The present invention generally relates to tools and particularly adjustable locking levers for such tools.
It is known to users of tools that it is often necessary during use to lock tool components in a particular position such as the depth of cut of a plunge router or circular saw or the bevel angle adjustment of a circular saw among many other applications. Through the life of the tool, users often find that the locking components experience wear, which requires a lever to be rotated further to achieve the same locking force. At some point, the lever will interfere with another component external to the locking system, such as a motor housing, a foot of a saber saw or circular saw, among other examples, which prevents the locking lever from being adequately tightened. In prior art systems, the user has been forced to index the lever back to a different position to enable the system to be fully tightened.
Prior art systems in commercially available professional saws have required the removal of a screw or retaining ring to reposition the locking lever. In addition to being inconvenient, there is the prospect of possible loss of the retaining ring or screw. Other tool-less locking and unlocking devices have comprised wing nuts or knobs.
While prior art adjustable lever systems exist which have a lever that can be moved outwardly against the force of a biasing spring from its normal position so that it can be repositioned at a different angle that enables the system to adequately tighten the desired components, these systems generally have required a nut that engages a carriage bolt or the like and another screw that is threaded into the opposite end of a hex head adjusting nut to retain a spring in position that biases the handle into engagement with the hex headed adjusting nut.
It is a goal of the present invention to provide a universal locking lever that has a simpler design that is also easy to assemble in a tool in which the lever may be used.
A preferred embodiment of the present invention has a universal locking lever system that has a lever in which an adjustment nut is inserted, a carriage bolt or the like which is threaded into the adjusting nut, a spring that has one end bearing against a shoulder in the lever and the opposite end bearing against an end cap, the end cap being configured to snap fit in locking position to the adjusting nut during assembly.
The preferred embodiment of the universal locking lever is shown in the drawings and is useful for locking tool components, such as routers, saber saws, jigsaws and circular saws, as well as in other applications than in the hand tool art. However, the preferred embodiment is particularly suited for use in circular saws such as the circular saw shown in
The universal locking lever assembly 10 is shown in the exploded view of
Corrugations 44 or other texturing may be provided to facilitate gripping of the lever arm 24 during use. The adjusting member 26 has an opening in its right end face 46 that preferably includes an internal thread. The adjusting member 26 further includes an end portion configured to engage the preferred double hex configuration 40, preferably a hex head portion 48, and a cylindrically shaped opposite end portion 50 around which an annular groove 52 is disposed. Other embodiments of the invention include an end portion that is shaped to be a plurality of configurations, such as square, pentagonal, spline, or others, such that the end portion is configured to lockingly engage the double hex portion 40 or other corresponding mating configuration. Preferably, an end surface of the opposite end portion 50 includes a slot 51 or other configuration to allow the user to precisely rotate and/or thread the adjusting member 26 to the threaded fastener 28, which extends from a portion of the saw to engage the adjusting member. The biasing member 30 may have a uniform diameter along a length thereof, but in the preferred embodiment, includes a smaller diameter end 54 and the spring increases in size to the larger end portion 56.
The end cap 32 is shown in detail in
Thus, as illustrated in
When coupled to the saw, the assembled locking lever 10 may be rotated in either a clockwise or counterclockwise direction to either tighten or loosen the threaded engagement of the threaded fastener 28 and the right end face 46 of the adjusting member 26. Additionally, where slippage and wear creates a situation where the lever arm 24 does not effectively tighten or loosen the engagement because another component external to the locking system interferes, the instant invention provides for quick readjustment of the hex head portion 48 within the double hex configuration 40 of the cylindrical portion 36. More specifically, the user only needs to simply pull out the lever arm 24, which causes the biasing member 30 to compress and the hex head portion 48 to disengage from the double hex configuration 40, at which time the user may reorient and readjust the position of the lever arm 24 to eliminate the interference. Once the user has repositioned the lever arm 24, the user simply releases the lever arm, and the biasing member 30 causes the hex head portion 48 to re-engage the double hex configuration 40 in the readjusted position.
One alternative embodiment of the locking lever assembly 10 illustrated in
While various embodiments of the present invention have been shown and described, it should be understood that other modifications, substitutions and alternatives are apparent to one of ordinary skill in the art. Such modifications, substitutions and alternatives can be made without departing from the spirit and scope of the invention, which should be determined from the appended claims.
Various features of the invention are set forth in the following claims.
This application claims the benefit under 35 U.S.C. §119 of U.S. Provisional Application No. 60/537,269, filed on Jan. 16, 2004.
Number | Name | Date | Kind |
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5020407 | Brinlee | Jun 1991 | A |
5307566 | Matzo | May 1994 | A |
5570610 | Cymbal | Nov 1996 | A |
Number | Date | Country |
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681361 | Mar 1993 | CH |
Number | Date | Country | |
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20050155232 A1 | Jul 2005 | US |
Number | Date | Country | |
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60537269 | Jan 2004 | US |