WO2004101227A1

WO2004101227A1 - Screwdriver with torque control

Info

Publication number: WO2004101227A1
Application number: PCT/EP2004/005283
Authority: WO
Inventors: Michael Abel
Original assignee: Wera Werk Hermann Werner Gmbh & Co Kg
Priority date: 2003-05-17
Filing date: 2004-05-17
Publication date: 2004-11-25
Also published as: ATE349299T1; DE502004002463D1; EP1631418A1; EP1631418B1

Abstract

The invention relates to a screwdriver comprising a handle (1) and a blade (2). The handle (1) comprises a front handle part (3) which is joined to the blade (2) and a rear handle part (4). The rear handle part (4) comprises a recess (9) which receives at least part of a torque control device which interacts with the blade (2) and the blade (2), which is essentially fixed to the handle (1) in the axial direction of the handle (1), protrudes through a through bore of the front handle part (3). The torque control limitation device forms a first tooth part (14) which is connected to the blade in an axially fixed or rotationally fixed manner and comprises a second tooth part (15) which is associated with the rotationally fixed, axially displaceable handle counter to the restoring force of a compression spring (16). The tooth parts (14, 15) form front toothings which surround the blade (2). The teeth form transversal flanks which are pressed against each other by the compression spring (16) and slide on top of each other when the limiting rotational torque is obtained. The invention also relates to a rotationally fixed and axially fixed bearing collar (18) associated with the blade (2), said bearing collar being mounted between bearing sections (19, 20) both parts of the handle (3).

Description

Screwdriver with torque limiter

The invention relates to a screwdriver having a handle and a blade, the handle having a front handle portion adjoining the blade and a rear handle portion facing away from the blade, the rear handle portion having a cavity for at least partially receiving a blade cooperating with the blade Torque limiting device and the handle to the axial direction of the handle substantially immovable blade penetrates a through hole of the front handle part, wherein the torque limiting device axially and rotationally connected to the blade first tooth part forms and a rotationally fixed and against the restoring force of a compression spring axially displaceable Handle associated second tooth part, wherein the tooth parts forming the blade end teeth, the teeth of which form inclined edges, which are pressed by the compression spring against each other and upon reaching a limit rotation momentes slide on each other.

A generic screwdriver is previously known from US 4,063,474. Within the cavity of the rear handle portion is a torque limiting arrangement. The triggering torque is adjustable there. A consisting of several handle parts screwdriver handle is also previously known from EP 0925 0 A2. US Pat. No. 5,764,298, US Pat. No. 2,396,040 and US Pat. No. 2,797,564 also disclose screwdrivers having a plurality of gripping parts, which are in particular screwed together and which form a cavity in which a torque limiting arrangement lies.

The invention has for its object to further develop the generic screwdriver nutzsvorteilhaft. The problem is solved by a rotatably and axially fixed to the blade associated bearing collar, which in particular is axially tied but rotatably mounted between bearing portions of the two handle parts. According to this embodiment, the pressure forces exerted on the tool by the user during the screwing operation are securely transferred to the handle. In a further development of the invention, it is provided that the bearing collar is formed by the blade-fixed tooth part. The bearing collar preferably rests on an area associated with the opening of the cavity. This allows the rear end of the blade to protrude freely into the cavity. The blade-proof tooth part and the counter-toothing of the grip-fixed tooth part form saw teeth which mesh with one another. In this way, in the screwing-in direction of a screw, the torque limitation can come into effect by the fact that, when a limit torque is reached, the tooth flanks slide off one another and slide over one another when a triggering torque is reached. The steep flanks, which run through the blade, in particular perpendicular to the plane of the plane, come into pressure contact in the release direction of the screw. As a result, a significantly higher torque can be applied in this direction of rotation. In a further development it is provided that the helical compression spring is supported on spacers. By selecting the thickness or the number of spacers, the limit torque can be adjusted. The end portion of the blade may penetrate a portion of the helical compression spring. In a preferred embodiment, the blade-proof tooth part is supported on an abutment surrounding the blade as a collar. The front handle part that forms this collar, a throat of the handle or even a cap for the opening of the handle cavity form. The counter-tooth part, which is axially displaceable within the handle against the restoring force of the compression spring, has on its outer circumferential wall in the direction of displacement extending ribs. These ribs protrude into rib gaps of corresponding ribs associated with the cavity wall of the cavity. The printing spring can not only rest on the bottom of the cavity. In a preferred embodiment of the invention it is provided that the compression spring is supported on the bearing collar. In this variant, the blade-proof tooth part can be located in the region of the free end of the blade. The entire torque limiting device is then firmly associated with the blade.

After loosening the front handle part, the blade can be taken out of the cavity together with the two tooth parts and the prestressed compression spring. This facilitates maintenance and assembly. Moreover, it is advantageous if the blade axially and rotationally fixed tooth part is supported on a washer, which is fixed by means of a screwed onto the free end of the blade nut. With this mother can then adjust the release torque. The counter-tooth part preferably forms a cavity. This cavity is formed as an annular cavity and can accommodate a portion of the compression spring. The compression spring then rests on the bottom of the ring cavity. The preferred shape of the handle is in addition to the elongated handle and the angle handle.

Furthermore, it can be provided that the two handle parts are locked together in the screwed state such that they are again unscrewed after destruction of one of the parting planes associated locking member. Unlike the prior art, in which the screw connection between the two handle parts can be solved at any time, for example, to change the release torque by replacing the spring or other components, this is no longer possible according to the invention. Since the disassembly of the two handle parts is connected to the destruction of a locking member, manipulations of the limit torque are immediately recognizable. Preferably, the locking member is formed so that the break is easily visible externally. In one embodiment of the invention, it is provided that each of the two grip parts forms a step in the region of the parting plane. This level forms in the screwed state an annular groove. There is a ring in this ring groove. The ring covers the dividing plane between the two handle parts. Each of the two stages forms at least one recess. In the screwed state, the recesses lie side by side in such a way that they complement each other to form a pocket. In this bag is in the screwed state, the locking member of the ring. This locking member forms a projection with two sections. One section is located in one of the two recesses, so that the recesses can not be rotated apart without the projection is destroyed. In a further development of the invention, it is provided that a portion of the projection rests firmly in one of the two recesses and the other portion forms a spring tongue, which can escape from its associated recess in Verschschraubrichtung and forms a turnstile in the other screwing. In this embodiment, the ring can be placed during assembly on the stage of a handle part, so that a portion rests firmly in the associated recess. When the two handle parts are screwed together, the step of the other handle part of the step carrying the ring approaches. The parting line is getting narrower, until the flank acts on the spring tongue. The spring tongue can then dive into the recess in which the projection already rests. If the end position is reached, in which both recesses form the said pocket, the spring tongue springs into the opposite recess. Preferably, the handle is made of plastic. The ring can also be made of plastic. It may be a plastic injection-molded part, which the locking member is integrally formed material.

Embodiments of the invention are explained below with reference to accompanying drawings. Show it: 1 shows a first embodiment of the screwdriver according to the invention in a perspective view;

Figure 2 shows the ring with two radially inwardly directed locking members.

3 shows a section along the line III - III in Fig. 4.

4 shows a section along the line IV - IV in Fig. 3.

Fig. 5 is an enlarged view of a detail of Fig. 3;

6 shows a section along the line VI - VI in Fig. 4.

Figure 7 is a section along the line VII - VII in Fig. 4.

8 shows a second embodiment of the screwdriver according to the invention with an angle handle in the view;

9 shows the screwdriver of the second exemplary embodiment with a quarter section in the region of the torque limiting device;

FIG. 10 shows the front view of the screwdriver according to FIG. 8; FIG.

Fig. 11 is a view of the blade with the torque limiting assembly installed;

Fig. 12 is a section along the line XII - XII in Fig. 10 and

13 is a section along the line XIII - XIII in Fig. 8. The screwdriver consists of a handle 1 and a blade 2. The handle 1 consists of two plastic parts 3,. It is a front handle part 3, the end face of the blade 2 springs, and a rear handle part 4, which forms a dome 5, which lies on the side facing away from the blade of the handle 1.

The blade 2 is rotatable relative to the handle 1 when a tripping torque is exceeded. The handle has in an inner cavity 9 but a locking mechanism which forms a torque limiting arrangement, with which by turning the handle 1 on the blade 2, a torque can be applied. When the release torque is reached, the blade turns in the handle. In the opposite direction significantly higher torques can be transmitted.

The front handle part 3 forms an internal thread 6. In this internal thread 6, an external thread 7 of a threaded flange of the rear handle 4 can be screwed. In this case, the front handle part 3 forms to form a parting plane 8 in touching contact with the rear handle part 4. In the region of the parting plane 8 forms each of the two handle parts 3, a stage 11 ', 11 "in the bolted together form the two stages 11 ', 11 "an annular groove 11 from. In the center of the bottom of the annular groove 11 extends the parting plane 8. In the annular groove 11 is a plastic ring 12. This plastic ring 12 has at two diametrically opposite points radially inwardly raving locking members 10. Each of the two locking members 10 forms a first projection 10th The first projection 10 'lies in a recess 13' of the front grip part 3. The second portion 10 "lies in a recess 13" of the rear grip part 4. The two projections savings 13 'and 13 "form a bag 13 when screwed together.

As shown in FIG. 7, the second portion 10 ", which rests in the recess 13", designed as a spring tongue. According to this embodiment, according to the representation of FIG. 7, the rear grip part 4 can shift there to the left relative to the front grip part 3. If the spring tongue 10 "acted upon by the boundary of the recess 13", it can dip into the other recess 13 '. A displacement of the rear handle part 4 relative to the front handle part 3 in the opposite direction, ie to the right, is not possible because the spring tongue 10 "is blocking the corresponding wall of the recess 13".

7, the rear grip part 4 is nevertheless displaced to the right (in the screwing-on direction) in relation to the front grip part 3, so that the spring tongue 10 "or the entire catch element 10 breaks off from the ring recognizable by the screwdriver handle.

When mounting the handle, first the ring, which is shown in Fig. 2, placed on the step 11 "of the front handle part 3. In this case, the portion 10 'of the locking member 10 projects into the recess 13' 7 are screwed into the internal thread 6. As a result, the distance between the two handle parts 3, 4 in the region of the parting plane 8 decreases until the spring tongue 10 "is acted upon. Join the two recesses 13 ', 13 "in opposition to the formation of the pocket 13, the spring tongue 10" can spring into its associated recess 13 ". The rear end of the blade 2, which consists of steel, is surrounded by a plastic part. This plastic part forms a toothed part 14. The tooth part 14 has a toothing 14 'with sawtooth-shaped teeth. The tooth part 14 is rotatably connected to the blade 2.

The cavity 9 of the rear handle portion 4 has not shown, extending in the axial direction grooves or ribs. In the grooves of the wall of the cavity 9 engage ribs of a counter-tooth part 15, not shown. The counter-tooth part 15 has a toothing 15 'which corresponds to the toothing 14'. On the rear end face of the counter-tooth part 15 are spacers 17. On the spacers 17, a helical compression spring 16 is supported, which is supported with its other end on the bottom of the cavity 9. An end portion of the plastic-coated blade protrudes into the cavity of the helical compression spring 16 a. This end portion of the blade 2 extends through the sleeve-shaped counter-tooth part 15th

The rear handle part 4 forms a bearing wall 19, against which an annular collar 18 of the tooth part 14 is supported. With a bearing projection 20, the tooth part 14 is supported on an abutment 21 of the front grip part 3, so that it rests axially fixed in the handle 1. The tooth part 14 receives the blade 2. The blade 2 is stuck with its end in the up to the hollow of the compression spring 16 extending plastic part 14th

By selecting suitable spacers 17, the triggering torque can be adjusted. The blade 2 penetrates with game an axial cavity of the front handle part. 3

Essential in the embodiment described above, the axial bearing of the torque limiting device in the region of the handle. The Storage takes place with a rotatably and axially fixed to the blade associated bearing disc. The one end 20 of the bearing plate 18 is supported on an abutment 21 of the front handle part 3 and the other end of the bearing plate 18 is supported on a portion of the rear handle portion 4 from. If the two gripping parts 3, 4 are separated from one another, then the blade together with the torque limiting arrangement can be removed from the cavity 9.

In the second embodiment shown in Figures 8 to 12, the entire torque limiting arrangement is fixedly associated with the blade. The blade 2 consists of a hexagonal steel with a gradation 30. On this gradation 30, a circular metal disc 18 is supported. This metal disc 18 forms a bearing disc. The tapered portion of the blade 2 in itself is supported on the rear broad side surface of the bearing plate 18 is a strong helical compression spring with a rectangular winding profile from. The clamping force of this helical compression spring 16 defines the limit torque at which the teeth 28 to be explained below a toothing 15 and a counter toothing 15 are disengaged.

The end facing away from the bearing plate 18 end of the helical compression spring 16 is inserted into an annular cavity 29 which is associated with a counter-tooth part 15. The counter-tooth part 15 is made of plastic and has ribs 23 on its outer wall.

The counter tooth part 15 forms saw teeth 27. These saw teeth 27 are located on the bottom of the annular groove on which the compression spring 16 is supported, opposite side. The teeth 28 engage in gaps of saw teeth 27 of a toothed part 14. The tooth part is also made of plastic. But it is rotatably and axially fixed to the blade 2 assigned. The force of the prestressed compression spring 16 presses the toothed part 14 against a threaded portion 24 the washer 2 associated washer 26. The washer 26 is held by a nut 25 which is screwed onto the threaded portion 24.

With the nut 25, the clamping force of the compression spring 16 and thus the release torque can be adjusted.

The above-mentioned ribs 23 of the counter-tooth part 15 engage in grooves lying between ribs 22, wherein the ribs 22 are formed by the wall of the cavity 9. As a result, the mating tooth portion 15 can be in

Move axial direction against the clamping force of the compression spring 16 within the cavity 9, but it is rotatably associated with the rear handle part 4. Thus, a torque can be transmitted from the grip part to the blade via the teeth 27, 28.

The front handle part 3 forms a closure cap. This cap is clipped into a diameter-extended portion of the cavity 9. An inner collar of the front grip part 3 forms an abutment 21, on which the bearing plate 18 can be supported.

The operation of this screwing tool is the following: For mounting, first the bearing plate 18 is pushed over the reduced diameter portion of the blade 2. Then, the compression spring 16 and the counter tooth part 15 are mounted. On the counter-tooth part 15, the tooth part is then pushed, which forms a collar 30 which projects into a bottom-side guide opening of the counter-tooth part 15. With the interposition of the washer 26 is then tensioned by screwing the nut 25 on the threaded portion 24, the compression spring. The preassembled in the figure 11 part is then inserted into the opening 9 of the rear handle part 4, where it rests force-free. The outer edge of the bearing plate 18 is supported on the end faces of the ribs 22. These form the bearing wall 19. The Drehnionientbegrenzungseinrichtung velvet blade 2 is held by means of the cap 3 within the cavity, the edge of the collar forms the abutment 21 which rests against the forward facing broad side of the bearing plate 18.

If a torque is applied to the blade 2 via the handle, shear forces which result in the teeth 27, 28 becoming disengaged when a limit torque is exceeded are produced on the inclined flanks of the teeth 27, 28. The compression spring 16 is slightly tensioned.

All disclosed features are essential to the invention. The disclosure content of the associated / attached priority documents (copy of the prior application) is hereby also incorporated in full in the disclosure of the application, also for the purpose of including features of these documents in claims of the present application.

Claims

EXPECTATIONS

1. Screwdriver with a handle (1) and a blade (2), the handle (1) having a front handle part (3) adjoining the blade (2) and a rear handle part (4), the rear handle part (4) one

Has cavity (9) for at least partially receiving a rotary torque limiting device cooperating with the blade (2) and the blade (2), which is essentially immobile in relation to the handle (1) in the axial direction of the handle (1), projects through a through hole in the front handle part (3), wherein the rotary mandrel limiting device forms a first tooth part (14) which is axially and non-rotatably connected to the blade and has a second tooth part (15) which is non-rotatably and axially displaceable against the restoring force of a compression spring (16), the tooth parts (15) 14, 15) form the serrations surrounding the blade (2), the teeth of which form inclined flanks, which are caused by the compression spring

(16) are pressed against each other and slide on each other when a limit torque is reached, characterized by a rotationally and axially fixed to the blade (2) associated bearing collar (18) which is mounted between bearing sections (19, 20) of the two handle parts (3).

2. Screwdriver according to claim 1 or in particular according thereto, characterized in that the toothing (14 ') of the blade-fixed tooth part (14) and the counter toothing (15') of the handle-fixed tooth part (15) form interlocking saw teeth.

Screwdriver according to one or more of the preceding claims or in particular according thereto, characterized in that the limit torque is defined by spacers (17) against which the helical compression spring (16) is supported.

4. Screwdriver according to one or more of the preceding claims or in particular according thereto, characterized by an end section of the blade (2) penetrating the counter-tooth part (15) and part of the helical compression spring 16.

5. Screwdriver according to one or more of the preceding claims or in particular according thereto, characterized in that the bearing collar (18) is formed by the blade-fixed tooth part (14).

6. Screwdriver according to one or more of the preceding claims or in particular according thereto, characterized in that the blade-fixed tooth part (14) is supported on a counter bearing (21) which surrounds the blade as a collar.

7. Screwdriver according to one or more of the preceding claims or in particular according thereto, characterized by axial ribs (23) of the counter-tooth part (15) surrounding the blade in an annular manner, which cooperate with corresponding ribs (22) of the cavity wall of the cavity (9).

8. Screwdriver according to one or more of the preceding claims or in particular according thereto, characterized in that the compression spring (16) on the bottom of the cavity

(9) supports.

Screwdriver according to one or more of the preceding claims or in particular according thereto, characterized in that the bearing collar (18) is made of a disk, in particular made of metal is trained.

10. Screwdriver according to one or more of the preceding claims or in particular according thereto, characterized in that the compression spring (16) is supported on the bearing collar (18).

11. Screwdriver according to one or more of the preceding claims or in particular according thereto, characterized in that the compression spring (16) supported on the bearing collar (18) together with an opposing tooth part (15) supported by the compression spring (16) and the

Tooth part (14) forms a torque limiting device permanently assigned to the blade.

12. Screwdriver according to one or more of the preceding claims, or in particular according thereto, characterized in that the rotary norma limiting device permanently assigned to the blade (2) is screwed by a nut (25) screwed onto a thread (24) formed by the end of the blade (2) ) is fixed, by means of which nut (25) the triggering torque is preferably also adjustable.

13. Screwdriver according to one or more of the preceding claims or in particular according thereto, characterized in that the counter-tooth part (15) carrying the counter-toothing (15 ') forms an annular cavity into which a partial area of the compression spring (16) protrudes which is on the floor the ring cavity (9) supports.

14. Screwdriver according to one or more of the preceding claims or in particular according thereto, characterized in that the handle is an angle handle.

15. Screwdriver according to one or more of the preceding claims or in particular according thereto, characterized in that the front handle part (3) is a closure cap which forms a counter-bearing collar (21).

16. Screwdriver according to one or more of the preceding claims or in particular according thereto, characterized in that the edge of the disk forming the bearing collar (18) rests on the ends of the cavities associated with the cavity wall of the cavity (9).