US 3882753 A
A speed wrench tool for rapid one-handed tightening of threaded fasteners. At one end the tool is terminated by a fastener-engaging socket which is pivotally attached for articulation to the end of a long arm member having a free-turning grip at the other end. Proximate the grip end the arm member has a pair of zig-zag bends, a first bend at an acute angle away from its longitudinal axis and a second bend at an acute angle back towards the axis so that, in use for low torque applications, the longitudinal axis of the arm member may be aligned collinearly with the longitudinal axis of the fastener and turned rapidly by wrist swiveling action alone. For higher torque in the final tightening of the fastener the arm member can be pivoted perpendicularly to the axis of the fastener so as to provide a long moment arm.
Claims available in
Description (OCR text may contain errors)
United States Patent 1 Svensen I SPEED WRENCH TOOL Charles R. Svensen, Rt. 2, Box 92, Philomath, Oreg. 97370  Filed: Oct. 18, 1973  Appl. No.: 407,644
Primary Examiner-Al Lawrence Smith Assistant Examiner-James G. Smith Attorney, Agent, or Firm-Chernoff & Vilhauer  ABSTRACT A speed wrench tool for rapid one-handed tightening of threaded fasteners. At one end the tool is terminated by a-fastener-engaging socket which is pivotally attached for articulation to the end of a long arm member having a free-turning grip at the other end. Proximate the grip end the arm member has a pair of zig-z ag bends, a first bend at an acute angle away from its longitudinai axis and a second bend at an acute angle back towards the axis so that, in use for low torque applications, the longitudinal axis of the arm member may be aligned collinearly with the longitudinal axis of the fastener and turned rapidly by wrist swiveling action alone. For higher torque in the final tightening of the fastener the arm member can be pivoted perpendicularly to the axis of the fastener so as to provide a long moment arm.
2 Claims, 2 Drawing Figures PATENTEQ HAY l 313? FIG. I
SPEED WRENCH TOOL BACKGROUND OF THE INVENTION securing nuts in order to avoid wasting time. It would be desirable to use a wrench which would enable rapid turning of a nut when it is loose yet would provide considerable torque when the nut becomes tighter. It would be particularly desirable to have such a wrench which would leave one of the mechanics hands free to perform other tasks during the tightening process, such as starting the remaining nuts on their respective bolts.
Wrenches which permit rapid tightening of threaded fasteners are known to the art but they do not permit maximum utilization of the vmechanics time. Some L- shaped wrenches, Klang U.S. Pat. No. 3,388,622 for example, and U-shaped wrenches require one hand to stabilize the wrench and the other to turn it, therefore preventing the mechanic from performing any other task with his hands at the same time. Two-handed operation may be overcome in low torque situations by a balanced T-shaped wrench, for example Walters US. Pat. No. 1,433,163, but two hands are still needed where greater torque is required and the amount of torque that may be applied is limited by the moment arm, defined by one-half of the length of the top of the T, which must be short to permit rapid turning at low torque. One-handed operation may be provided with an L-shaped wrench, such as Bidal US. Pat. No. 1,741,810, if the short side of the L is collinear with the longitudinal axis of the fastener and the long side provides the moment arm to develop sufficient torque; however, the long moment arm prevents rapid turning when the fastener is fairly loose and requires relatively little torque. A speed wrench now in common use comprises a socket head pivotally coupled to a long straight arm; this arrangement permits one-handed use and variation of the moment arm, but rapid turning cannot be achieved by wrist action alone.
SUMMARY OF THE PRESENT INVENTION The present invention overcomes the aforementioned deficiencies of prior art speed wrenches by providing a tool requiring only a single hand to use which is manipulated in one position when only low torque is required to permit rapid turning of a fastener, and is quickly adjustable to another position when high torque is required to provide a long moment arm. The tool consists of a socket head adapted to engage the fastener and pivotally mounted for articulation to one end of a long arm member. The arm member is provided with a free-turning grip at the other end and has a pair of zig-zag bends therein, the first bend being angled away from the longitudinal axis of the arm and the second being angled back towards the axis of the arm so that in gripping the end of the arm the wrist of the user is aligned with the main longitudinal axis of the wrench arm member. At low torque the arm is aligned collinearly with the longitudinal axis of the fastener and can be rapidly turned by swiveling wrist action alone. When high torque is needed the arm is pivoted about the socket so that its axis is toward the perpendicular to the axis of the fastener, providing a long moment arm. This dual-mode of operation permits rapid onehanded tightening of threaded fasteners.
It is therefore a principal objective of the present invention to provide a novel and improved speed wrench tool for rapid one-handed tightening of threaded fasteners.
It is a principal feature of the present invention to provide a speed wrench tool for rapid tightening of threaded fasteners which can be operated with a single hand in quickly interchangeable positions, one position permiting rapid turning of the threaded fastener by wrist action alone and the other position providing a long moment arm useful for producing great torque in the final tightening of the fastener.
The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of the speed wrench tool of the present invention.
FIG. 2 is a side view of the speed wrench tool rotated about its longitudinal axis from the poistion shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, an arm member 10 articulates a socket head holder 12 by pivotal joint 14 at one end and near the opposite end has a first bend 16 of a pair of zig-zag bends at an obtuse angle 0 to the included axis of the arm, a second bend 18 at an angble d) to the axis formed by the first bend and located a distance x from the first bend, and then followed by a grip 20 located at a distance y from the second bend. The socket head holder 12 is designed to releasably secure by a spring-biased detent 24 a socket head 22, selected from a set of various sizes, for engaging a threaded fastener such as a bolt head or nut.
The first bend l6 and the second bend 18 in the arm member 10 are placed in positions and form angles such that the arm member 10, upon being grasped by the grip, can be rotated almost entirely by wrist action alone when its longitudinal axis 26 is collinear with the longitudinal axis of the threaded fastener. When the speed wrench is in use in a low torque situation, the forearm of the operator is approximately collinear with the axis 26 of arm member 10, the end of arm member 10 touches the heel of the operators hand and the grip 20 rests comfortably in the hand when it is in a natural position. Since the grip 20 angles away from the axis 26 of the arm member 10, there is a greater moment arm provided for the force applied along the grip by the operators hand than if the arm member 10 were straight. When the wrench is rotated, the operators forearm remains nearly stationary while his hand rotates on his wrist joint in a roughly circular path. In an arrangement found to be particularly suitable, the first bend 16 in the arm member makes an obtuse angle 6 of approximately from the axis 26 and the distance x between the two bends is about 2% inches long. The second bend 18 is at an angle (11 of approximately 97 from the extended axis 28 formed by the first bend, and the grip end extends a distance y of about 6 inches to the end of the grip. These dimensions place the center of the end of grip 20 substantially coincident with the longitudinal axis 26 of the arm member. While these angles and spacings have been found suitable, other bend dimensions may be utilized to accomplish the same functional objectives discussed above.
Grip 20, mounted on the end of the arm 10, comprises a free-turning handle such as a knurled sleeve 22 concentrically mounted for rotation on arm 10. It might also be feasible to employ a fixed grip 20 formed from the end of the arm member rather than a freeturning handle; however, in the latter case the users hand would soon become sore from rubbing against the surface of the grip as it is rotated.
In order to provide a long moment arm in high torque situations, as occurs in the final tightening of a fastener, the pivotal joint 14 permits, as shown in FIG. 2, the arm member 10 to pivot approximately 90 in either direction from the longitudinal axis of the socket head 22, the pivot axis 30 being in the plane formed by the arm axis 26 and the zig-zag bends 16, 18. (Alternatively, the speed wrench could be designed with the pivot axis 30 perpendicular to this plane in order to provide an adjustable moment arm for increasing torque as the fastener becomes tighter. In such case the wrench could be swiveled to an intermediate position between the two limits and rotated along a conical path by a combination of wrist and arm movement, the slope of the cone determining the length of the moment arm. However, in this alternate arrangement, when the wrench is not pivoted to near the perpendicular, the applied force tends to cause the wrench to rotate about the axis 26 of the arm member, producing disengagement of the socket head 22 from the fastener and awkwardness in use.)
In use, when a fastener such as a nut on a bolt is first started, it requires very little torque. Accordingly, the speed wrench would initially engage and turn the fastener nut with its axis 26 aligned collinearly with the longitudinal axis of the bolt. In this fashion the nut can be tightened down very rapidly with one hand by a circular wrist action of the operator as he holds the grip 20. When the nut becomes too tight to turn rapidly with circular wrist action alone, arm member 10 may be quickly swiveled 90 on the pivot axis 30, and again with the same single hand, the nut firmly tightened with the sizeable moment arm obtained by rotating grip in a circular path about the longitudinal axis of the socket head 22. Thus the entire fastening operation can be performed with one hand, leaving the remaining hand free for other tasks.
Although an exemplary apparatus and application has been disclosed and discussed, it should be understood that the example used is not set forth as a limitation on the scope of the invention, and other applications and mechanical configurations may also utilize the concepts and principles of this invention. Accordingly the terms and expressions which have been employed in the foregoing abstract and specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.
What is claimed is:
l. A speed wrench tool for single-handed rapid tightening of threaded fasteners by rotation thereof comprising a generally longitudinally-extending arm memher, head means for releasably engaging a threaded fastener, coupling means for pivotally connecting said head means to an end of said arm member by a pivot axis permitting said arm member to be pivotally articu lated between a position substantially collinear with the axis of rotation of said fastener and a position at substantially thereto, an elongate grip handle at the other end of said arm member, and a zig-zag pair of coplanar bends in said arm member near the grip handle end thereof so as to present said grip handle end at an acute angle with and terminating proximate to the extension of the longitudinal axis of said arm member, said pivot axis of articulation being substantially in the plane defined by said pair of bends, whereby said grip end may be grasped and said arm member initially aligned substantially collinear with the axis of rotation of said fastener for rapid axial rotation and tightening of said fastener substantially by a wrist action alone, and said arm member thereafter pivoted substantially 90 therefrom for applying relatively high torque to complete the tightening of said fastener.
2. A speed wrench tool as recited in claim 18 wherein said elongate grip handle comprises a generally cylindrical, free-turning handle mounted for rotation on said grip handle end.
UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,882,753
DATED May 13, 1975 |NV E NTOR(S) Charles R. Svensen It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Col. 2, line 36 Change "angble" to -angle.
Col. 4, line 44 Change "claim 18" to -claim l-.
Signed and Scalcd this ninth Day of December 1975 '[SEAL] Attest:
RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner ufParents and Trademarks