DE20217684U1 - Foldable wheel nut wrench/spanner has fold-out grip arm extension forming long lever arm to release screw connection, short lever arm to tighten screw - Google Patents

Abstract

The wrench has a grip with fold-out extension (B). A lever arm (A) has a joint (DG) on the grip side, with an axis parallel to the pivot axis of the screw connection (DS) to be fastened/released. The joint locks the fold-out extension on the grip, so that in extended position in moves in one direction only, to release the screw connection. The extension may be located inside the grip and locked on the inner base of the grip when turned outwards.

Description

Gudrun Hudel

Peter Hudel

Nice view 1

61169 Friedberg

Reference number 202 17 684.3

Utility model: Folding wheel nut wrench, Folding wrench
Description:

The present invention relates to a handle (lever arm) for rotary tools for loosening and tightening screw connections. Previously known handles have either a constant handle length or a variant handle length using a telescopic handle.

The known solutions have the following disadvantages. Due to external influences such as corrosion, screws must be loosened with a higher torque than they were fastened. This is very difficult to achieve with a handle (lever arm) with a constant handle length. The best example of this is wheel nut wrenches. How difficult or almost impossible is it to loosen wheel nuts with a conventional wheel nut wrench with a constant handle length? There are two other disadvantages with a telescopic handle. Due to the handle extension, which also works when fastening the screw, the screw can easily be damaged when tightening. The head shears off or the thread is damaged. The other disadvantage is the high manufacturing costs of the telescopic handle.

The invention of the fold-out handle (lever arm) is intended to meet the requirements for tightening and loosening screw connections described above with this special handle, which is inexpensive to manufacture. This handle has a short lever arm for fastening the screw connection and a long lever arm for loosening the screw connection. The fact that the long lever arm only works to loosen the screw connection is ensured by the arrangement of the axis of rotation between the two lever arms and a corresponding locking mechanism between the handle elements.

The invention consists in the handle (lever arm) having another fold-out handle (lever arm). The axis of rotation that connects the two handles (lever arms) to each other is parallel to the axis of rotation of the screw connection to be loosened or fastened at the other end of the lever arm. The fold-out lever arm rotates out of the lever arm in the direction of rotation to loosen the screw and locks at the stop of the lever arm. This ensures that the handle extension only works in the direction of rotation to loosen the screw connection. A second fold-out lever arm could be implemented within the fold-out lever arm using an identical concept.

The structural design can be implemented in two variants, in addition to the variants for right- and left-turning screws.

Variant 1 is that the fold-out lever arm is located in a U-profile of the lever arm. Variant 2 is that the fold-out lever arm itself is a U-profile and is located above the lever arm.

The accompanying drawings illustrate some embodiments of the invention.
The embodiment 1 is a lever arm (A) with a fold-out handle extension (B). The lever arm (A) consists of a U-profile. The connection between the lever arm (A) and the handle extension (B) is a swivel joint (DG) that is arranged parallel to the axis of rotation of the screw (DS). The U-profile of the lever arm (A) and the swivel joint (DG) are structurally arranged in such a way that the handle extension (B) only acts to release the connection around the pivot point (DS). The handle extension (B) is locked at the base (AS) of the U-profile of the lever arm (A).

The advantage of this solution is that when tightening the screw connection around the pivot point (DS), no extended lever arm is available. This means that the thread cannot be damaged when tightening the screw connection during normal use. The extension of the lever arm only works when the screw connection is loosened. This means that screws that were fastened with this lever arm can be safely loosened with this lever arm.

Typical areas of application are screw connections which, for example due to corrosion and other external influences in the phase between fastening and subsequent loosening, result in a higher torque being required to loosen the screw connection.

Claims (5)

1. Handle with fold-out handle extension for fastening and loosening screw connections, characterized in that the lever arm (A) on the handle side is equipped with a joint whose axis runs parallel to the axis of rotation of the screw connection and the fold-out handle, in the unfolded state, is locked to the handle A in only one direction of rotation for loosening the screw connection. 2. Referring to claim 1, there is a variant for right-hand threads in which the fold-out handle locks in the anti-clockwise direction of rotation when unfolded. 3. Referring to claim 1, there is a variant for left-hand threads in which the fold-out handle locks in the clockwise direction of rotation when unfolded. 4. With reference to claim 1, the structural design can be realized in such a way that the fold-out handle extension is attached to the handle and locks into place on the inner base of the handle when unscrewed. 5. With reference to claim 1, the structural design can be realized in such a way that the fold-out handle extension is attached above the handle and, when unscrewed, locks on the floor on the opposite side of the handle.