DE1278369B - Attachable screw holder for screwdriver - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

B 25b

German KL: 87 a -19

Number: 1278 369

File number: P 12 78 369.6-15 (G 30455)

Filing date: September 8, 1960

Opening day: September 19, 1968

The invention relates to a screw holder with the screw head which can be plugged onto a screwdriver clamping gripper jaws, each provided with a longitudinal section that rises towards the clamping point are and their ends facing away from the clamping point by a resilient retaining sleeve to the Screwdriver shaft are pressed on, the gripper jaws in the area of their rising longitudinal section are surrounded by a clamping sleeve, which in their position along the screwdriver axis can be changed and presses the jaws inwards.

In a known screw holder for screwdrivers of this type, they become the screw head clamping gripper jaws on the longitudinal section rising to the clamping point by a flat, helical metallic tension spring tensioned. During the clamping process, this must be flat, sharp-edged The spring can be pushed into the tensioned position by hand. This can be done with a larger number of clamping processes lead to finger injuries. The spring is so by its spring force and by self-locking held on the rising longitudinal section of the gripper jaws. Will be with such a screw holder Screws with very different head diameters screwed on so is to maintain the self-locking requires a large length of the screw holder. When screwing Such screws are of the use of the screw holder because of the low extensibility There are limits to the flat metal spring. Because as soon as the spring when tensioning a large screw If the screw is overstretched, the spring preload is sufficient to hold the screw of smaller diameter no longer off.

The invention has for its object to provide a screw holder for screwdrivers of the initially to create the type described, which is an easily actuated and not over-rotated when tensioning Has tension spring and is suitable for screw heads of very different diameters.

This object is achieved according to the invention in that the clamping collar is made of a rubber-elastic The material is an existing ring that is used to clamp or relax the gripper jaws Projections can be rolled, which are located on the longitudinal sections of the backs that rise towards the clamping position of preferably the same gripper jaws injection-molded from plastic.

It is known per se to provide wave-shaped projections on the back of gripper jaws. However, these projections represent a thread, the threads of which are spring windings of an attachable screw holder
for screwdrivers

Applicant:

Hans-Theodor Grisebach,
4628 Lünen, Münsterstr. 16

Named as inventor:

Hans-Theodor Grisebach, 4628 Lünen

Pick up coil spring. However, this helical spring, which is used as a clamping collar, is not rollable. Your change in position for tensioning or relaxing is done by twisting in the circumferential direction of the screw holder. Such an adjustment is compared to the subject of the application laborious.

According to a further embodiment of the invention, the rising longitudinal sections of the gripper jaws run into parallel end pieces, which have inwardly directed claws at their ends, the seen in longitudinal section are wedge-shaped.

In order to give the rubber a good grip, i.e. to prevent it from rolling back, one of the Further development according to the invention, the projections formed like a sawtooth, so that the clamping Required rolling movement of the cuff over flat and the rolling movement required for loosening takes place over steep angles of inclination of the projections.

According to a further embodiment of the invention, the gripper jaws carry on from the clamping point remote ends with spaced cams, ribs od. The like. Used as stops for the Serve retaining sleeve, which are also parallel in the axial direction and transversely thereto and are less due to zones Wall thickness are separated from each other, so that the gripper jaws are attached to the screwdriver shaft can adjust better under the tension of the retaining cuff.

For better elasticity of the gripper jaws, according to a further embodiment of the invention, these Have gripper jaws at the beginning of the rising longitudinal section recesses. Go there these recesses expediently from the longitudinal edges of the gripper jaws. Between the-

809 617/181

sen recesses and the cams behind them is according to a further embodiment of the invention there is a spacing provided for the rear end position of the clamping collar, the at least corresponds to the width of this cuff.

Since the retaining sleeve is shortened in the tensioned state, after a further training of the invention, the retaining sleeve in the relaxed state is slightly longer than the clear distance between the cams.

The drawing shows a perspective view of the screwdriver shaft with the two gripper jaws as well as the elastic clamping sleeve and the rubber band.

On a screwdriver shaft 20, which may have different diameters, are held together by the rubber sleeve 2 (retaining sleeve) and pressed against the shaft 20 Slid on parts that are injection-molded from plastic and form gripper jaws 3 with sleeves 1. In ao the position shown, the gripper jaws 3 grasp with their hook-shaped ends (claws 6) a Screw head, in whose slot the shown cutting edge of a screwdriver end engages. Through this the screw is held in the screwed-in position. The gripper jaws 3 are through a Rubber ring 4 (clamping sleeve) held under tension so that the claws 6 firmly hold the screw head capture. The rubber ring preferably has a profiled, for example polygonal, cross section. This makes it easier for him to stay in the chosen position.

Between the collars 1 and the clamping point of the screw, longitudinal sections 7 rising towards the clamping point are provided on the gripper jaws 5, on the outside of which projections 8 are arranged. These projections 8 are preferably wave-like and / or sawtooth-like in such a way that they have flat-angled sliding surfaces in the tensioning direction and steep-angled sliding surfaces with corresponding angles of inclination 9, 10 in the relaxation direction. The rubber ring 4 should thus be able to be rolled easily into the tensioned position over the projections 8, but more difficultly into the relaxed position. Inwardly directed wedge-shaped claws 6 are provided at the ends of the gripper jaws. With the help of the wedges, the claws are automatically pressed outwards during the screwing-in process, so that the screw holder detaches from the screw head.

The rubber sleeve 2 drawn onto the sleeves 1 lies on the one facing away from the clamping point Ends 13 of the gripper jaws and is between the cams 14 and 17 against longitudinal displacement secured. The rubber sleeve is slightly longer than the clear dimension between the cams 14 and 17, so that, in the stretched state, the gripper jaws 1 are also adequately protected against longitudinal displacement secures. It is advantageous if the cams 17 and 14 are so high that they are beyond the strength of the rubber sleeve 2 protrude and provide support for the operator's finger. Is the rubber ring 4 rolled up to the distance 19, the gripper jaws 3 are spread due to their internal bias. The screw holder can then be placed on a new screw or on the shaft of the screwdriver20 be pushed back up to the handle; the latter if a screw holder is not required will.

Through the recesses 18 at the transition from the cylindrical part of the sleeves 1 and the longitudinal sections 7, a smaller wall thickness is achieved, as a result of which the gripper jaws 3 are more elastic is achieved. The gripper jaws 3 should be as stiff as possible. There are therefore stiffening ribs 21 inside and / or provided outside.

From the longitudinal edges 16 of the gripper 3 can cams or cams in a manner not shown Tabs go out, the od in a correspondingly profiled recess. Like. On the oppositely directed Engage the longitudinal edge of the adjacent cuff part to provide additional security To create cuffs to each other against relative movements in the longitudinal direction. The two made of plastic Injected gripper jaws should, if possible, be parts of the same design. However, it is conceivable that they can also be somewhat different without the advantages of the invention being lost.

Thus, on the top and / or bottom of the cylindrical sleeve parts 1 sharp-edged ribs Od. The like. Be provided so that the clamping collar 2 slips with respect to the screwdriver shaft 20 is prevented.

Claims (9)

Patent claims: 1. Clamp the screw holder that can be slipped onto a screwdriver with the screw head Gripper jaws, each provided with a longitudinal section that rises towards the clamping point are and their ends facing away from the clamping point by a resilient retaining sleeve are pressed against the screwdriver shaft, with the gripper jaws in the area their rising longitudinal section are surrounded by a clamping sleeve, which is in their position can be changed along the screwdriver axis and presses the jaws inwards, characterized in that that the clamping collar is a ring (4) made of elastic material, which is used for tensioning or relaxing the gripper jaw can be rolled over projections (8) which rise towards the clamping position Longitudinal sections (7) of the backs of preferably identical, injection-molded plastic Gripper jaws (3). 2. Screw holder according to claim 1, characterized in that the rising longitudinal sections (7) the gripper jaws run out in parallel end pieces (5), which at their ends after have inwardly directed claws (6) which are wedge-shaped seen in longitudinal section. 3. Screw holder according to claim 1, characterized in that the projections (8) are sawtooth-like so that the rolling movement of the cuff (4) required for tensioning is flat and the rolling movement required for loosening The projections (8) take place via steep angles of inclination (9, 10). 4. screw holder according to claim 1, characterized in that on the of the clamping point facing away ends (13) of the gripper jaws these at a distance from cams, ribs (14, 17) or the like. wear, which serve as stops for the retaining sleeve (2), which also in the axial direction and transversely lie parallel to this and are separated from one another by zones of small wall thickness (15), see above that the gripper jaws (3) are attached to the screw can better adjust the puller shaft under the tension of the retaining sleeve (2). 5. screw holder according to claim 1, characterized in that at the beginning of the rising Longitudinal section (7) in each gripper jaw (3) recesses (18) are embedded. 6. screw holder according to claim 5, characterized in that the recesses (18) of the longitudinal edges of the gripper jaws go out. 7. screw holder according to claim 4 and 6, characterized in that between the recesses (18) and the cam (17) behind it for the rear end position of the Clamping collar (4) provided spacing (19) is present, which is at least the width of this Cuff corresponds. 8. Screw holder according to one of claims 1 to 7, characterized in that the holding sleeve (2) when relaxed is slightly longer than the clear distance between the cams (14 and 17). 9. screw holder according to one of claims 1 to 8, characterized in that the for the Holding sleeve (2) provided support surfaces in the longitudinal direction with parallel, preferably sharp-edged ribs are provided. Considered publications:
German utility model No. 1723 999;
French Patent No. 1145 069;
British Patent No. 4518/1875;
U.S. Patent No. 1764,504. 1 sheet of drawings 809 617/181 9.68 © Bundesdruckerei Berlin