the spring 17 restores the piston 16 to its rest position (to the right in FIG. 3). An opening 12b is provided in a removable cap at the end of the power cylinder 12 to vent the air contained within the cylinder 12 between the piston 16 and the cap 12a. A piston rod 16a transmits the movement of the piston 16 to a drive arm 18 through a pin 18a. In the preferred embodiment, the power cylinder 12 is adapted to pivot slightly about a pivot pin 24 to accommodate the arcuate movement of the pin 18a relative to the drive arm 18. The drive arm 18 is pivotally secured at its lower end to the handle 11 by a pivot pin 18b.

As illustrated in FIGS. 3 and 4, a spring loaded pawl 19 is pivoted about a pivot pin 19a secured to the drive arm 18. A spring 19b is mounted on the outer ends of the pivot pin 19a (FIGS. 3 and 4) and is confined under compression between the lower surface of the pawl 19 and the forward surface of the arm 18 so as to exert a constant resilient force tending to pivot the pawl 19 clockwise (FIG. 3) to hold it in contact with the ratchet teeth 20b while allowing the pawl 19 to pivot counterclockwise enough for the pawl 19 to move rearwardly (to the right in FIG. 3) relative to the teeth 20b when the arm 18 is retracted to the right (FIG. 2). A second spring-loaded backup pawl 21 is pivoted about a pin 21a and also engages the teeth 20b. The pawl 21 is urged resiliently into constant contact with the rachet teeth 20b by a compressed spring 21b which has its intermediate portion coiled about the ends of the pivot pin 21a and has its ends in engagement with the lower surface of the pawl 21 and a stop 21c secured to the handle 11. Thus, the pawl 21 is urged in a clockwise direction about its pivot pin 21a, but it may pivot slightly in a counterclockwise direction (FIG. 3) to allow the teeth 20b to move forwardly or to the left relative to the pawl 21. The rod 20a is removably secured at one end to a plunger 20 carried within the applicator cylinder 10. The other end of the rod 20a has a handle 21c so as to facilitate retraction of the plunger 20 (to the right in FIG. 3) after the rod 20a has been partially rotated to disengage the ratchet teeth 2012 from the pawls 19 and 21, as will be more fully explained.

As viewed in FIG. 3 of the drawings, movement of the drive arm 18 to the left is transmitted to the rod 20a through the pawl 19. When the rod 20a moves to the left, the backup pawl 21 merely slips over the ratchet teeth 20b. Movement of the arm 18 to the right draws the pawl 19 to the right in a slipping movement over the teeth 20]). The rod 20a is prevented from moving to the right as the pawl 19 moves to the right because the engagement of the backup pawl 21 in a notch of the teeth 20]) locks the rod 20a against such movement.

The pawls 19 and 21 may be disengaged from the teeth 20b by partially rotating the rod 20, generally about 90 from the engaged position illustrated in FIG. 3 of the drawings to the released position illustrated in FIG. 1. When the teeth 20b have been thus disengaged, the rod 20 may be moved by hand in either direction in the cylinder 10.

The form of the applicator illustrated in FIG. 3 of the drawings is adapted to be employed with a disposable cylindrical cartridge 22 which is prefilled with a heat transfer cement or other material 23. Preferably, the cylinder has a forward removable cap 30 which is threaded at 30a to the cylinder 10 or is otherwise remo-vably secured thereto. The cap 30 has an aperture 30b therethrough. At the other end of the cylinder 10, a removable cap 31 is preferably threaded thereto at 31a, and it has an opening 31b through which the rod a extends.

The cartridge 22 is of conventional construction and is usually provided at one end with a nozzle 22a and at its other end with a movable disk 22b or similar element. As the plunger 20 advances to the left in FIG. 3, the element 22b is forced along the inside of the cartridge 22 by the plunger 20, causing the material 23 to be extruded through the nozzle 22a which projects outwardly through the opening b. The cap 30 may be disengaged from the applicator cylinder 10 and the cartridge 22 may be replaced after the contents 23 have been dispensed therefrom. When a new cartridge 22 is being inserted into the loading cylinder 10, the piston 20 is restored to its starting position by turning the handle 200 to disengage the teeth 20b from the pawls 21 and 19 so that a smooth portion of the rod 20a may slide over the pawls 19 and 21.

The embodiment illustrated in FIG. 2 of the drawings is the same as that of FIG. 3 except that the material 23 is placed directly in the bore of the cylinder 10 rather than in the separate cartridge 22. In the modification of FIG. 2, the piston 120 has an outside diameter corresponding to the inside diameter of the cylinder 10. The cylinder cap 130 has an attached or integrally formed nozzle 13%. Thus, the applicator of this invention may be readily adapted for either cartridge type loading or cylinder loading of the material to be dispensed.

FIG. 2 includes a schematic illustration of the air valve 13 which is secured to the handle 11 by bolt or rivet 13 It should be understood that the illustrated form of the valve 13 is exemplary and any valve capable of providing the desired function may be employed. The valve 13 is spring loaded so that is closed in its off or rest position (FIG. 2 and dotted line position of FIG. 3). When a trigger 13a is squeezed or actuated to its on position (solid line position of FIG. 3), it rotates a cylindrical valve gate 13b to cause a central passage 130 to register with the opening 15a in the supply line 15 and an opening 14a in the air line 14. With the form of the valve 13 illustrated in FIG. 2 of the drawings, the chamber 12a in the power cylinder 12 remains pressurized until the trigger 13a is released. The release of the trigger 13a allows a spring 13d to restore the valve gate 13b to the off or rest position where the chamber 12a may be vented through a channel 13a in the valve gate 13b. Each opening and closing of the valve 13 produces only one cycle or stroke of movement of the piston 16. If desired, the valve 13 may be replaced by a valve mechanism which will continuously open and close to produce repetitive strokes of the piston 16 automatically so long as the trigger 13a remains depressed. In such a modification, the piston 20 would continue to advance through the applicator cylinder 10 until the valve trigger 13a is released.

In operating the embodiment illustrated in FIGS. 1 and 2 of the drawings, the handle 200 is first rotated to disengage the pawls 19 and 21 from the teeth 20b. The handle 200 is drawn to the right to position the piston at the extreme right-hand end of the cylinder 10. The end cap is then removed and the cylinder 10 is filled with material 23. The end cap 130 is replaced and the handle 20c is rotated to re-engage the pawls 19 and 21 with the teeth 2%. The nozzle 13% is then positioned in the desired area and the trigger 13a is pulled into the handle 11. The plunger 120 advances a distance determined by the stroke of the piston 16 and thus for each stroke of the piston 16, a quantity of the material 23 is extruded through the nozzle 13Gb.

In the embodiment illustrated in FIG. 3 of the drawings, the smaller piston 20 is positioned at the extreme right of the cylinder 10 by disengaging the teeth 20.: and the pawls 19 and 21 and pulling the rod 20a to the right. The end cap 30 is removed, a full cartridge 22 is positioned in the cylinder 10, and the cap 30 is replaced. The operator places the nozzle 22a in the desired position and squeezes the trigger 13a. Such squeezing takes only a minimum of effort and may be accomplished with one finger if desired. The piston 20 moves a predetermined amount to advance the movable disk 22b through cartridge 22, causing a quantity of the material 23 to extrude through the nozzle 22a for each stroke of the piston 16.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape, and materials as well as in the details of the illustrated construction may be made within the scope of the appended claims without departing from the spirit of the invention.

I claim:

1. An applicator for applying putty-like material to a desired work area comprising:

(a) an applicator cylinder for containing a putty-like material;

(b) a plunger disposed in said applicator cylinder for longitudinal movement relative thereto for dispensing the semifiuid material from the cylinder;

(c) pneumatic power means for longitudinally moving said plunger within said applicator cylinder;

((1) movement transmission means operably connecting said pneumatic power means to said plunger for imparting only forward movements to the plunger from the pneumatic power means for effecting the dispensing of the material in said applicator cylinder; and

(c) said pneumatic power means including:

(1) a piston movable for a forward stroke by fluid pressure supplied thereto;

(2) resilient means to return said piston after its forward stroke;

(3) a drive arm pivotally connected to said piston; and

(4) a power pawl mounted on said drive arm for movement with said drive arm.

2. The applicator of claim 1 including:

(a) a handle on said applicator cylinder so that the entire applicator may be manually held by a user;

(b) valve means for said pneumatic power means including trigger means for opening and closing said valve means; and

(0) means mounting said valve means with said handle.

3. The applicator of claim 1 wherein:

(a) said applicator cylinder is adapted to receive a cartridge containing said putty-like material and having a nozzle therewith;

(b) said plunger being slidably received in the rearward end of said cartridge for forcing the material therein from the nozzle as said plunger moves longitudinally relative to said cylinder; and

(c) said cylinder having a centrally apertured removable end cap through which said cartridge nozzle extends.

4. The applicator of claim 1 including:

(a) an end cap removably disposed at the forward end of said applicator cylinder; and

(b) an integrally formed nozzle with said end cap through which said material in said cylinder is dispensed.

5. The structure set forth in claim 1 wherein said movement transmission means includes:

(a) ratchet teeth on said rod engageable by said power pawl for moving said rod forwardly while slipping relative thereto as said power pawl is moved rearwardly upon the return of said piston by said resilient means; and

(b) a backup pawl also engageable with said ratchet teeth for preventing said rod from being moved rearwardly as said power pawl moves rearwardly.

' 6 6. The structure set forth in claim 1, including: (a) a power cylinder for said piston mounted with said applicator cylinder; and (b) means pivotally mounting said power cylinder on said applicator cylinder for relative pivotal movement thereof as said drive arm reciprocates.

References Cited UNITED STATES PATENTS 2,815,151 12/1957 Collins 222-327 2,923,442 2/ 1960 Maras 222-391 X 2,995,159 8/1961 Berggren 222-334 X 2,998,289 8/ 1961 Runciman 222-39l X SAMUEL F. COLEMAN, Primary Examiner.

Images