Adjustable axial fastening device for an actuating cable

Abstract: The invention relates to an adjustable axial fastening device for an actuating cable (1), which comprises an actuating covering (2) and a core (3), at least one of these two actuating members being provided at the end with an adjustable axial fastening device (4). In order to provide an adjustable axial fastening device, which can be precisely adjusted and is easy to assemble, it is proposed according to the invention to use a securing member (8) for an adjustable axial fastening device (4), the said securing member (8) being movable radially with respect to the actuating cable (1) and being provided on the inside with a radial set of teeth (22) in an area which embraces the attachment part.

Description: The invention relates to an adjustable axial fastening device for an actuating cable, which comprises an actuating covering and a core, at least one of these two actuating members being provided at the end with an adjustable axial fastening device. With actuating cables it is necessary to adjust them during assembly and possibly to carry out a further (subsequent) adjustment at a later time. In this case it is usual to set the axial distance between the actuating covering and the core. For this purpose an adjustable axial fastening device is provided at the end of at least one of these two components. Generally known adjustable axial fastening devices comprise a threaded part for example, on which a stop is formed by means of two nuts locked against each other. It is likewise generally known to screw a threaded part of this type firmly in a holding means and to secure it by a lock nut. In addition it is generally known, for throttle cables for internal-combustion engines for example, to provide a fastening device with a plurality of grooves arranged in succession and to insert a retaining spring into one of these grooves, the retaining spring then acting as a stop on a retaining plate. A bowden cable adjusting device rotatably mounted on the cable conduit is shown in EP 0 509 629 A1. The adjusting device comprises two actuating members, namely an actuating covering and a core, of which at least one actuating member is provided at one end with an adjustable axial fastening device. An opening for receiving the fastening device is provided on a holding means. The actuating member present on the fastening device is movable axially in the fastening device, and a securing member effective between the actuating member and the fastening device is used to fix the axial position of the actuating member. Therfore the securing member is movable radially in the fastening device and is locked in a securing position, the securing member has an area embracing the actuating member, and the said area has a radial set of teeth. In contrast, the object of the invention is to provide an adjustable axial fastening device for an actuating cable, which can be precisely adjusted and is easy to assemble. In order to attain this object, it is proposed according to the invention to use a securing member for an adjustable axial fastening device, the said securing member being movable radially with respect to the actuating cable and being provided on the inside with a radial set of teeth in an area which embraces the attachment part. It is proposed to make the area in the attachment part cooperating with the securing member softer than the securing member in the area of its set of teeth and to make it at least partially plastically deformable. With this the set of teeth of the securing member bites into the soft area of the attachment part during assembly and produces a corresponding toothing here. A rapid and precisely adjustable axial fixing is now possible in an advantageous manner. As an advantageous further embodiment of the invention it is proposed to give the set of teeth of the securing member a pitch. This makes it possible to alter the axial adjustment subsequently, without the securing member having to be released. Although it is now necessary to rotate the attachment part for this subsequent adjustment, the initial assembly without rotation is retained. The invention is described in greater detail below with reference to the embodiment illustrated in the Figures, in which Fig. 1 is a longitudinal section through an axial fastening device with an actuating cable, and Fig. 2 is a section along the line II-II in Fig. 1. The actuating cable 1 illustrated comprises an actuating covering 2 and a core 3. At the end of the actuating cable 1 an attachment member 4 is mounted on the actuating covering 2 thereof, and is held in a holding means 5 and acts as an adjustable axial fastening device. The core 3 extends beyond the attachment member 4 and is protected from soiling and damage by a sleeve 6 mounted in the attachment member 4. A further, non-adjustable fastening device (not shown) is provided at the end of the core 3. The attachment member 4 comprises an outer sleeve 7, a securing member 8 and an inner sleeve 9. The outer sleeve 7 is fastened to the holding means 5 in both the axial and the radial directions. In the present embodiment a continuous groove 10, into which the holding means 5 engages, is provided for this purpose on the outer sleeve 7. The inner sleeve 9 is mounted on the actuating covering 2 of the actuating cable 1 and is securely connected thereto; when an inner sleeve 9 is produced from plastics material, this can be carried out for example by injection-moulding onto the actuating covering 2. The outer sleeve 7 is provided with a bore 11 which receives the inner sleeve 9. The inner sleeve 9 is guided in the said bore 11 by O-rings 12 which are inserted into grooves 13 in the outer sleeve 7. As shown in greater detail in Fig. 2, the securing member 8 is guided in a substantially box-shaped aperture 14 in the outer sleeve 7. On its walls situated radially to the actuating cable 1 the aperture 14 has two spaced steps 15, 16. Corresponding thereto, two catching fingers 17, 18 likewise provided with two steps 19, 20 are arranged on the securing member 8. In the end position of the securing member 8 illustrated in Fig. 2, the actuating cable 1 is fixed with respect to its axial position, by the securing member 8 embracing the inner sleeve 9 and thus securing it axially with respect to the outer sleeve 7. In this case, the first steps 19 of the catching fingers 17, 18 engage behind the corresponding first steps 15 of the aperture 14, and the second steps 20 of the catching fingers 17, 18 engage behind the second steps 16 of the aperture 14. In an assembly position (not shown) the second steps 20 of the catching fingers 17, 18 engage behind the first steps 15 of the aperture 14, so that, although the securing member 8 is held in the aperture 14, it does not yet engage with the inner sleeve 9. As is clear from Fig. 2, in its end position illustrated, the securing member 8 terminates flush with the outer contour of the outer sleeve 7, so that there are no engagement surfaces for inadvertently detaching the securing member 8 from its locked state. If the securing member 8 is to be removed or detached, it is necessary to grip and press together the catching fingers 17, 18 by reaching into the aperture 14, so that the steps 19, 20 of the catching fingers 17, 18 are disengaged from the steps 15, 16 of the aperture 14. The inside of the securing member 8 has a first area 21 which embraces a corresponding second area 23 of the inner sleeve 9. In this case the internal dimension of the first area 21 is slightly smaller than the external dimension of the second area 23, so that where the two areas 21, 23 touch there is penetration of the two areas 21, 23. For this purpose, in the embodiment, the first area 21 of the securing member 8 is provided with a set of teeth 22 and the corresponding area 23 of the inner sleeve 9 is provided with a set of teeth 24. In the end position illustrated, the sets of teeth 22, 24 mesh and thus produce positive locking in the axial direction between the inner sleeve 9 and the securing member 8. The securing member 8 is in turn supported in the aperture 14 on the outer sleeve 7, and the said outer sleeve 7 is then supported by the groove 10 on the holding means 5, so that as a whole the actuating covering 2 is fixed axially on the holding means 5. In the example illustrated it is possible to select the axial position of the actuating covering 2 in a stepped manner in stages, corresponding to the width of the sets of teeth 22, 24. In addition, the sets of teeth 22, 24 are given a pitch, so that by rotating the inner sleeve 9 with respect to the securing member 8 a continuous axial displacement can be achieved. In order to make possible an axial setting of this type for a subsequent or fine adjustment, a gripping area 25 is provided on the inner sleeve 9, the said gripping area 25 having radial gripping members, so that the inner sleeve 9 can be gripped for rotation purposes. In the case of a fixed connexion between the inner sleeve 9 and the actuating covering 2, the said actuating covering 2 must be jointly rotated, whereas in the case of an alternative provision of a rotatable mounting of the actuating covering 2 in the inner sleeve 9 the actuating covering 2 need not be rotated for fine adjustment. In one embodiment (not shown), the inner sleeve 9 is made completely softer, or softer at least in the region of the aforesaid set of teeth 24, than the securing member 8 in the region of its set of teeth 22. A set of teeth 24, however, can no longer be provided, but instead this area is now made smooth. When the securing member 8 is assembled, the set of teeth 22 thereof bites into the softer material of the inner sleeve 9 and produces a corresponding toothing by plastic or at least partially plastic deformation of the material. As a result of this deformation the forces during assembly are greater, but a continuous adjustment of the axial position of the actuating cable 1 is now possible during the initial assembly. The possibility described above for subsequent adjustment is retained, since as the inner sleeve 9 is rotated the set of teeth 22 bites further into the material and thus gradually produces a thread. It is to be understood that the reverse case of application is also possible, i.e. the inner sleeve 9 has a set of teeth 24 on the outside, whereas the area of the set of teeth 22 on the securing member 8 is now made softer and is provided with a smooth surface. It is also to be understood that the axially adjustable attachment member 4 illustrated can be used in the same way for the actuating covering 2 as for the core 3.

Claims: An adjustable axial fastening device for an actuating cable (1), comprising two actuating members, namely an actuating covering (2) and a core (3), of which at least one actuating member is provided at one end with an adjustable axial fastening device (4), wherein an opening for receiving the fastening device (4) is provided on a holding means (5), the actuating member (2, 3) present on the fastening device (4) is movable axially in the fastening device (4), and a securing member (8) effective between the actuating member (2, 3) and the fastening device (4) is used to fix the axial position of the actuating member (2, 3), wherein the securing member (8) is movable radially in the fastening device (4) and is locked in a securing position, the securing member (8) has an area (21) embracing the actuating member (2, 3), and the said area (21) has a radial set of teeth (22), characterized in that an area (23) of the actuating member (2, 3), present inside the fastening device (4), is softer than the securing member (8) in the area (21) of its set of teeth (22) and is at least partially plastically deformable. A fastening device according to Claim 1, characterized in that the set of teeth (22) of the securing member (8) is given a pitch.

Inventors: BRAVO ERNESTO, BRAVO, ERNESTO
Applicants: PORSCHE AG, DR.ING.H.C. F. PORSCHE AKTIENGESELLSCHAFT
Application year: 1997
Main classification: F16C1
IPC codes: F16C1