IE902742A1

IE902742A1 - Rapid jaw adjustment for tools and the like

Info

Publication number: IE902742A1
Application number: IE274290A
Authority: IE
Original assignee: Petersen Mfg
Priority date: 1989-08-11
Filing date: 1990-07-30
Publication date: 1991-02-27
Also published as: GB2234701A; DK176990A; GB9015370D0; AU5917990A; SE9002366D0; HK25394A; CN1049306A; JPH0398771A; BE1003467A4; IT1246418B; IT9021166A1; NL9001789A; GB2234701B; KR910004310A; DE4024999A1; DK176990D0; SE9002366L; IT9021166A0; BR9003958A; FR2650774A1

Abstract

A fixed jaw 16 is connected to the front portion and a receiving part 32 is located at the rear portion of a fixed handle 12 of a locking tool 10. A movable jaw 14 is pivotally connected to the front portion of the fixed handle 12 for cooperation with the fixed jaw 16. A movable handle 18 is attached to the movable jaw 14. A toggle member 20 has a first end pivotally secured at 22 to the movable handle 18. An adjusting mechanism for adjusting the position of the movable jaw 14 relative to the stationary jaw 16 consists of a threaded opening 38 positioned within the fixed handle, and a screw member 24 having a first end adapted for manual rotation and a second end contacting the second end of the toggle member 20. The screw member 24 and the threaded opening 38 are provided with respective, interengagable multiple threads with the same diameter and pitch throughout the entire length thereof, whereby rapid advancement of the screw member and motion of the jaws relative to each other is accomplished. Embodiments of other tools such as C-shaped clamping tool, chain clamp, welding clamp and sheet metal clamp employing the adjusting mechanism (Figs 6-9) are disclosed.

Description

This invention relates to hand tools, and more particularly to tools utilizing a pair of jaws for receiving a workpiece therebetween.

Common elements of locking pliers, locking wrenches and similar tools employing seme form of locking toggle-actuation are a pair of stationary and movable jaws adapted to lock a workpiece therebetween. A mechanism with an adjusting element acting on the movable jaw is usually provided to adjust a gap between the jaws and to bring them into possible initial contact with a workpiece before huge forces of the toggle action are generated and applied.

The tools of the type presently described are usually used in the circumstances when fast and efficient adjustment of the gap between the jaws is not only highly desirable but absolutely necessary. One example of such use is a conveyor welding operation where a welder has a very short time for adjustment of the tool between welding together two separate pairs of elements having different dimensions. In this situation, it is extremely important to adjust the gap between the jaws of the locking tool to accommodate the dimensions of a new pair of elements as soon as possible.

A known type of prior art device makes such adjustment of a gap between the jaws by means of rotation of a single threaded, single pitch adjustment screw to which the movable jaw is connected directly or indirectly. This method and means of adjustment are necessarily slow and time consuming and result in loss of valuable time in adjusting the tools from one size to another.

The invention accordingly provides a hand tool, comprising a fixed jaw and a movable jaw, a fixed handle having a receiving portion, a screw member engaging with the receiving portion, jaw adjusting means for internal cooperation between the jaws and for adjusting position of said movable jaw relative to said stationary jaw; said screw member having a plurality of first individual and separate threads extending along a longitudinal axis thereof; said receiving portion defined by a threaded opening situated within the fixed handle, said threaded opening having a plurality of second individual and separate threads adapted for threadable engagement with said plurality of the first threads of the screw member; whereby increased rate of advancement of the screw member in the axial direction resulted from rotational engagement of the plurality of said first threads of the screw and the plurality of said second threads of the threaded opening and acting on said jaw adjusting means substantially increases the rate of adjustment of the movable jaw relative to the stationary jaw.

Other advantages and features of the invention are described with reference to exemplary embodiments, which are intended to explain and not to limit the invention, and are illustrated in the drawings in which: Fig. 1 is a side view of long-nose pliers utilizing the invention .

Fig. 2 is a side, partial cross-section view of pliers having curved jaws and utilizing the invention.

Fig. 3 is a partially, enlarged view of a threaded arrangement shown in Figs. 1 and 2.

Fig. 4 is an end view of a screw member.

Fig,. 5 is a partial cross-section view of threads of the screw member.

Fig. 6 shows a partial view of a toggle-locking C-clamp. Fig. 7 is a perspective view of a locking chain clamp. Fig. 8 is a perspective view of a locking welding clamp. 2a Fig. 9 is a perspective view of a sheet metal tool.

Although a specific embodiment of the invention will now be described with reference to the drawings, it should be understood that the embodiment shewn is by way of example only and merely illustrative of but one of the many possible specific embodiments which can represent applications of the principles of the invention. Various changes and modifications, obvious to one skilled in the art to which the invention pertains, are deemed to be within the spirit, scope and contemplation of the invention as further defined in the appended claims.

As best shown in Fig. 1, the long-nose locking pliers is generally designated by the reference numeral 10, and includes a handle member 12, and a movable clamping member or lower jaw 14. The handle member 12 is provided with a stationary clamping element or upper jaw 16. A toggle mechanism comprises an elongated handle member 18 and a toggle-link member 20 which is conventionally pivotally engaged at one end about the pin 22. The other free end (shown in phantom) of the toggle link member 20 is engaged with the handle member 12, and in particular the abutment end (also shown in phantom) of an adjustment screw member 24 which is suitably threadably engaged at the end of the handle member 12. Operation of the screw member will be discussed in full detail later in this application. The forward end of the handle member 18 is preferably bifurcated or forked, and a corner portion of the movable clamping member 14 is suitably disposed within the fork or between the bifurcation arms by pivot pin means 19. Similarly, the handle member 12 is preferably channel-shaped, and receives another corner portion of the movable clamping element 14 which is also suitably secured thereto by means of a pivot pin 17.

Spring means 25, preferably in the form of an extension coil spring, is secured between the handle member 12 and the movable clamping element 14 or lower jaw, to urge the clamping element 14 away from the stationary clamping element when the jaws are opened.

An elongated release lever 28 is suitably pivotally mounted by means of a pin 30, to the inside of the handle member 18, and is provided with a forwardly extending portion (as shown in phantom) and is engageable with a projection 32 of the toggle-like member 20 which^extends toward the handle member 18. When the release lever 28 is pivoted about the pin 30, the handle member 12 is moved away from the handle member 18.

It will be appreciated that the wrench or locking pliers mechanism and toggle construction described herein, with some exceptions, conforms basically in accordance with the construction described in U.S. Patent No. 1,489,458. Furthermore, such construction, the operation thereof, and the specific operation of the release lever is clearly set forth in U.S. Patent No. 3,192,804. As explained in these Petersen prior art patents, closing of a locking wrench or pliers incorporating a toggle device is effected by moving the relatively movable handle member 18 toward the relatively fixed handle member 12. This movement forces the upper end of the toggle-like member 20 to move inwardly towards the handle member 12. The pivot pin 22 also moves inwardly, and when such' pivot pin moves over center, the pliers is locked in a closed position.

A tool of a further embodiment of the invention is best illustrated in Fig. 2 and includes a fixed arm 15 having a fixed handle 12 at one end and a fixed jaw 16 at the other end. A movable jaw 14 is pivotally attached to a movable handle member 18.

The jaws 14 and 16, shown in Fig. 2, are curved and bulky. A toggle-link member 20 is pivotally engaged with the movable handle.

The other free end 44 of the toggle-link engages with a contacting part of a screw member 24. The fixed handle is suitably formed as a U-shaped channel. The end of the fixed handle 30, remote from the fixed jaw 16, is completed with a receiving portion 32 having (£).-0 front 34 and rear 36 parts^. A threaded opening 38 extends through the receiving portion from the part 34 to part 36. A screw member 24 is provided for threadable engagement with the threaded opening. The screw terminates in a knurled adjusting knob 40 at one end and the contacting part 42 at the other end.

When the screw member 24 is turned at the knob by the user, its rotation within the threaded opening results in advancement of the screw in the axial direction. Such advancement in the direction of the fixed jaw 16 presses the contacting part 42 against the toggle-link 20 and changes the distance between the end of the toggle link 4-7 16, whereby the distance between the stationary jaw 16 and the movable jaw 14 is adjusted to grip objects of different dimensions without exerting excessive force.

The screw member 24 and the threaded opening 38 are illustrated in better detail in Fig. 3. A combined threaded part 44 of the screw member consists of two individual, separate and coaxial threads 46 and 48 extending along a longitudinal axis A-A. However, the screw member having any reasonable number of individual threads is within the scope of the invention.

Since the pitches of the threads 46 and 43 shewn in Figs. 35 are identical, the distance between corresponding points on adjacent turns of the thread 46 is equal to the distance between corresponding points on adjacent turns of the thread 48.

Fig. 5 further illustrates that the crest and root diameters of both threads are essentially the same.

To provide adequate threadable engagement between the screw member 24 and the opening 38, the latter has a combined internal thread consisting of two individual, separate and coaxial threads 50 and 52 adapted to threadably engage with the threads 46 and 48 of the screw member. The internal individual threads 50 and 52 extend through the length of the opening 38 from the front part of the receiving portion 34 to the rear part 36.

In the preferred embodiment of the invention illustrated in Fig. 4, two different starting points 54 and 56, at a specific angle apart, are provided for the individual threads of the screw member. This is also applicable to the threaded opening. Although such angle between two starting points could be of any reasonable value, Fig. 4 illustrating an end view of the screw member of the preferred embodiment shows such angle equal 180°.

If the screw member is provided with three individual threads the angle between adjacent starting points could be 120°.

In order to prevent false starts when turning the screw member into the threaded opening, an alternative embodiment (not shown on the drawings) having a single initial or run-on turn is contemplated by the invention. Thus, one thread of the screw member makes initial mating engagement with the corresponding thread of the threaded opening at the beginning of the initial or run-on thread turn of the threaded engagement. Similarly, the second thread of the screw member makes initial mating engagement with the corresponding thread on the threaded opening at the beginning of the same initial or run-on turn. Therefore, only one starting point for two threads is provided in such alternative embodiment.

The threads of the invention could be metric as well as U.S.

Standard threads.

When a single threaded engagement between the screw member and the threaded opening is used, as disclosed by the prior art, the distance which the screw advances axially on one turn of the knob is equal to the pitch of the single thread. On the contrary, if the multiple threaded screw is used, as provided by the invention, the axial advancement of the screw on one turn of the knob is equal to a combined pitch of all individual threads used. The screw member 24 has two individual threads 46 and 48 having corresponding pitches Pl and P2. When the user rotates the knob 40 one full turn, the advancement of the screw in the axial direction is equal to a combined pitch Pl and P2. Such double advancement by the I screw acting on the toggle link substantially increases the rate of adjustment of the movable jaw relative to the stationary jaw.

Fig. 6 illustrates the arms of a toggle-locking C-clamp wherein a fixed clamp member 61 is shown cooperating with a movable clamp member 62, which pivots about the pin 63.

Fig. 7 shows a locking chain clamp, Fig. 8 shows a locking welding c/Λμ^ and Fig. 9 illustrates a conventional sheet metal tool. All tools are well-known in the art and are incorporated by reference .

The above-described arrangements for increasing the rate of adjustment of the movable jaws or similar movable part can be applied to the tools shown in Figs. 6-9.

The adjustment screw arrangement described hereinabove is also applicable for Stilscn wrenches, bench vises and other types of tools.

Claims

1. Claim 1. A hand tool, comprising a fixed jaw and a movable jaw, a fixed handle having a receiving portion, a screw meEber engaging with the receiving portion, jaw adjusting means for internal cooperation between the jaws and for adjusting position of said movable jaw relative to said stationary jaw; said screw member having a plurality of first individual and separate threads extending along a longitudinal axis thereof; said receiving portion defined by a threaded opening situated within the fixed handle, said threaded opening having a plurality of second individual and separate threads adapted for threadable engagement with said plurality of the first threads of the screw member; whereby increased rate of advancement of the screw member in the axial direction resulted from rotational engagement of the plurality of said first threads of the screw and the plurality of said second threads of the threaded opening and acting on said jaw adjusting means substantially increases the rate of adjustment of the movable jaw relative to the stationary jaw. Claim

2. The hand tool as claimed in claim 1, wherein said plurality of said first and second individual and separate threads of said screw member and said threaded opening are two of said first and two of said second threads. Claim

3. The hand tool as claimed in claim 2, wherein said two first and two second threads have identical pitches. Claim

4. The hand tool as claimed in claim 2, wherein said threads are U.S. standard threads. Claim

5. The hand tool as claimed in claim 2 are metric standard threads. wherein said threads Claim

6. The hand tool as claimed in claim 3, wherein one turn rotation of said screw within said threaded opening results in advancement of the screw in the axial direction substantially equal to 1k combined pitch of said threads. Claim

7. The hand tool as claimed in claim 2, wherein starting points of said threads on the screw and the threaded opening are positioned at an angle to each other. Claim 3. The hand tool as claimed in claim 7, wherein said angle is 180°. Claim 9. The hand tool as claimed in claim 7, wherein said starting plane points are situated within the same plane whiclyis positioned substantially perpendicular to the longitudinal axis of the screw. Claim 10. The hand tool of claim 3, wherein said pitches are U.S. standard pitch 14. Claim 11.' The hand tool as claimed in claim 2, wherein each said thread is U.S. standard thread 5/16-13 UMC-2A. Claim 12. The hand tool as claimed in claim 1, wherein said plurality of second individual and separated threads extend through the entire length of the threaded opening. Claim 13. A locking hand tool, comprising a fixed handle having front and rear portions, a fixed jaw connected to said front portion, a receiving part positioned at said rear portion; a movable jaw pivotally connected to said front portion of the fixed handle for cooperation with the jaw, a movable handle connected to the movable jaw; toggle means defined by at least a toggle member having first and second ends, said first end of the toggle link being pivotally secured to said movable handle, adjusting means for adjusting position of the movable jaw relative to said fixed. jaw, said adjusting means comprising a threaded opening positioned within said receiving part of said fixed handle, and a screw member having one end thereof adapted to contact said second end of the toggle member, said screw member having a plurality of first individual and separate threads extending along a longitudinal axis thereof, said threaded opening having a plurality of second individual and separate threads adapted for threadable engagement with said plurality of first threads of the screw member, whereby increased rate of advancement of the screw member in the axial direction resulted from rotational engagement of the plurality of first threads of the screw member with the plurality of second threads of the threaded opening and acting on said movable jaw through said toggle member and toggle means substantially increases the rate of adjustment of said movable jaw relative to said jaw. Claim 14. The hand tool as claimed in claim 13, wherein said plurality of said first and second individual and separate threads of said screw member and said threaded opening are two of said first and two of said second threads. Claim 15. The hand tool as claimed in claim 14, wherein said two first and two second threads have identical pitches. Claim 16. The hand tool as claimed in claim 15, wherein said threads are U.S. standard threads. Claim 17. The hand tool as claimed in claim 14, wherein said threads are metric standard threads. Claim 1

8. The hand tool as claimed in claim 15, wherein one turn rotation of said screw within said threaded opening results in the advancement of the screw in the axial direction substantially equal to tte. combined pitch of said threads. Claim 1

9. The hand tool as claimed in claim 14, wherein starting points of said threads on the screw and the threaded opening are positioned at an angle to each other. Claim 20. The hand tool as claimedtn claim 19, wherein said angle is 180°. Claim 21. The hand tool as claimed in claim 19, wherein said starting points are situated within the same plane which is positioned substantially perpendicular to the longitudinal axis of the screw. Claim 22. The hand tool as claimed in claim 15, wherein said pitches are U.S. Standard pitch 14. Claim 23. The hand tool as claimed in claim 14, wherein each said thread is U.S. Standard thread 5/16-13 UNC-2A. Claim 24. The hand tool as claimed in claim 13, wherein said plurality of second individual and separate threads extend through the entire length of the threaded opening. Claim 25. An adjustment screw for tools and the like, comprising an elongated metal body, a plurality of individual, separate and coaxial threads extending along a longitudinal axis of the body. Claim 26. A locking hand tool substantially as herein described with reference to or as illustrated in the accompanying drawings.