The invention described below relates to hand tools and, more particularly, to manually actuated caulking guns.
Caulking guns have been developed to provide a convenient way to dispense caulking or silicone compounds from cartridges. The cartridges themselves are generally made with a built-in plastic nozzle and provide a sliding plug on the opposite end of the nozzle. Caulking guns generally include a cartridge holder, a plunger with a shaft for pushing the compound in the cartridge, a handle and a trigger mechanism for advancing the plunger. Once the tip of a nozzle is cut, the seal of a cartridge broken using a poker and the cartridge has been placed in the gun, a user squeezes the trigger, advancing the plunger. The plunger in turn pushes the plug and the cartridge extrudes compound. The previous art generally includes a handle and a plunger advancing mechanism towards the back end of the gun. These guns commonly use two coil springs to achieve the tensions necessary on the plunger's parts. Some more sophisticated guns have “no drip” features that release the pressure on the plungers so that compound does not leak from the nozzles when not in use. Current automatic pressure release mechanisms use additional springs and parts to relieve pressure on the cartridge. These mechanisms relieve a plunger's pressure each time a trigger is released. Other guns require a user to depress a tab to release pressure on the cartridges. Some caulking guns include built-in nozzle (snout) cutters. U.S. Pat. No. 6,045,005 describes a circular opening in the side of a handle with a blade on a trigger for cutting the tip of a nozzle. Although a need for simple construction has been noted in the prior art, multiple coil springs have remained common to most caulking guns, some using as many as three springs, cables, ratchets and tabs which a user must activate to operate.
The construction and operation of common caulking guns necessitate a user to hold the gun with both hands for accurate delivery of compound. Usually one hand cradles a cartridge holder and cartridge; the hand's position supports the majority of the gun's weight. The other hand grips a handle and squeezes a trigger. Although this method of operation is adequate for many uses, some applications do not readily allow a user to hold a gun with both hands. In such cases, a user must support the weight of the entire gun with one hand putting added stress on the user's wrist and making precise delivery of compound more difficult. Some situations call for a user to use one hand for bracing his/her own body and only use a gun with the other hand, for example while standing on a ladder. Other situations call for a user to hold an object with one hand and apply compound with a gun in the other hand. In these cases, the user must draw back the hand holding the gun to align a nozzle's tip with the object being held. Operating a common caulking gun in a drawn back position is awkward, potentially imprecise and may quickly fatigue a user's wrist.
Although the usual design of caulking guns includes a handle and trigger at the rear, two patents show variations to this arrangement. U.S. Pat. No. 6,640,998 describes a device wherein a cartridge holder slides back against a non-moving plunger. Although this action claims to improve the balance of their invention during use, the entire weight of a full cartridge still hangs in front of a user's hand when a new cartridge is placed in the device. Furthermore, this design has the drawback that as a trigger is squeezed, a nozzle's tip pulls away from the point of contact. This motion requires that a user constantly adjust the gun forward during use. U.S. Pat. No. 4,957,223 describes a handle that is placed towards the front of a caulking gun and uses a complex combination of springs and cables to cause it to function. This design may allow for a better balance at the beginning of use if only one hand holds such a gun, but the device does not allow for the option to operate it by the method of cradling the gun with one hand and gripping the handle with the other hand.
It is, accordingly, the object of the present invention to provide a caulking gun whose balance point is adjustable.
Another object of the present invention is to provide the ability to adjust the balance point even while a cartridge remains in a cartridge holder.
Another object of the present invention is to be usable and balanced with either a two-handed grip or single-handed grip.
Another object of the present invention is to provide a sliding handle for adjusting and setting the balance point of a gun.
Another object of the present invention is to provide a simple mechanism for the disengagement and reengagement of a handle from an upper body of the gun using a trigger.
Still another object of the present invention is to reduce the number of springs in an advancing mechanism by eliminating the need for multiple springs, and instead use one spring.
Another object of the present invention is to provide a simple automatic means to relieve pressure on a cartridge to prevent oozing after a trigger is squeezed and released without the need for additional springs.
Yet another object of the present invention is to move the location of a nozzle cutter away from the inside of a handle where plastic nozzle tips and caulking compound may lodge; and to move it to the front of a gun where it is more visible, in alignment with a handle and where cut nozzle tips will not be trapped.
Another object of the present invention is to provide an arm support clip that may be employed or left in a retracted position.
Still another object of the present invention is to provide a design that is easy to manufacture and assemble.
The design of this invention has a cartridge holder portion which includes a disk with an opening for a cartridge nozzle, two parallel cartridge rails that extend rearward, a hollow stock portion connected to said rails wherein is found an actuator spring, actuating plates—one plunger advancing plate and one plunger restraining plate—and through which a plunger shaft passes.
A handle and trigger are positioned below a cartridge holder and stock, and can slide along a lower cartridge rail. A means must connect a trigger and a plunger advancing plate such that it causes said plate to move forward when said trigger is squeezed, yet allows adjustment of the handle's position should a user prefer a different balance point for the gun.
Two separate functions are required to allow a handle to slide: First, a handle repositioning means must be able to disengage a handle from a gun's lower cartridge rail, allow said handle to move to a new position, and then reengage said handle. Second, a plunger advancing means must be able to disengage a trigger from a plunger advancing plate, allow a handle to be moved to a new position, and then reengage said trigger to said plate.
Here described are four embodiments of mechanisms that connect a handle to the rest of a gun and a trigger to a plunger advancing plate.
In a first embodiment, these two actions must be performed separately; each action designed to operate independently using fasteners that engage a handle into indentations in a lower cartridge rail and fasteners that engage a trigger into indentations in a connecting bar (otherwise referred to as a trigger bar) that extends back to a plunger advancing plate. Two examples of fastener types include locking tabs that slide up or down, or thread screws. A user is required to release a fastener that locks a handle to a gun, release a fastener that connects a trigger to a trigger bar, move the handle's position, then re-lock each fastener.
In a second embodiment, two separate sprung tabs engage a handle to indentations in a lower rail and a trigger to indentations in a trigger bar. These tabs are placed in alignment such that as a user pushes a button at the rear of said handle, a shaft, connected to said button and positioned inside said handle, engages said tabs. Said shaft moves forward, collapses said tabs simultaneously, permitting said handle to be positioned at a different point along the gun; releasing said button resets said tabs against said indentations. This arrangement requires that both tabs align with their respective indentations simultaneously for a handle and trigger to be reengaged for use.
With a third embodiment, a spool, positioned transversely to a handle, is connected to a trigger. A thin cable wraps around said spool, extends back, and is connected to a tab in a plunger advancing plate. When said trigger is squeezed, rather than spin, said spool locks and is pushed forward. To release said handle for repositioning along the gun, a forked tab attached to said handle slides up and down, releasing said handle from a lower cartridge rail. As said handle slides, said spool automatically picks up or releases slack on said cable as needed.
A fourth and preferred embodiment provides a sliding vertical forked tab at the rear of a handle, said tab engaging indentations in a lower cartridge rail; and a trigger including a toothed extension, a trigger bar having indentations, said extension and trigger bar indentations engaging only when said trigger is squeezed. A spring is positioned inside the trigger: one end of said spring biases said trigger away from a handle, the other end of said spring is attached to said tab. With this arrangement, a handle can be released, moved and then relocked in one easy maneuver using only a trigger.
Attached to the lower forward portion of a lower cartridge rail, a brace includes an opening to receive and support the front edge of a trigger bar—the front edge of said bar being sharpened or including a small blade. Another opening in said brace allows nozzles of common cartridges to be inserted therein. Said sharpened edge and brace thus form a guillotine type nozzle cutter.
A plunger restraining plate is bent backwards and straddles the upwardly sloping rear portion of a trigger bar. As said bar begins moving forward when a trigger is squeezed, it engages said plate, lifting it slightly releasing a plunger shaft. As said trigger is released, said plate is delayed in restraining said shaft, thus permitting said shaft to slide rearwards slightly, relieving pressure on a cartridge. This action occurs automatically each time a trigger is released after being squeezed.
An arm clip, pivotally attached to a stock, may be used to give a second point of contact with a user's arm for greater support, accuracy and endurance.
Although multiple springs may be used to produce the actions necessary for the actuator plates to function, a single actuator spring design simplifies the construction of the gun. A single spring design may be used with a gun that does not have a sliding handle. In the preferred embodiment, a caulking gun includes a sliding handle, is manufactured as simply as possible and allows for both a handle and trigger to release for adjustment with one simple maneuver.
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A sliding handle (15) with trigger (16) is channeled (15a), permitting lower cartridge rail (12) to pass there through. Lower cartridge rail (12) includes indentations (12a) along its long axis. Handle (15) may be set anywhere along lower cartridge rail (12) at any given indentation (12a). Handle (15) also shown shadowed in the rearward position as handle (15-I). Nozzle cutter (17), attached to rail (12), supports the front edge of trigger bar (32).
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Number | Date | Country | |
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60763469 | Jan 2006 | US |