DE1110580B - Freewheel wrench with torque limiter - Google Patents

Description

The invention relates to a torque limiting freewheel wrench, in particular for the operation of the clamping screw connections of pit punch friction locks, for example clamping ring locks. By using such keys all punches that are used in the same mining strut should be as similar as possible Load capacity can be set.

Freewheel wrenches with torque limitation are already available in different designs known. A torsion bar with pointer reading or is used to limit the torque in these designs Release mechanism, a type of multi-plate clutch or helical gears working against spring pressure od. Like. In addition to such freewheeling wrenches with various types of torque limitation are also screwdrivers with a device for determining a desired maximum tightening torque known in the form of an adjustable tension band.

The known freewheeling wrenches with torque limiting mentioned are mainly has been developed for the needs of the machine industry. You may like for this and similar uses be suitable, as they are mostly used there by appropriately trained people, who handle and maintain these keys properly.

Completely different conditions exist in underground mining operations, if only because the miner, not to mention the poor space and visibility, with his toughness and other tools, experience has shown, tends to handle rough. For this reason, freewheel wrenches must be used with a torque limiter that you put in your hand, robust and not very sensitive be against pollution. The keys must be particularly easy to clean and adjust. In the known, relatively complex designs, this is not or only inadequately the case Case, so that these are poorly suited for rough mining operations.

Keys with visual or acoustic signals are underground due to the prevailing conditions there unusable. Keys that release jerkily should also be avoided as they cause the Screw connections of friction locks on pit punches to apply considerable forces of up to 20 mkg and more are. A swap from hub to hub must also be avoided in order to achieve a quick To enable setting or robbing the stamp.

To get the aforementioned Fot freewheel wrench and others
with torque limitation

Applicant:

Karl Gerlach and Dr.-Ing. Hans Gerlach,
Moers (Ndrh.), Hornberger Str. 86

Karl Gerlach and Dr.-Ing. Hans Gerlach,

Moers (Ndrh.),
have been named as inventors

changes that underground operations in particular place on a freewheel wrench with torque limitation,

ao as far as possible to comply, it is proposed according to the invention, a known per se To use a freewheel wrench with a tightening strap entrainment effect and to design it so that the entrainment effect the tightening strap can be limited adjustable, so the freewheel key to a those with torque limitation will be.

The invention is based on a freewheel wrench with a tightening strap, one end of which is at the as Lever serving key handle is hinged and the other, free end when pivoting the Key handle in the driving direction through an approach provided on it to the hinged end of the strap is approached. In order to solve the problem posed, such a freewheeling key is according to of the invention at the ends of the tensioning band their approaching movement and thus the transferable Arranged torque-limiting adjustment means or deposits. This allows the strap clamped around the object to be twisted only with a certain, limited, adjustable tension will. As soon as the torque to which the tensioning strap is set is exceeded the key slips.

For this purpose, a stop screw is advantageously arranged at the hinged end of the tensioning strap, which is adjustable against the free end of the strap.

The inner surface of the strap is expediently secured against abrasion and corrosion. This can be especially can be achieved effectively by hard chrome plating. It is easily possible to use the invention

.,. according to the key with its tightening strap

109 620/69

10

bar on the part of the screw connection to be rotated. This part must then be cylindrical Have external surface. It is also important to ensure that all parts to be rotated are exactly the same Have the same diameter and surface finish in order to be able to use the key - as intended - also absorb the same torque. In the case of pit punches, for example, this is suitable the arrangement of a union nut as a clamping device for the screw connection.

It can also be advisable to take the freewheel wrench with you in a manner known per se to provide a cylindrical insert with a twisting square or a so-called key nut. A Such an insert is expediently made of corrosion-resistant material with a high coefficient of friction. In addition the alloys known from friction inserts for pit punches are particularly suitable, for example Copper-silicon alloys with manganese or nickel added. But the key could also come from Made of plastic, for example from a polyamide.

An exemplary embodiment of the invention is shown schematically in the drawing. It shows

Fig. 1 is a plan view of a key according to the invention,

2 and 3 longitudinal sections parallel and perpendicular to the key plane.

On the handle 4 of the wrench, a tensioning strap 1 is closed by means of a bolt 3 an eyelet formed end 2 articulated. The other, free end 6 of the tensioning strap 1 is nose-like thickened. The key handle 4 lies with the working stroke in the direction indicated by an arrow an approach 5 against the nose-like thickened trained, free end 6 of the tensioning strap 1 and tensioned the band, i.e. the space enclosed by the tension band 1, is narrowed.

In the clamping band 1 is a cylindrical key nut 7 with a square opening 8 for the reception an insert 9, which carries a retaining collar 10 and has square plug pins 11 and 12. The insert 9 is held in the tensioning strap 1 by a counter disk 13 and a nut 14.

On the freewheel key is finally a stop screw 15 with adjusting head 16 and lock nut 17 provided, which limits the approach of the strap ends 2 and 6 adjustable, so that the Freewheel wrench becomes one with torque limitation.

In order to make this key even more useful for the interests of underground operations, the Inner opening of the tension band 1 hard chrome-plated. The key nut 7 consists of a corrosion-resistant Metal alloy with a high coefficient of friction or made of plastic. The parts 7 to 12 stored in the tensioning band 1 can also be made in one piece. But you can also omit if the strap 1 is immediately is placed on the part to be rotated.

Claims (4)

PATENT CLAIMS: 1. Freewheel wrench with a strap, one end of which is hinged to the key handle serving as a lever and the other, free end when pivoting the key handle in the driving direction is approached by a provided on it approach the hinged strap end, characterized in that at the ends (2, 6) of the tensioning band (1) their approach movement and thus the transferable torque limiting adjustment means (15, 16, 17) or inserts are arranged. 2. freewheel wrench according to claim 1, characterized in that on the articulated At the end (2) of the tensioning band (1) a stop screw (15, 16, 17) is arranged, which against the free end of the strap (6) is adjustable. 3. freewheel wrench according to claim 1 or 2, characterized in that the inner surface of the strap (1) is hard chrome-plated. 4. freewheel wrench according to spoke 1, 2 or 3, characterized in that the key nut (7) is made of corrosion-resistant material with a high coefficient of friction. Considered publications:
German Patent No. 802508;
British Patent No. 393 243. 1 sheet of drawings Q 109 620/69 6.61