GB2149115A

GB2149115A - Follow-up mechanism

Info

Publication number: GB2149115A
Application number: GB08426981A
Authority: GB
Inventors: Norbert Helmschrott; Herbert Kirner
Original assignee: Kienzle Apparate GmbH
Current assignee: Digital Kienzle Computersysteme GmbH and Co KG
Priority date: 1983-10-27
Filing date: 1984-10-25
Publication date: 1985-06-05
Also published as: DE3338972C2; GB2149115B; DE3338972A1; FR2554226A1; FR2554226B1; JPH053884B2; JPS60173413A; GB8426981D0

Abstract

A follow-up mechanism (e.g. for recording measuring devices) comprises an angular position transducer 30, 31 (32 Fig. 3), a motor 12 and a shaft 8 mounted parallel to the motor shaft 7 and driven by reduction gears 17, 18, 19, 20, 21 mounted on one side of a support 1. The end of the shaft 8 carrying coupling means 9 lies on the opposite side of the support 1 from the reduction gearing so that the motor, angular position, transducer and reduction gearing occupy a space (0 Fig. 1) the height of which is given by the length of the shaft 8, which is long so as to reduce wear and ease the required mounting tolerances. <IMAGE>

Description

SPECIFICATION Follow-up mechanism for a compensation measuring device The Invention relates to a follow-up mechanism for a compensation measuring device having a setting motor, an angle generator, a reduction gearing and a setting shaft which by means of a suitable coupling means is in operative connection with the recording and/or indicating means in the measuring device and which is arranged in a support carrying the functional elements of the follow-up mechanism parallel at least to the shaft of the setting motor.

It is known when using the compensation measuring method which is preferably applied in recording measuring devices--as an example a tachograph shall be named-that the target value delivered by a generator is continuously compared with the indicated actual value and that in the case that the actual value and the target value are unequal the compensating value is changed respectively followed up until at the output of the amplifier of the compensation measuring circuit there is no current flow.For the follow-up process normally a direct current controlled setting motor is used which by means of a suitable gearing simultaneously sets up the acutal value at the recording and indicating means and on the other hand actuates a potentiometer the output voltage of which is proportional to the actual value and is returned to the comparison means of the measuring circuit. The gearing driven by the setting motor in this case has the task to adapt the number of revolutions of the setting motor to the range of motion of the indicating and recording means by a suitable reduction adapted to the individual measured value whereby the gearing also operates as a torque transformer reducing the load on the setting motor result ing from the recording forces.It was already known to mount the parts of such a follow-up mechanism in a support to be inserted into the measuring device so that the follow-up mechanism represents a unit independent of the measuring device and to be separately handled and tested. Nevertheless the space required for and the cost of mounting of the known follow-up mechanism was in decided contrast to the cost of the compensation mea suring circuitry serving to treat the measured values.Due to this situation and due to a general demand for a multifunctional use and enhancement of the capability-of exchanging constructional and functional units, for machine mounting as well as for the reduction in the depth of the measuring device and thereby also the contraction of the individual functional units there has been a demand to create a follow-up mechanism with an architecture having as little parts as possible using as little space as possible and also being very ecconomically mountable.

To solve this problem it is provided that between the setting motor and the setting shaft there is a reduction gearing in the form of a spur gear and is arranged in an essentially flat space at one side of the support, that the setting shaft is mounted in the support so that the end of the setting shaft bearing the coupling means is arranged at the other side of the support and that the setting motor and the angle generator are so arranged on the support that its contours are essentially within a space the hight of which is defined by two parallel planes the distance of which corresponds to the length of the setting shaft and that a lid is attributed to the support at the gearing side for closing the device.

A preferred embodiment is also characterized in that the ring-shaped resistor lanes which are coaxial to the setting shaft are connected to the support and in that the wiper connected to a toothed wheel of the reduction gearing is connected to the setting shaft and attributed to the resistor lanes.

Further advantageous features of the invention are described in the subclaims.

The solution found is based on the idea that the setting shaft together with the coupling means mounted thereon will be that constructional part within the follow-up mechanism which when miniaturisation and building space contraction are consequently followed up will have the biggest length. This is due to the fact that at the setting shaft remarkable torques are effective. Because of the desired exactness of transfer a rather long mounting support should be achieved to reduce the wear and the tolerances so that there are no unusually tight tolerances in the mounting process. That means that the length of the setting shaft defines the depth of the space within which it seems advisable to arrange all the remaining constructional parts of the follow-up mechanism.

Apart from the fact that the problem which has been set has been solved in every aspect the solution found is an easily mountable flat building unit which can serve multi purposes and which since it is closed against dust can be made commercially available as an independent follow-up mechanism not only to be used in a specific measuring and recording device.

The object has specifically been achieved-wherever that was possible--in that the individual building parts have been made to serve multiple purposes. The heretofore usual architecture in several stages as well as the individual fastening of the parts by separate fastening and securing means has been given up. But it has also been recognized that the very exact positioning of the setting shaft can be used for integrating the angle generator into the follow-up mechanism.

In the following the invention shall now be explained in detail with reference to the enclosed drawings.

FIG. 1 shows a diagram of the arrangement of the diverse functional units of the follow-up mechanism and the space attributed thereto, FIG. 2 is a section of a preferred embodiment of the follow-up device according to the invention, FIG. 3 is a top view of the follow up device according to FIG. 1 with the lid taken off, FIG. 4 is another embodiment especially of the arrangement of the angle generator.

As is shown from the diagram according to FIG. 1 within the whole building space 0 there is a support 1 and a flat closed gearing space 3 covered by a lid 2 to be connected to the support 7 and on the other side a motor space 4 and a space 5 for the setting shaft. A space 6 is provided for the angle generator integrated into the follow-up device. 7 and 8 are the motor and the setting shaft. On the latter there is arranged a setting and coupling means 9 or in other words the latter serves for mounting the coupling means 9.

From the section according to FIG. 2 it may be seen that all building parts of the follow-up mechanism are directly or indirectly mounted respectively kept in position by the support 1 and that the lid 2 is connectable to the support 1 by means of a detent. To this purpose at the peripheral surface, of the support 1 there are several notches of which one has been shown at the reference numeral 11.

For axially securing the setting motor 1 2 which is centered by a projecting ring 1 3 at the support 1 there are detenting hooks 14 and 1 5 at the support 1. The gearing of the follow-up mechanism comprises a small toothed wheel 1 6 mounted on the motor shaft 7 which is in engagement with the toothing 1 7 of a spur wheel pair 17/18 and another spur wheel pair 19/20 which is in engagement with its toothing 20 with a toothed wheel 21. In the support 1 axles 22 and 23 are supported as bearing elements for the pairs of toothed wheels 17/18 and 19/20 in operative connection with each other by the toothings 1 8 and 1 9 while the lid 2 takes over the function of axially securing the toothed wheels.

As may also be taken from FIG. 2 the setting shaft 8 is mounted in a suitable long mounting projection 24 being one part with the support 1. Only to be complete it should be mentioned that at the coupling means 9 fastened to the setting shaft 8 there is provided for instance a toothing 25 attributed to the bearing means for the recording pencil and a centering opening 26 as well as a driving slot 27 as a coupling means for the indicator.

The angle generator which has to transform a proportional angular position into an electrical magnitude in the embodiment chosen is immediately arranged coaxially to the setting shaft 8. To this end a plate 28 is connected to the support 1 by a detent (at least three detenting hooks of which one is provided with the reference numeral 29) on which flat resistor lanes 30 and 31 of electrical conducting plastic material are provided. As a tapping means there is a wiper 32 arranged on the thoothed wheel 21 and fastend to the setting shaft 8 in suitable manner at which wiper there are wiping springs not specifically referenced but attributed to each resistor lane 30, 31.The boundary positions of the described follow-up mechanism, as may be seen from FIG. 7, are given by a segment 33 which is one part with the toothed wheel 21 which segment cooperates with corresponding stops 34, 35 which are part of the fixed support 1.

Contact pins 36, 37 and 38 penetrating the plate 28 and conductively connected with the resistor lanes 30, 31 serve to make contact with connecting leads between the resistor lanes 30, 31 and a compensation measuring circuit. Slots 39 in the wall 10 of the support 1 are of such shape that when the lid is put on they serve to take the weight off the connecting leads. Two projectiing eyes 40, 41 arranged at the support 1 and not specifically referenced serve to fasten the follow-up mechanism by means of suitable screws at a corresponding mounting plate 42. Circular adjusting projections 43 serve for centering the follow-up mechanism while various surfaces 44 at the support 1 which, however, have only been partially shown, for instanc the ring-shaped surface 44, serve as mounting surfaces. Of course, one may also think of shaping the support in such a way that the follow-up mechanism can be mounted at the mounting plate 42 or a corresponding housing element of the measuring instrument by a detent.

From FIG. 4 it may be seen that it is possible to provide only one mounting bushing 45 for the setting shaft 8 while the other mounting position 46 is immediately connected to the support 1. The resistor lanes 30, 31 in this case are arranged immediately on the support 1 or on a foil fastened to the support 1.

Claims

1. Follow up mechanism for a compensation measuring device having a setting motor, an angle generator, a reduction gearing and a setting shaft which by means of suitable coupling means is in operative connection with a recording and/or indicating means of the measuring device and which is mounted in a support parallel at least to the shaft of the setting motor, such support taking up also the functional elements of the follow-up mechanism, characterized in that the reduction gearing between the setting. motor (12) and the setting shaft (8) is in the form of spur gears (16, 17, 18, 19, 20, 21) and is arranged in an essentially flat space (3) at one side of the support (1) and in that the setting shaft (8) is mounted in the support (1) so that the end of the setting shaft (8) bearing the coupling means (9) is arranged at the other side of the support (1), and in that the setting motor (12) and the angle generator (30, 31 and 32) are so arranged on the support (1) that its contours are essentially within a space (0) the hight of which is defined by two parallel planes the distance of which corresponds to the length of the setting shaft (8) and in that a lid (2) is attributed to the support (1) at the gearing side for closing the device.

2. Follow-up mechanism according to Claim 1, characterized in that ring-shaped resistor lanes (30, 31) are arranged coaxially to the setting shaft (8) and connected to the support (1) and a wiper (32) is attributed to the resistor lanes (30, 31) to form the angle generator the wiper being attributed to a toothed wheel (21) of the reduction gearing connected to the setting shaft (8).

3. Follow-up mechanism according to Claims 1 and 2, characterized in that the resistor lanes (30, 31) are arranged on a foil connected to the support (1).

4. Follow-up mechanism according to Claim 1, characterized in that the lid (2) is connected to the support by detent means and simultaneously serves for axially securing the pairs of toothed wheels (17, 18 and 19, 20) loosely running on shafts (22, 23) mounted in the support (1).

5. Follow-up mechanism according to Claim 1, characterized in that on the side turned away from the reduction gearing the support (1) has adjusting means (43) and fastening surfaces (44).

6. Follow-up mechanism substantially as herein described with reference to Figures 1-3 or Figure 4 of the accompanying drawings.