Caulking Gun Load Sensitive Variable Ratio Drive Device

Abstract

Disclosed systems provide cost effective dispensers of construction sealant, sausage tubes and other products having varied and even unknown levels of viscosity. A variable ratio drive cam pivots in response to the trigger tension caused by the viscosity of the material to be dispensed. In a relative high force mode, encountered with high viscosity payloads, the drive cam slightly pivots, keeping the distance traveled by the drive rod relatively small in response to a pull of the trigger. This results in a relatively high thrust ratio. Conversely, in dispensing a product with a relatively low viscosity, the drive cam pivots by a greater degree, causing a longer movement of the drive rod in response to the distance traveled by the trigger resulting in a lower thrust ratio. The system works well in caulking guns, bulk loading tools and multi tube tools, such that multiple tools are not required.

Claims

1. A variable thrust ratio tool for pushing a substance and adapting the thrust ratio in response to the viscosity of the substance, the tool comprising: a) a drive rod slidably attached to a drive dog; b) a variable ratio drive cam pivotally attached to a drive cam pivot axle, the drive cam pivot axle disposed below the drive rod and to the rear side of the drive dog; c) an elastic member having a first end attached to the variable ratio drive cam and the elastic member having a second end attached to a trigger, the trigger pivotally attached to a handle.

2. The tool of claim 1 wherein the trigger is pivotally attached to a tool piece frame.

3. The tool of claim 1 wherein a trigger axle pivotally attaches the trigger to the handle.

4. The tool of claim 1 further including a drive dog release stop disposed to the rear of the drive dog.

5. The tool of claim 1 wherein the variable ratio drive cam comprises a relatively flat section sometimes used to apply force to the drive dog.

6. The tool of claim 5 wherein the variable ratio drive cam further comprises a radius section disposed above the flat section.

7. The tool of claim 6 wherein the radius section of the variable ratio drive sometimes urges the drive dog forward in order to increase the distance traveled by the drive rod in response to a pull of the trigger.

8. The tool of claim 1 further including a trigger return spring having a first end attached to the trigger and the trigger return spring having a second end attached to the handle.

9. The tool of claim 8 wherein the second end of the elastic member is attached to a drive cam spring lower mount rivet and the drive cam spring lower mount rivet is attached to the trigger.

10. The tool of claim 9 wherein the first end of the trigger return spring is attached to the drive cam spring lower mount rivet.

11. The tool of claim 1 wherein the variable ratio drive cam generally takes the form of a U.

12. The tool of claim 11 wherein the first end of the elastic member attaches to a distal end of the variable ratio drive cam.

13. The tool of claim 12 wherein the drive cam pivot axle is pivotally attached through a proximal side of the variable ratio drive cam.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is a side sectional view of a disclosed embodiment in neutral mode

[0022] FIG. 2 is a front sectional view of a disclosed embodiment

[0023] FIG. 3 is a side sectional view of a disclosed embodiment in a low force mode which contemplates the use of sealant with a relatively low viscosity

[0024] FIG. 4 is a side sectional view of a disclosed embodiment in a high force mode which contemplates the use of sealant with a relatively low viscosity

[0025] FIG. 5 is a perspective view of a disclosed embodiment

[0026] FIG. 6 is a side view of a disclosed embodiment

REFERENCE NUMERALS IN THE DRAWINGS

[0027] 1 drive dog [0028] 2 variable ratio drive cam or drive cam [0029] 3 trigger axle [0030] 4 handle [0031] 5 drive cam load spring [0032] 6 drive cam pivot axle [0033] 7 drive dog release stop [0034] 8 contact point of drive cam to drive dog in a neutral or high force state [0035] 9 trigger return spring [0036] 10 trigger [0037] 11 drive cam spring lower mounting rivet [0038] 12 drive rod [0039] 13 upper radius portion of the variable ration drive cam shown in contact with the drive dog in FIG. 3, the upper radius also located above the drive cam pivot cam 8 [0040] 14 drive cam shown following the trigger with cam load spring not being extended due to the low force on the drive rod 12 [0041] 15 load spring shown in the low force mode [0042] 16 distance the drive dog 1 moves with one trigger actuation in Low Force mode [0043] 19 trigger in an actuated position [0044] 21 distance drive dog 1 moves with one trigger actuation in High Force mode [0045] 23 contact point between drive cam and drive dog in High Force mode [0046] 24 load spring fully extended in the High Force mode [0047] 25 trigger in an actuated position [0048] 29 drive dog/drive rod spring [0049] 30 distal end of variable ratio drive cam connected to drive cam load spring 5 [0050] 31 component configuration wherein the contact point between a variable ratio drive cam 2 and drive dog 1 in the Low Force mode [0051] 35 end piece, plunger or pressure plate [0052] 40 optional frame to retain a caulking cartridge

[0053] These and other aspects of the present invention will become apparent upon reading the following detailed description in conjunction with the associated drawings.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0054] The following detailed description is directed to certain specific embodiments of the invention. However, the invention can be embodied in a multitude of different ways as defined and covered by the claims and their equivalents. In this description, reference is made to the drawings wherein like parts are designated with like numerals throughout.

[0055] Unless otherwise noted in this specification or in the claims, all of the terms used in the specification and the claims will have the meanings normally ascribed to these terms by workers in the art.

[0056] Unless the context clearly requires otherwise, throughout the description and the claims, the words comprise, comprising and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in a sense of including, but not limited to. Words using the singular or plural number also include the plural or singular number, respectively. Additionally, the words herein, above, below, and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application.

[0057] Referring to FIG. 1, a disclosed embodiment is shown in neutral mode wherein no pressure in being applied to a tube or other workpiece. A drive dog 1 is shown in relatively close proximity or resting upon a drive dog release stop 7.

[0058] A mid, medial section or flat section of a variable ration drive cam 2 is shown in contact with the proximal side of the drive dog 1.

[0059] The trigger return spring 9 may have a first end attached to the trigger with an opposite end and a second end attached to the handle or frame of the gun. The first end of the trigger return spring may intersect, be attached to or travel through the drive cam spring lower mounting rivet to gain a mechanical advantage of being directly connected to the second end or lower end of the drive cam load spring 5. The direct connection increases the return force of the trigger return spring and also more securely attaches the lower end of the drive cam load spring to more efficiently rotate the variable ratio drive cam.

[0060] Referring to FIG. 3, a disclosed embodiment is shown in a relative low force state wherein a tube of sealant or other product has a relatively low viscosity and thus requires relatively less force to apply. The trigger is in an actuated position with a low force being applied. The force is too low to extend the load spring so the drive cam stays in the low force position and the load spring is shown in a contracted state 15. The upper radius 13 or upper portion of the drive cam is shown in contact with the drive dog 1 which results in a relatively longer movement of the drive rod. The resulting distance is shown as the distance 16 between the drive dog 1 and drive dog release stop 7. This relatively greater distance results in a relatively lower thrust ratio that may be in the relatively lower range of 3:1 to 16:1.

[0061] The drive cam 2 or may comprise a proximal end or end near a user with the proximal end comprising an oblong portion such as the relatively flat portion shown in contact with the drive dog in FIG. 1 and FIG. 4, the flat portion may transition upwardly into a radius or rounded portion such as the portion shown in contact with the drive dog in FIG. 3. The proximal portion of the drive cam may be pivotally connected to the handle assembly by use of a drive cam pivot axel 6.

[0062] The drive cam 2 may further comprise a middle section taking the form of a U shape so as to be positioned below the drive dog but yet allow the drive dog to by near or touching the radius for an efficiency of movement and conservation of space within the frame of the disclosed embodiment. A distal or far section of the drive cam may take an upward angle so as to be generally in the same plane as the drive cam pivot axel and may define a void to accept the superior end of the drive cam loading spring.

[0063] The U shape of the drive cam overcomes shortfalls in the related art and/or provides a unique mechanical advantage by allowing the drive rod to move at a greater distance by getting out the way of the drive dog in a low force mode FIG. 3 and by having an initial starting point for the upper end of the drive cam loading spring to be near the same plane as the drive cam pivot axel.

[0064] The U shape of the drive cam further overcomes shortfalls in the related art and/or provides a unique mechanical advantage in that the relative level of the upper end of the drive cam loading spring remains relatively near the same plane as the drive cam pivot axel so as to move the drive rod a relatively shorter distance in a high force mode as shown in FIG. 4.

[0065] The use of a drive dog in contact or in constant contact with some portion of the oblong portion or upper radius portion of the drive cam in either a low force or high force mode, overcomes shortfalls in the related art and/or provides a unique mechanical advantage in that resistance encountered by the drive rod, as a result of sealant viscosity, is transmitted to the drive cam load spring which in turn is transmitted to the drive cam spring lower mounting rivet 11 with the lower mounting rivet attached the trigger such that the user's effort in using the trigger during use is efficiently used to adjust the distance of drive rod movement by the resulting pivotal movement of the drive cam.

[0066] However, the thrust ratio range is variable and is adjusted by the length/tension of the drive cam load spring as such length/tension increase in proportion to the resistance the drive rod and drive dog experience as a result of the end piece or plunger 35 (see FIG. 5) pushing upon the sealant.

[0067] FIG. 4 shows a disclosed embodiment in a state of high force as a result of the end piece or plunger pushing against a sealant of relatively high resistance or high viscosity. As a result, the load spring is shown in a state of expansion 24 as the trigger pull expands the load spring as the load cam fails to easily move the drive dog. Thus, the point of contact 23 between the drive dog and drive cam is in the middle or medial portion lower radius of the drive cam, resulting in a relatively shorter movement of the drive rod. This relatively shorter movement increases the relative thrust ratio. The shorter movement or shorter distance can be seen in distance 21 between the drive dog and drive dog release stop. This relatively shorter drive rod distance increases the thrust ratio to the approximate range of 17:1 to 32:1.

[0068] FIG. 5 shows a disclosed embodiment attached to a tube holder frame and other components to create a caulking gun. Other configurations are contemplated

[0069] The terms spring, elastic member and resilient member refer to any component capable of expansion and having a bias to return their original condition.

[0070] The term payload refers to any substance used by a disclosed embodiment which may include caulk, construction materials, food stuffs and any material that may be dispensed by force.

[0071] The term tool piece frame refers to a frame supporting or attached to any of the components of a disclosed embodiment.

[0072] The above detailed description of embodiments of the invention is not intended to be exhaustive or to limit the invention to the precise form disclosed above. While specific embodiments of, and examples for, the invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. For example, while steps are presented in a given order, alternative embodiments may perform routines having steps in a different order. The teachings of the invention provided herein can be applied to other systems, not only the systems described herein. The various embodiments described herein can be combined to provide further embodiments. These and other changes can be made to the invention in light of the detailed description.

[0073] All the above references and U.S. patents and applications are incorporated herein by reference. Aspects of the invention can be modified, if necessary, to employ the systems, functions and concepts of the various patents and applications described above to provide yet further embodiments of the invention.

[0074] These and other changes can be made to the invention in light of the above detailed description. In general, the terms used in the following claims, should not be construed to limit the invention to the specific embodiments disclosed in the specification, unless the above detailed description explicitly defines such terms. Accordingly, the actual scope of the invention encompasses the disclosed embodiments and all equivalent ways of practicing or implementing the invention under the claims.

[0075] While certain aspects of the invention are presented below in certain claim forms, the inventors contemplate the various aspects of the invention in any number of claim forms.