GB1565753A - Measuring instruments - Google Patents

Description

(54) IMPROVEMENTS IN MEASURING INSTRUMENTS (71) We, VDO ADOLF SCHIND LING AG, of 103 Grafstrasse, Frankfurt/ Main, West Germany, a body corporate organized according to the laws of West Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to an assembly of measuring instruments for motor vehicles, having a plurality of measuring instruments and a housing common to all the measuring instruments electrical connecting elements being connected between the cover or lid formed with viewing apertures and the base of the measuring instruments, these electrical connecting elements being in plug-in connection with contacts secured to the housing.

Measuring instrument assemblies are already known wherein the individual measuring instruments are arranged in a common housing provided with a removable viewing disc and are fixed in the housing by screw connections actuated from the rear side of the housing. Such instrument assemblies have the disadvantage that the rear side of the housing must be accessible for replacing the measuring instruments. If, as is the case in a motor vehicle, this access is not available, then the housing containing the measurement instruments must be removed from its retaining means, for example the instrument panel, and only thereafter is it possible to remove the measuring instrument or instruments from the housing, or to insert a replacement instrument or instruments into the housing.Thus, with these arrangements, replacement of the measuring instrument is extremely inconvenient and time-consuming, and as a result expensive.

It is an object of the present invention to overcome the above disadvantage of the known measuring instrument assemblies by providing a measuring instrument assembly wherein replacement of a measuring instrument can be carried into effect rapidly and without difficulty.

According to the present invention there is provided an assembly of measuring instruments including: a plurality of measuring instruments; a common housing box closed with a cover having viewing apertures for the individual measuring instruments; plug and socket connections at the rear side of each measuring instrument and the bottom of the housing box; and means for latchingly connecting the measuring instruments with the bottom of the housing or the cover.

Due to these measures it becomes possible, subsequent to removal of the housing cover, to remove the individual measuring instruments from the housing base or cover readily and rapidly and without the assistance of any tool, or to apply the same on the housing base or housing cover. A special advantage is that the latching means can without difficulty be adapted to the desired mechanical requirements Preferably, each measuring instrument housing is provided with an annular bead and there is provided at the base or cover of the common housing a plurality of resilient tongues distributed on a circle and projecting obliquely inwards. The annular bead may (if the measuring instrument housing is made from metal) be simultaneously formed-on when manufacturing the housing.The resilient tongues (which may be formed on an annular base member made of plastics material) may be manufactured with said base member in an injection moulding process. The retaining force of such a connection can additionally be further improved by forming a latching nose on to the free end of each tongue.

Preferably there are provided at each measuring instrument housing two resilient projections located radially opposite each other and, at the base or at the cover of the housing, at least two claw-like retaining arrangements located radially opposite each other.

It is true that such a construction is slightly more expensive from the manufacturing point of view than the one previously described, but it has the advantage that the securing of the measuring instrument at the housing is able to cope with maximum mechanical stresses. The claw-like retaining means are preferably formed onto an annular base member made of plastics material.

In addition to the advantage from the aspect of manufacturing techniques afforded by such a solution, it considerably facilitates attachment of the retaining means to the housing. To ensure rapid and as far as possible effortless installation and extraction of the measuring devices, it is preferable to provide each of the projections with manipulating or grasping means.

The contacts secured to the housing may be latchingly connected by the electrical connecting elements of each measuring instrument. Such an arrangement provides the advantage over the above described latching connecting means by reason, that the electrical connection supplementary retaining force acts from the housing on the measuring instrument. For the same reason, it is preferable to provide the viewing aperture in the cover with inwardly projecting stop rings on which the measuring instrument housing is able to bear.

If it has been ensured that the individual measuring systems of the measuring instrument are adequately protected against mechanical damage, in particular during installation and removal of a measuring instrument, then each measuring instrument housing can be substituted by retaining means receiving the measuring system. In this manner, the cost of the measuring instrument can in many cases be further reduced.

The present invention will now be described in greater detail by way of example with reference to the accompanying drawings, wherein: Figure I is a perspective view of one preferred form of assembly of measuring instruments; Figure 2 is a partially sectioned lateral elevation of one of the measuring instruments shown in Figure 1, fixed in the housing of the instrument assembly; Figure 3 is a partially sectioned lateral elevation of one of the measuring instruments shown in Figure 1, secured in the housing of the instrument assembly in an alternative manner; and Figure 4 is a plan view of a detail of the measuring instrument shown in Figure 3.

Referring first to Figures 1 and 2, the assembly of measuring instruments comprises a rectangular box-like housing 1 of relatively flat form, sealed at its front face with a cover or lid 2. Formed in the cover 2, which is secured to the housing 1 by screws 3, are circular windows 4 constituting viewing apertures rearwardly of which are located the individual measuring instrument 5.

Each measuring instrument 5 is, with its housing 6 latchingly connected to a base 7 of the rectangular housing 1. The latch connection is effected by six resilient tongues 8 (only two of which are visible) extending from an annular base member 9 made from plastics material.

The base member 9 is retained by means of screws to the base 7 of the rectangular box-like housing 1. At their free ends, the tongues 8 are each provided with a latching nose 10. The tongues 8 engage by means of their latching noses 10 an annular bead 11 stamped into the housing 6.

Each measuring instrument 5 has two electrical connecting elements in the form of threaded bolts 12 projecting through associated apertures in the housing base 7 and, there, connected with spring contacts 13.

This connection also constitutes a latching connection. At its front end face, the measuring instrument 5 bears on a stop ring 14 adhesively secured to the cover 2.

On replacing a measuring instrument 5, the latter is, subsequent to removal of the cover 2, drawn out of its retaining means and then the new measuring instrument is pushed into the retaining means until the tongues 8 snap over the annular bead 11, after which the cover 2 is re-applied.

Referring now to the embodiment shown in Figures 3 and 4, there are provided for the latch connection of the housing 6 and the base 7 two resilient projections 15 located radially opposite to each other and which are for example stamped or punched out of the metal housing 6. The projections 15 engage rearwardly of two claw-like retaining arrangements 16 shaped on to an annular base member 17 made of plastics material secured to the base 7 by means of screws. Through a slot 18 formed in each claw-like retaining arrangement 16 projects an extension of the projection 15 in the form of a handle 19. On replacing a measuring instrument secured in this manner, the two projections 15 are displaced via the manipulating means 19 in the direction towards the housing 6 and thereupon the measuring device is pulled out of the retaining arrangement.

Subsequently, the new measuring instrument is pushed into the retaining arrangement, the projections 15 being displaced by the claw-like retaining means 16 towards the housing 6 and spreading-apart in the housing end position below the claw undersides.

WHAT WE CLAIM IS: 1. An assembly of measuring instruments including: a plurality of measuring instruments; a common housing box closed with a cover having viewing apertures for the individual measuring instruments; plug and socket connections at the rear side of each measuring instrument and the bottom of the housing box; and means for latchingly connecting the measuring instruments with the bottom of the housing or the cover.

2. An assembly of measuring instruments according to claim 1, wherein each measuring instrument housing is provided with an annular bead and there is provided at the base or cover of the common housing, a plurality of resilient tongues distributed on a circle and projecting obliquely inwards.

3. An assembly of instruments according to claim 2, wherein the resilient tongues are formed on an annular base member made of plastics material.

4. An assembly of measuring instruments according to claim 2 or 3, wherein the free end of each tongue is provided with a latching nose.

5. An assembly of measuring instruments according to claim 1, wherein there are provided firstly, on each measuring instrument housing two resilient projections located radially opposite each other, and secondly, at the base or cover of the housing at least two claw-like retaining means located radially opposite each other.

6. An assembly of measuring instruments according to claim 5, wherein the projections are provided with manipulating means.

7. An assembly of measuring instruments according to claim 5 or 6, wherein the claw-like retaining elements are formed on an annular base member made of plastics material.

8. An assembly of measuring instruments according to any one of the preceding claims, wherein the contacts secured to the housing are adapted to be latchingly secured to the electrical connecting elements of each.

measuring device.

9. An assembly of measuring instruments according to any one of the preceding claims, wherein the viewing apertures in the cover are provided with inwardly projecting stop rings on which the measuring device housings bear.

10. An assembly of measuring instruments according to any one of the preceding claims, wherein each measuring instrument housing is substituted by retaining means receiving the measuring system.

11. An assembly of measuring instruments substantially as herein described with reference to and as illustrated in Figures 1 Fr ' < and 4 of the accomand 2 or Figures 1, 3 and 4 of the accom- panying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (11)

**WARNING** start of CLMS field may overlap end of DESC **. housing 6 and spreading-apart in the housing end position below the claw undersides. WHAT WE CLAIM IS:

1. An assembly of measuring instruments including: a plurality of measuring instruments; a common housing box closed with a cover having viewing apertures for the individual measuring instruments; plug and socket connections at the rear side of each measuring instrument and the bottom of the housing box; and means for latchingly connecting the measuring instruments with the bottom of the housing or the cover.

2. An assembly of measuring instruments according to claim 1, wherein each measuring instrument housing is provided with an annular bead and there is provided at the base or cover of the common housing, a plurality of resilient tongues distributed on a circle and projecting obliquely inwards.

3. An assembly of instruments according to claim 2, wherein the resilient tongues are formed on an annular base member made of plastics material.

4. An assembly of measuring instruments according to claim 2 or 3, wherein the free end of each tongue is provided with a latching nose.

5. An assembly of measuring instruments according to claim 1, wherein there are provided firstly, on each measuring instrument housing two resilient projections located radially opposite each other, and secondly, at the base or cover of the housing at least two claw-like retaining means located radially opposite each other.

6. An assembly of measuring instruments according to claim 5, wherein the projections are provided with manipulating means.

7. An assembly of measuring instruments according to claim 5 or 6, wherein the claw-like retaining elements are formed on an annular base member made of plastics material.

8. An assembly of measuring instruments according to any one of the preceding claims, wherein the contacts secured to the housing are adapted to be latchingly secured to the electrical connecting elements of each.

measuring device.

9. An assembly of measuring instruments according to any one of the preceding claims, wherein the viewing apertures in the cover are provided with inwardly projecting stop rings on which the measuring device housings bear.

10. An assembly of measuring instruments according to any one of the preceding claims, wherein each measuring instrument housing is substituted by retaining means receiving the measuring system.

11. An assembly of measuring instruments substantially as herein described with reference to and as illustrated in Figures 1 Fr ' < and 4 of the accomand 2 or Figures 1, 3 and 4 of the accom- panying drawings.