GB2258771A

GB2258771A - Electrical track coupling system with a position sensor.

Info

Publication number: GB2258771A
Application number: GB9217352A
Authority: GB
Inventors: Rudolf Moeller; Peter Mueller; Helmut Goettling; Gerhard Scharnowski
Original assignee: Mannesmann AG
Current assignee: Vodafone GmbH
Priority date: 1991-08-14
Filing date: 1992-08-14
Publication date: 1993-02-17
Also published as: IT1255405B; GB9217352D0; DE4127205A1; ITMI921631A1; FR2680438A1; DE4127205C2; ITMI921631A0

Description

2_ -7-71 ) Of 1 Linear drives and drive housing assemblies therefor is

This invention relates to linear drives, and particularly to drive housing assemblies therefor.

From a brochure of the company Mecman, "Scanning Unit for 170 Series" it is known to use magnetic field sensors for linear drives with a mouldedon cable. From another brochure, "Magnetic piston system Type M/457XX11 of the company Martonair the use of magnetic field sensors for linear drives with plug contacts is known. Magnetic field sensors which are connected to the connecting cables by means of solder bridges are also known for linear drives.

It will be understood that a moulded-on cable hampers changing the position of the magnetic field sensor just as much as a plug contact, both configurations being unwieldy and necessitating considerable contacting costs. The present invention addresses the problem of simplifying the attachment and contacting of the sensor and in so doing to set the electrical connection of the sensor to its various positions.

The present invention is directed at a drive housing assembly for a linear drive in which a slide unit with a position sensor is borne on the assembly. The assembly comprises a housing formed with a longitudinal groove; an elongate body supported on a section mounted in the groove; a conductive track located in the elongate body; and a contact plate with a line sensor detachably fitted to the body in juxtaposition with the track, the plate having at least one element for contacting the conductive track, the or each element being adjustable to make such contact. Normally, the mounted section of the elongate body is 2 hinged and adjustable for mounting in the groove of the housing.

Primary advantages of the invention are that no cables need be laid, that more rapid assembly is possible than previously; and that more rapid replacement and repositioning of the sensor can be achieved. Further, the entire linear unit is easier to manipulate.

In one preferred embodiment of the invention the elongate body comprises a base and a hinged cover, with a plurality of conductive tracks embedded in the base which itself has a longitudinal recess for receiving a shaped arm of the contact plate. The contact plate can be secured on the body by means of a screw through the shaped arm.

The hinged cover can be connected to the housing by means of a snap-in connection, consisting of an approximately pincer-shaped entrance and one or more hooks moulded on to the hinged cover. This can considerably enhance the protection of the sensor, of the conductive tracks and also of the contact means in the contact plate.

The manufacture of assemblies according to the invention can be particularly economic when the elongate body is made of plastics material in an extrusion process and has a projection matched to the longitudinal groove of the drive housing. On the base of the projection it is preferred that a central first hinge is formed, which facilitates mounting of the body in the assembly.

In another preferred feature of the invention the or each contact element is a screw which cooperates with a matching thread in a contact bridge in the contact plate for urging into engagement with the conductive track. This achieves a flat construction and 3 beneficial accessibility, even when a hinged cover is used, and has been swung down.

The conductive track used can be embedded in insulating strips. When a grooved profile is used, this can also provide a means of attachment for the conductive track.

According to a further preferred feature of the invention a plurality of lengths of conductive track are disposed along the length of the housing, on each of which lengths at least one contact plate with a line sensor is fitted. This means that a plurality of sensors can be brought into a given position and switched independently of one another.

Finally, another reduction in production costs can be achieved by setting the distance between the conductors of the conductive track on an insulating strip to correspond to the distance between conductors on commercially-available ribbon cables. In this way the simple contacting of these two conductors by means of a commercially-available cut-and- clamp connection is rendered possible.

The invention will now be described by way of example and with reference to the accompanying schematic drawings wherein:

Figure 1 shows a front view of a drive housing assembly according to the invention; Figure 2 is a sectional view through the assembly of Figure 1; Figures 3 to-6 illustrate successive stages in the creation of an assembly according to the invention; and Figure 7 shows a perspective view of the housing assembly with separate conductive tracks installed.

4 Longitudinal grooves 3 are formed on an outer surface 2 of a linear drive with a drive housing 1 (Figures 3 - 6). These longitudinal grooves 3 serve for the attachment of a sensor 4 of adjustable length, to which electric conductors 5 are connected. The sensor 4 cooperates with a permanent magnet embedded in the drive housing 1 or in the interior of the cylinder in a piston. A magnet holder 1b is shown (Figure 6) as protection for the permanent magnet and an arrangement on the slide la of the drive housing 1. However, the permanent magnet may equally well be located in the interior of the cylinder, i.e. in the piston.

A hinged housing 6 is attached to the drive housing 1 in the longitudinal groove 3. This housing 6 contains a multi-wire continuous conductive track 7 with which a detachable contact plate 8 for the sensor 4 is associated within the housing 6. In the position of the contact plate 8 for the sensor 4 as shown in Figures 1 and 2, there are provided contact elements 9, with the middle contact element 9 being held out of the contact position in Figure 2 and the upper and lower elements being brought into the contact position.

A plurality of the conductors of the conductive tracks 7 is provided in the housing 6, and they extend, adjacent to one another, in the longitudinal direction of the drive housing 1. Furthermore, there is a longitudinal recess 12 which also runs in the longitudinal direction of the drive housing 1, into which recess a profiled arm 13 which forms part of the contact plate 8 engages.

The housing 6 is preferably made of plastics material (polyamide with fillers, such as glass fibres and the like), and is produced in an extrusion process, with all the profile contours being moulded at the same time. To this effect. the housing 6 has a projection is 14, on the base 15 of which a central, first hinge 16 is provided. Furthermore, in the further course of the housing cross-section a hinged cover 17 is articulated with a second hinge 19.

Advantageously, the conductive tracks 7 are likewise included in the manufacture of the housing 6.

After prior insertion of the projection 14 into the longitudinal groove 3 of the drive housing 1, at the same time the contact plate 8 is attached by means of an adjusting screw 20 which extends through the profiled arm 13, which will be explained in greater detail below.

The hinged cover 17 of the housing 6 furthermore has a snap-in connection 21 which is formed of an approximately pincershaped entrance 22 and one or more hooks 23 moulded on to the hinged cover 17.

In the contact plate 8, which is made of insulating material (Figure 2), screws 10b provided with tips 10a 9 are screwed as contact elements into a contact bridge 25 provided with electrically conductive threaded holes 24, with (Figure 1) one zero conductor and one current-carrying conductor in each case being connectable to the sensor 4.

The conductive tracks 7 are embedded in insulating strips 26. The insulating strip 26 itself is located in a recess 26a, said recess having a dovetaillike profile, as shown.

A continuous or severed (Figure 7) insulating strip 26 provided with a conductive track 7 may be embedded in the housing 6 within the length of the drive housing 1. Then at least one contact plate 8 is associated with each section of the conductive track over the insulating strip 26. The advantage thereof consists in doubling the number of sensors which are used.

7 6 A distance 27 between the individual conductors of the conductive track 7 on the insulating strip 26 corresponds to the distance between conductors on commercially available ribbon cables.

Figures 3 to 6 show the method of operation and the rapid assembly of the housing 6. In Figure 3, the housing 6 is pivoted into the longitudinal groove 3, folded up at the first hinge 16, then the housing 6 is placed against the outer surface 2 of the drive housing in the direction of arrow 28, so that the housing position of Figure 4 is reached. Then the contact plate 8 with its profiled arm 13 is forced into the longitudinal recess 12 hooked into a contact plate undercut 8a with a housing projection 6a and pivoted across the insulating strip 26 in the direction of arrow 29. This then yields the position of Figure 5, in which the contact plate 8 with the sensor 4 is set to the correct length position and the individual contacts marked 1 to 5 in Figure 1 are pressed on to the respective conductors of the conductive track 7. The setting of the contact plate 8 takes place simultaneously with the tightening of the adjusting screw 20 (Figure 5), so that the housing 6 is now attached to the drive housing 1, the contact plate 8 is set to its position of the sensor 4 in one of the directions 30 or 31, and then only the hinged cover has to be hooked in the direction of arrow 32 in accordance with Figure 6.

1 -1 claims 1. A drive housing assembly for a linear drive in which a slide unit with a position sensor is borne on the assembly, which assembly comprises a housing formed with a longitudinal groove; an elongate body supported on a section mounted in the groove; a conductive track located in the elongate body; and a contact plate with a line sensor detachably fitted to the body in juxtaposition with the track, the plate having at least one element for contacting the conductive track, the or each element being adjustable to make such contact.

is

Claims

2. An assembly according to Claim 1 wherein the mounted section of the

elongate body is hinged and adjustable for mounting in the groove of the housing.

3. An assembly according to Claim 2 wherein the elongate body is a plastics extrusion with an integral cover section pivotally attached by means of an additional longitudinal hinge.

4. An assembly according to Claim 3 wherein the cover section can be latched to the elongate body by means of a snap connection.

5. An assembly according to any preceding claim wherein the elongate body comprises a base formed with a longitudinal recess, and wherein the contact plate has a shaped arm, the distal end of which is received in the recess to locate the contact plate relative to the conductive track.

6. An assembly according to claim 5 wherein the contact plate is secured on the body by means of a screw through the shaped arm.

7. An assembly according to Claim 6 wherein the screw extends into the mounted section of the elongate body.

1 8. An assembly according to any preceding claim wherein the or each contact element is a screw which cooperates with a matching thread in a contact bridge in the contact plate for urging into engagement with the conductive track.

9. An assembly according to any preceding Claim wherein the conductive track is of multi-wire construction.

10. An assembly according to Claim 9 wherein the construction comprises wires embedded in insulating strips.

11. An assembly according to Claim 9 or Claim 10 wherein the spacing between the wires of the conductive track corresponds to the distance between conductors on commercially-available ribbon cables.

12. An assembly according to any preceding Claim wherein a plurality of lengths of conductive track are disposed along the length of the housing, on each of which lengths at least one contact plate with a line sensor is fitted.

13. A drive housing assembly for a linear drive, substantially as described herein with reference to the accompanying drawings.

14. A linear drive with a drive housing on which longitudinal grooves for attaching an adjustable-length sensor are provided on an outer surface, to which housing electric conductors are connected and on the piston or slide of which a position sensor is located, wherein a single-wire or multi-wire continuous conductive track is located in a hinged housing which can be adjusted and attached in the longitudinal groove of the drive housing, and wherein a detachable contact plate of the sensor is removably attached within the housing facing said conductive track, in which plate one contact element is provided associated with the respective conductive track, the element being adjustable into contact with the insulated conductive track.

15. A linear drive comprising a housing assembly according to any preceding Claim.

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