JPS63312079A - Power screw driving head section - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention comprises a shaft, a screwdriver piece connectable to the shaft, a screwdriver piece supported by the shaft, and a sleeve for machining the shaft by applying a preload to the sleeve. A coil spring movable in the axial direction on the workpiece end and a restraining ball provided between the screwdriver piece and the sleeve to a depth that allows the sleeve to cut onto the surface of the workpiece. Constructed as a stopper sleeve 1,
The shaft has, at its end near the workpiece, a seat with a circular cross-section, and this seat has a radial hole that accommodates a restraining ball so that it can be moved in the direction of a lateral force; The recessed portion of the sleeve with a smaller diameter is transmission coupled to the screwdriver piece at the position, and the recessed portion of the sleeve with the larger diameter is located at a position offset in the axial direction with respect to the recessed portion with the smaller diameter. This invention relates to a power screwdriver head that releases a screwdriver piece at a release position where a restraining ball enters a recessed portion.

[Conventional technology]

Such a screwdriver head is disclosed in Patent No. 28 of the Federal Republic of Germany.
It is known from US Pat. No. 4,287,923 that the screwdriver head is automatically uncoupled when the screw reaches a certain screw-in depth. In this known device, once the screw has been inserted into the workpiece, it is not possible to remove it, even if the direction of rotation of the IM driver is reversed. In practice, however, it is necessary to remove the inserted screw, for example if the screw is inserted in the wrong place or if the parts connected by the screw have to be separated again.

[Problem that the invention seeks to solve]

The object of the invention is to improve this known device so that the inserted screw can be easily removed using simple and reliable means.

[Means for solving problems]

In order to solve this problem, according to the invention, the smaller diameter recessed part is divided into two axially extending sections on both axial sides of the larger diameter recessed part.

The invention allows the inserted screw to be removed again. This is necessary if the screws are inserted incorrectly or if for some other reason previously joined parts have to be separated from each other.

According to another feature of the screwdriver head according to the invention, the shaft is rotatable in one direction.

The sleeve has an inward facing collar at the end remote from the workpiece, the collar having at least one axial groove;
Advantageously, the shaft part is provided with a projection which extends from one area of the recessed part of smaller diameter to the end face of the sleeve supporting the helical spring and is movable through the axial groove.

〔Example〕

Embodiments of the power screwdriver head according to the present invention will be described with reference to the accompanying drawings.

In the drawing, reference numerals 1 and 2 designate shafts, which are clamped in a suitable manner in the chuck of a hand-held exciter drill, not shown, so that the rotational sequence of the drill shaft is transmitted to the shafts 1, 2. Preferably, an electric exciter is used as the power source and is switchable so that two rotation directions can be selected, so that Ml,2 can rotate clockwise or counterclockwise.

The shaft 1.2 has a circular seat part 3 at its end close to the workpiece.

The screwdriver piece 4 consists of a shaft portion 4a and an outer blade portion 4b. The shaft portion 4a has the shape of a polygonal prism, that is, a prism with a polygonal cross section. In the illustrated embodiment, the cross section is a regular hexagon, but the invention is not limited to this embodiment. The inner diameter of the outer seat 3 is in this case equal to the spacing of the opposing hexagonal shaft portions 4a of the screwdriver piece 4 in seconds.

The shaft portion 4a can be cross-bladed or chisel-shaped, depending on whether it is used for screwing in a cross-groove (Phillips-type) screw or a straight-groove screw.

Of course, it can also be in the form of a flute spanner. In the illustrated embodiment, the outer blade portion 4b is a cross-shaped blade.

Holes 5 extending in the radial direction are provided in the outer seat portion 3, and restraint balls 6 are movably housed in each of these holes.

The number of restraint regions 6 can correspond to the number of planes of the shaft portion 4a, but may also be less than the number of such planes.

The layer part 3 is surrounded by a sleeve 7 which is axially loaded by a spring 8.

By means of the spring-loaded sleeve 7, the restraining area 6 can be moved into a restraining position in which it engages with the plane of the screwdriver piece 4 or into a release position in which it is released.

The length of the sleeve 7 should match the screwing depth of the screw.
has in its upper part a recessed part with an inner diameter d, which part is divided into two axially extending sections 7' and 7". Between the two sections 7' and 7" there is a diameter There is a recessed part with a larger radius into which the restraining area 6 can enter in the released position.

One end of the spring 8 is supported by the end surface of the sleeve 7, and the other end is supported by the inner bottom of a cup-shaped member 9 surrounding the sleeve 7. This cup-shaped member 9 has one N along the axes 1 and 2.
A displacement in the IIa direction is provided, and for this purpose in the embodiment the stopper 10 fits into an annular groove in the part 2 of the shaft and rests on the outer bottom of the cup-shaped member 9. The cup-shaped member 9 prevents dust from entering the screwdriver head and damage caused by it.

There is a thrust receiver in the layer portion 3, on which the shaft portion 4a of the screwdriver piece 4 is supported at its end face.

In the drawing, this thrust receiver is formed by a ball 11, which reduces the friction occurring during screwing and removal to an acceptable level.

Since the screwdriver piece 4 is held within the M portion 3 by the annular spring 12, it will not fall off.

In order to prevent the restraint balls 6 from falling off when replacing the screwdriver piece 4, these restraint areas are held by stoppers (not shown). These stops may be formed by tapering the bore 5 at the end of the screwdriver piece 4 closer to the shank portion 4a, as shown.

The length of the sleeve 7 can be varied so that screws with different threading depths can be accommodated. Extension of the sleeve is not shown, but can be effected by removably connecting an extension piece to the sleeve 7 in a suitable manner. A screw connection has a good force t1.Other connection types can also be selected.

The sleeve 7, the restraining area 6 accommodated in the layer section 3, and the shaft section 4a of the screwdriver piece 4 together automatically transmit torque to the shaft section I when the predetermined screw-in depth of the screw is reached. It forms a joint that can be used to prevent What is important in this respect is that since the shaft part 4a is part of this joint, when the worn screwdriver piece 4 is replaced, the critical parts of the joint are also updated at the same time, which reduces the wear of the joint as a whole. It is. The remaining part of this joint is hardly exposed to thickening, so that by replacing the screwdriver piece 4, a substantially new joint is obtained.

As can be seen, at the proximal end of the sleeve 7 there is an inward collar 13, which collar is provided with at least one axial groove 14 in the recessed part of the smaller diameter d. From one section 7' it extends to the end face of the sleeve 7, which supports the coil spring 8. A projection 15 is provided on the shaft portion 2.

[Effect]

The functions of the brain power screwdriver head according to the present invention are as follows.

If a screw with a cross groove is to be screwed into a gypsum board,
The blade portion 4b of the screwdriver piece 4 is fitted into the cross groove of this screw. The drill is then actuated and the front end of the sleeve 7 is pressed against the plasterboard, so that the screw is driven into the plasterboard.

Due to the pressing force exerted on the drill, the sleeve 7 has a spring 8
is moved upwardly against the force, that is, into the cup-shaped member 9, and the restraining region 6 reaches the restraining position, so that the layer portion 3 and the shaft portion 4a of the screwdriver piece 4 are connected via the restraining region 6. A transmission connection is made between them.

When the screw reaches the desired screw-in depth, the extreme position of the sleeve 7! (The uppermost dead center position ra in the cup-shaped member 9) allows the restraint area 6 to move to the larger diameter D of the sleeve 7, so that the restraint ball 6 and the shaft portion 4a of the screwdriver piece 4 As a result of the breakage of the transmission connection, further tightening of the screw is not possible, even if the layer part 3 continues to rotate (
Figure 2).

When the drill is returned and the sleeve 7 is no longer in contact with the gypsum plate, the spring 8 forces the sleeve 7 into the illustrated restraining position, in which the locking ball 6 is connected in a transmission manner to the shaft portion 4a of the screwdriver piece 4. is repeated i'.

If, for whatever reason, it is necessary to remove the inserted screw, it is necessary to move the sleeve 7 axially upwards from the position shown in FIG. 2, ie in the direction of driving the screw. Restriction, the ball 6 is in the restraint position and engages the area 7'' of the smaller recessed part of diameter d.As the sleeve 7 moves upwards, the axial groove 14 protrudes unimpeded. Move through 15.

When this protrusion 15 comes to the lower annular surface of the collar 13,
When the sleeve 7 is rotated, the protrusion 81' appears as shown in FIG.
5 can hit this annular surface. The axial groove 14 and the projection 15 act as a bayonet joint. In the position shown in FIG. 3, the inserted screw can be removed by reversing the direction of the drill motor, ie by rotating it counterclockwise.

[Brief explanation of drawings]

1 is a partial sectional view of a screwdriver head according to the invention during screw insertion, FIG. 2 is a partial sectional view of the screwdriver head in the release position following the screwing process, and FIG. 3 is removed. It is a partial sectional view of the screwdriver head during the process. 1.2... Shaft, 3... Layer part, 4... Screwdriver piece, 5... Hole, 6... Directional bundle ball, 7... Sleeve, 1
, r”...Area, 8...Spring, D, d...Diameter Procedural amendment (method) July 15, 1988

Claims (1)

[Claims] 1. A shaft (1, 2) and a screwdriver piece (
4) and a coil spring supported on the shaft (1, 2) and preloading the sleeve (7) to enable it to move axially on the workpiece end of the shaft (1, 2). (8) and a restraining ball (6) provided between the screwdriver piece (4) and the sleeve (7), the depth of which allows the sleeve (7) to rest on the surface of the workpiece. radially, the shafts (1, 2) have at the end close to the workpiece a seat part (3) of circular cross-section, which seat part accommodates the restraining ball (6) in a transversely movable manner. A restraining ball (6) having a hole (5), in its restraining position, electrically connects the recessed part of the sleeve (7) with the smaller diameter (d) and the screwdriver piece (4); The sleeve (7) has a diameter (
In the release position where the restraint ball (6) enters the larger recessed part of diameter (D), the screwdriver piece (4) is released, and the smaller recessed part of diameter (d) characterized in that it is divided into two axially extending sections (7', 7'') on both axial sides of the larger recessed part,
Power screwdriver head. 2. Screwdriver head according to claim 1, characterized in that the shafts (1, 2) are rotatable in one direction. 3. The sleeve (7) has an inward collar (13) in the part remote from the workpiece, which collar (13) is provided with at least one axial groove (14), with the smaller diameter Extending from one area (7') of the recessed part to the end face of the sleeve (7) supporting the coil spring (8), an axial groove (
A projection (15) movable through the shaft (1, 2)
Screwdriver head according to claim 1, characterized in that it is provided in the part (2).