CA1049464A

CA1049464A - Caulking gun

Info

Publication number: CA1049464A
Application number: CA287,925A
Authority: CA
Inventors: Peter J. Y. Chang
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-09-29
Filing date: 1977-09-29
Publication date: 1979-02-27

Abstract

ABSTRACT OF THE DISCLOSURE; An improved caulking gun providing greater trigger-leverage and more nearly parallel trig-ger swing through location of the trigger pivot above the plunger shaft, a provision also providing maximum wear-point-access and oiling reminder, and simplifying fabrication and assembly toget-her with a free-insert drive-grip spring, a self-pivoting release grip retained together with the counter-spring on the plunger shaft:; subassembly requires only three welds for part securance and final assembly securance requires only one rivet and one up-set-attachment.

Description

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This invention relates generally to tools and specifi-cally to manually powered caulking guns.
Principal objects of the invention are to provide an improved caulking gun which is at the same time more e:Efective in use, more durable and conducive to good maintenance, and more economical to fabricate and assemble than previous articles of the kind.
In the prior art various caulking guns have been des-cribed, as for example in the following U. S. patents:
1,986,166 to F. K. Schneider, January 1, 1935

2,530,359 to W. P. Peterson, November 14, 1950 2,561,825 to W. A. Sherbondy, July 24, 1951 Schneider discloses a caulking gun with outboard rear-wardly mounted plunger release and forward trigger pivoted 'oelow the plunger shaft drive grip.
Peterson discloses a caulking gun with forward trigger pi~oted below the plunger shaft drive grip and forward release.
Sherbondy discloses a caulking gun with forward trigger pivoted below the plunger shaft drive grip and plunger shaft re-lease having a substantially horizontal control lever above the plunger shaft.
However neither these nor any other caulking guns are believed to provide the advantages of the present invention ac-cording to the above objects.
In brief summary o~ the invention given for cursive description only and not as limitation, the invention includes in a caulking gun the features o-f trigger pivot and trigger-to-drive grip engagement above a plunger shaft, and a minimum of parts and fabrication including final assembly securance involving only one rivet and one upset-attachment.
The above and other objects and advantages will become more readily apparent on examination of the following clescription ., ...... . .. . ... . .

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including the drawings, in which like reference numerals re-fer to like parts:
Fig. 1 is an isometric view, and Figs. 2 and 3 are side elevational views in section, showing successive operating positions.
Fig. 1 shows external features of the invention 10, which include a pistol-type handle 16 having a generally rectan-gular cross-section open at the top and bottom, with connection at the forward end to conventional structure including a butt cup 18 having a forwardly extending hemi-cylinder 20 terminating in a yoke 22. A plunger shank or plunger shaft 24 of circular cross-section passes horizontally through the upper portion of the handle and has at the rear end a substantially right-angle bend 26 and at the forward end a thrust disk 28 for urging caulking compound from a conventional cylindrical container (not shown) held between the butt cup and the yoke.
; A trigger 30 forward of the handle has pivotal connection inside the handle above the plunger shank at a rivet 32 passing transversely through the handle. Clearly visible inside the han-dle at the top opening is the upper end of the trigger above the pivot, a first grip or plunger drive grip 34 in operational con-tact with the trigger at the rear and with a first spring 36, which is a compression spring resiliently wedged between the for-ward wall of the housing and the plunger drive-grip, the free length of the spring being greater than the spacing between these generally parallel elements.
~ n aperture 38 in the rear wall of the handle below the plunger shank loosely passes a manual-operation release 40 portion - ~ .
of a plunger pressure retainer grip located inside the handle with all other mechanism except the protruding ends of the trigger, release portion and plungerO
Fig. 2 shows the relation of the interior parts of the ., .
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mechanism before the trigger is depressed in a feeding cycle to expel caulklng compound from a typical caulking container C (phan-tom lines).
A second compression spring 42 coaxially on the plunger shaft urges the rearwardly concave second grip 4~ which surrounds the plunger shaft into contact with the rear wall of the handle and urges the trigger 30 forward to rest against the ~utt cup.
The trigger has an aperture 46 passing the plunger shaft through it. ,~
The first grip 34 surrounds the plunger shaft and has an upwardly extending portion whichis the portion actuated at the ~' top of the handle by the trigger. The grips cramp the plunger shaft in conventional manner, but oppositely, when canted rela-tive to it, and respectiveiy release it when perpendicular to it, the first under urging of the first spring and the second when manually actuated by the~elease portion.
Fig. 3 shows the first grip cramped on and advancing the plunger shaft under thrust of the trigger against the arm provided by the upward extension of the grip, compressing first spring 36 which has a compressed length proportioned to stop the , stroke when fully compressed and which extends to release the cramping and return the grip and trigger to the position of the , previous Figure. It will be appreciated that the second spring 42 also urges the trigger to the initial stroke position.
Several advantageous features will be apparent. There are only six moving parts, two identical springs, two grips made ~, from perorate, 1at plate, a trigger and a plungerO The great efective length o~ the trigger achieved by perforating it to pass the plunger and pivoting it high in the handle gives great mechani-' 30 cal advantage and a longer-radius, making the squeezing action required to advance the plunger more nearly parallel action. The high-load portion of the mechanism which should be kept lubricated for easy operation and longest wear is at the operative contact of .' - ' .
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~ (~49464 the trigger with the first grip, and this is highly visible and readily accessible for inspection and oiling.
The plunger pressure release mechanism is freely pi-voted about the plunger shaft and requires no adjustment or other attachment, being retained laterally between the side walls and bearing on the rear wall of the housing. The springs prevent the mechanism from rattling and the handle guards it from damage.
It is evident also that sub-assembly requires only three welds: yoke and butt cap to hemi-cylinder, and handle ~o butt cup, and one bend in the plunger shank.
Pinal assembly is also impressively simple, requiring only inserting the plunger shank through the hole in the handle, the second grip, the second spring, the trigger, the first grip, the butt cup and the thrust disk, then upsetting the end of the plunger shank to retain the thrust disk, and finally inserting the first spring, which as noted is simply held by friction.
This invention is not to be construed as limited to the particular forms disclosed herein, since these are to be regarded as illustrative rather than restrictive. It is, there-fore, to be understood that the invention may be practiced with-in the scope of the claims otherwise than as specifically des-cribed.
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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED:

1. In a caulking gun having a frame, a plunger in-cluding a plunger shaft for forwardly urging caulking material, plunger driving means including: a handle, a trigger pivoted to the handle, a first grip and first spring, the first grip biased by the first spring and operable through the trigger for advan-cing the plunger, plunger-pressure retaining means including a second grip and second spring, the second grip biased by the second spring and having a portion operable for releasing plunger pressure, and the plunger having means thereon for manually re-tracting the plunger, the improvement comprising: the first grip encircling within the handle the plunger shaft and having an oper-ative length thereabove proximate the upper portion of the frame, the trigger extending upwardly in the handle to a trigger pivot located above the plunger shaft, a portion of the trigger above the pivot operatively engaging said first grip operative length, and said first spring oppositely biasing said trigger operative engagement.

2. In a caulking gun as recited in claim 1, the han-dle having an open top and said operative engaging of the trig-ger portion with the first grip being proximate thereto.

3. In a caulking gun as recited in claim 2, the han-dle having a forward wall, the first spring being a compression spring, and means for frictionally retaining the first spring in the spacing between the forward wall and the first grip, compris-ing the free length of the first spring being greater than said spacing.

4. In a caulking gun as recited in claim 3, the handle having a rear wall with an opening therein, the second grip within the handle and encircling the plunger with said operable portion projecting through the opening and a rearwardly concave portion extending thereabove to free contact with the rear wall interior, the second spring being on the plunger shaft and urging apart said trigger and second grip.

5. In a caulking gun as recited in claim 4, and means for stopping said trigger advancing of the plunger compris-ing said first spring having a length when fully compressed pro-portioned for stopping advance of said trigger.