WO2013128223A1

WO2013128223A1 - Tool for tightening and releasing screws

Info

Publication number: WO2013128223A1
Application number: PCT/IB2012/000402
Authority: WO
Inventors: Manfred SEIDLER
Original assignee: Seidler Manfred
Priority date: 2012-03-01
Filing date: 2012-03-01
Publication date: 2013-09-06

Abstract

Tight Screws and nuts, even in badly accessible position, can be released or tightened using combination wrenches, when a percussion hammering into its box side is performed. Therefore of the axial movement of a hammer drill is transmitted to a wrench by an axis that fits into the drill's chuck, while its rotation is diverted in a swivel joint in between.

Description

TOOL FOR TIGHTENING AND RELEASING SCREWS

FIELD OF THE INVENTION

The invention relates to a device for fixing and releasing screws in odd positions with an impact type of wrench system, more particularly with applying an impact source to conventional spanners.

PROBLEM TO BE SOLVED

Effective fastening and dismantling screws is best performed with air-hydraulic impact wrenches, widely applied on lug and wheel nuts, where reliable fit has to be combined with reasonable torque for fixing and releasing.

However, on machine brackets and fixtures these air-hydraulic tools are not applicable, since their nuts need to be driven directly from an air-hydraulic motor axis, whereas torque converters or mitre gears do not last long under percussive driving.

Moreover, quite a few screw heads and nuts are concealed by other machine parts and thus hardly accessible, except with a flat spanner.

ASSIGNMENT OF TASK

It therefore is the task of the here disclosed invention to release or fasten these screws or nuts with less effort and risk of breaking the assembly.

PRIOR ART

A quite large number of patents and patent applications refere to impact driving fastening devices, as found in JP2001 -129767, US 4.186.701 and many other constructions of electrical or pneumatic/hydraulically driven impact wrenches.

However, all these instruments refer to driving the screw or bolt in axis without the application of the leaverage from a wrench or spanner and therefore are hardly applicable at screws or nuts, that are concealed by other elements.

There was, however, the invention from M.L.Williams in US 6.748.833 B2, which proposes a tool with a key for nuts, that may be driven by hammering on an impact surface of a hinged arm.

With this construction it is still hard work, whereas the most effective way to set or dismantle tight screws is to apply medium-frequence percussion on the fastening elements, that cannot be achieved with manual hammering. Furthermore, the key and nut system together with the necessary thickness of the transmitting arm demands a clearing above the fastening element, that often enough is not given.

INVENTIVE STEP

The basic finding that leads to the here disclosed solution is, that you can drive a wrench efficiently, if you drill a bore into its flange shortly under the crank of its opposite open end and to press onto it with a pin tap on a rotating hammer drill.

Since this is not a well workable installation, the idea is to make a feasible toolset to work without manually holding the spanner and without taking care of the exact fit between pin and bore.

SUMMARY OF THE INVENTION The wrench therefore is driven by a rod, that on one side is formed as an adaptor to be inserted into the chuck of a conventional rotary hammer drill.

The driving element to the wrench is a clevis bearing on the other end of the rod, that is connected to the shaft or the box part of the wrench, whereas the open end of said wrench is engaged with the screw or bolt that needs to be driven. Since in many cases the revolution of the driving hammer cannot be disengaged, it is absorbed within a pivot bearing in line with the shaft.

PREFERRED EMBODIMENT In a preferred embodiment the wrench is a combination type (that means with one end open and the other end of box type) and the tool consists of a shaft, which on one side comprises an adaptor, that fits into the chuck of the driving means (preferably a SDS = special direct tool adaptor) system. In this SDS adaptor the drill bolting device and torque transmission in SDS is executed separately from each other to be almost wear-free. It works by means of two fac- ing slots (semi-circle cross section), into which in each case one engages to an integrated ball in the bushing.

The opposite end of the shaft is mounted to a clevis bearing. That one may contain a splint, that fits through a bore in the shaft of the wrench. But since this requires some modification on different applicable wrenches, it preferably fits around the box end of the combination wrench, fastened therein with a strong bolt.

The shaft is decoupled from the rotating momentum of the hammer drill by splitting it and applying a pivot bearing between the two halves, preferably therefore a swivel-joint is directly mounted at the clevis bearing. DESCRIPTION OF THE DRAWINGS

Fig. 1 in top view and Fig. 2 in side view show the tool 1 for tightening and releasing screws with a hammer drill, consisting of a swivel connector 2 on a shaft 7 that ends in a SDS-type connector 8 to be inserted into the chuck of the hammer drill.

On the opposite side of swivel connector 2 a clevis bearing 10, consisting of the flanges 15 and 16 encompasses the ring 11 of a combination wrench 12, that preferably has an open- ended wrench element 13 on its other side, which is to be engaged into the nut or bolt, that must be driven. An eye bolt 14 is screwed through an bore on one flange 15 into a thread in the other flange 16 of the clevis to secure this connection.

Fig. 3 shows a longitudinal cut and Fig. 4 a vertical cut of the connector section and demonstrates the swivel function: the fluted shaft 7 enters into the bore 3 of connector 2 to be supported by a ball bearing 4 and secured by holding pins 5 and 6 in his key way 9.

Claims

WHAT IS CLAIMED IS:

1. A tool for tightening and releasing screws with a hammer drill, comprising a shaft, which on one side is fixed in the hammer drill's chuck and the opposite end connected via a swivel joint to a clevis bearing, that fits to a wrench.

2. A tool for tightening and releasing screws as to claim 1 , wherein the swivel bearing is directly mounted to the clevis bearing.

3. A tool for tightening and releasing screws as to claim 1 and 2, wherein the clevis bearing fits around the box part of a combination wrench.

4. A tool for tightening and releasing screws as to claim 3, wherein the box part of the wrench is fixed to the clevis with a strong bolt through the box opening.

5. A tool for tightening and releasing screws as to claim 4, wherein the bolt allows some axial clearance for hammering movement.