GB2320090A

GB2320090A - Recording member adjustment

Info

Publication number: GB2320090A
Application number: GB9725645A
Authority: GB
Inventors: Thomas Riester
Original assignee: Mannesmann VDO AG
Current assignee: Mannesmann VDO AG
Priority date: 1996-12-05
Filing date: 1997-12-03
Publication date: 1998-06-10
Anticipated expiration: 2017-12-03
Also published as: GB2320090B; DE19750683B4; DE29621117U1; GB9725645D0; DE19750683A1

Abstract

An adjusting mechanism (54) drives a recording member (48) so that the member is not located in constant geared connection with a driving member. The mechanism (54) is composed of an entrainment member (56), which is mounted to rotate on the support (45) of a recording member and which is in operative connection with an eccentric (55), which is likewise mounted on the support (45). Formed coaxially with the eccentric (55) is click-stop toothing (61 fig.2), in which a pawl (70) formed on the entrainment member 56 engages. The mechanism is self-locking and can be connected in a plug-in manner to the support 45 of the recording member.

Description

1 2320090 Adjusting mechanism for use with a recording mr for recording

charts The invention relates to an adjusting mechanism for use with a recording member in recording charts.

In known mechanisms in the non-actuated state, a support for the recording member or a transmission lever connected by gears to the latter, bears under the action of a spring against a stop and the recording member is actuated by a driving member moving freely.

The prerequisites for the application of such a recording concept are provided for example when the position of the L - L recording member on a recording support is specified by a grid network printed on the recording support, that is to say the recording member or its basic or zero position is to be located on a certain line or parallel or concentric to a line of the grid.

A further adjustment between the recording member and the driving member is necessary, in order that the recording member also actually records the desired bar width, which in many cases has narrow tolerances. That is to say it is necessary to adjust the entrainment position for example of an eccentric or a reciprocating driving member, which is not constantly in engagement with the support of the recording member, in other words moves freely, in which case a lever able to tilt about a pivot point or a carriage guided in parallel may serve as the sippgrt.. With the adjustment to be undertaken, on the one hand, in particular if several bar charts of different width are to be recorded, which are possibly read mechanically, high accuracy is required. On the other hand considerable manufacturing tolerances to be compensated for if the driving member itself is 2 adjusted for example for another recording task and the drive of the recording member recording the bar charts is branched-off solely as an additional use.

An object of the present invention is to provide an adjusting mechanism, which, using components suitable for mass production, can be assembled with the lowest possible resources and which guarantees the simplest possible and rapid adjustment.

According to the invention an adjustment mechanism is provided for the driving connection of a recording member for recording charts particularly for tachcgraDhs of the type where in the non-actuated state, a suppor-for the recording member or a transmission lever connected thereto in a geared manner bears under the action of a spring against a stop and the recording member is actuated by a freely moving driving member; said mechanism comiDrising an entrainment member which is mounted to rotate on the support, the entrainment member being in operative connection with an er-centric which is likewise mounted on the support 'ahd-a--'tachbt gear associated with the eccentric and forming a releasable fastening between the entrainment member and the eccentric.

The invention achieves the ob-4ect set with minimum resources in that only two components able to be made by theinjection moulding technique are required, which can be assembled in a simple manner, that is to say by the holding of one component by the other and by a suitable click-stop and mating connection of one component with the support for the recording member.

Euzthermore, as a result of t.h_e self-locking construction of the adjusting device, no additional means are required for fixing the entrainment member in the adjusted position.

3 An embodiment of the invention will be described in detail hereafter, by way of example only, and with reference to the accompanying drawings, in which:

Figure 1 is a plan view of a recording device used in a tachograph incorporating an adjustment mechanism constructed in accordance with the invention, Figure 2 is an enlarged illustration of the detail A of Figure Figure 3 is a section on sectlion line Y of Figure 2 and Figure 4 is an underneath vi-ew of an entrainment member used in the device shown in Figure 1.

As depicted in Figure 1 a recording device 2 is located on a mounting plate 1, in a tachograph. In this case, the view of the recording device 2 i.&-,from a chart disc 3 shown partly in Figure 1 or frbld,-t-fe-,rdcc;rding plane. This means that the recording device 2 is constructed such that it fits in a relatively narrow installation space between the recording plane and the mounting plate 1. The reference numerals 4, 5, 6 and 7 designate holders preferably integrally formed by injection moulding on the mounting plate 1. The holders 4, 5, 6, 7, have resilient claws acting in opposition and not shown in detail. In this case, the pair of holders 4, 5 serves for attaching a guide rod 8 of the device 2, while the other pair of holders 6, 7 mount a cam shaft 9 to be described in more detail hereafter. The camshaft 9 is crMen,by a servo-motor (not shown) by way of a suitable geared connection, of which only one gear 10, preferably a helical gear and an arrow P indicating the flow of force are illustrated in Figure 1. Two recording carriages 11 and 12 are mounted to slide on the guide rod 8. The gu-'de rod 8 is secured in the axial 4 direction by suitable walls integrally formed on the holders 4 and 5. The recording carriages 11 and 12, produced as injection moulded parts, are constructed so that the respective support points on the guide rod 8 are at the largest possible distance apart in order to reduce the tilting angle. Each recording carriage 11, 12 has an integral arm 13, 14, which engages with a finger 15, 16 in the region of movement of the cam shaft 9. Recording members in the form of styli 1-7, 18 are securely connected to the arms 13, 14 by pressing-in. In this case, the stylus 17 is the speedrecording member of the tachograph, whereas the stylus 18 serves as a multi-trace recording member. Also mounted on the arms 13, 14 are springs 19, 20 supplying the recording force. One leg 21, 22 of each spring 19, 20 is supported an the cam shaft 9, and another leg 23, 24 bears against a bracket 25, 26 integrally formed on the arm 13, 14.

Journals 27 and 28 serve for locating and centring of the springs 19, 20. Hooks 29, 30 integrally formed on the arms 13, 14, serve for the lateral fixing of the spring legs 21, 22.

The recotding:-ca-rriage 11 is provided with a rack or.toothing 31 engaging with a gear wheel 32 is mounted on a shaft 34 attached to the mounting plate 1. A further gear wheel 33 on the shaft 34 meshes with a pinion 35. The pinion 35 is attached to a shaft 36 passing through the mounting plate 1 and coupled to a stepping motor located on the opposite side of the mounting plate 1. The motor is controlled in a speed-dependent manner. In a similar manner, the recording carriage 12 is in operative connection by way of a rack or toothing 37 and a gear train 38, 39, 40, 41, 42 with a stepping motor located on the opposite side of the mounting plate 1. The latter is controlled so that the recording carriage 12 and thus the stylus 18 is moved to and fro in dependence on a measured value over several recording areas of the chart disc 3.

The cam shaft 9 has two axial-spaced earns 43 and 44 associated with the recording carriages 11 and 12, which cams are offset with respect to each other in the direction of rotation of the cam shaft 9. Due to the rotation of the cam shaft 9, on account of the aforedescribed construction, either both styli 17 and 18 are lifted from the recording plane, which is necessary when. removing or inserting a chart disc 3, or, whilst the stylus 17 recording the speeds rests an a chart disc 3, due to a tilting movement of the cam shaft 9 within a certain angular range, the multi-trace stylus 18 can be lowered and raised again for recording in the different recording areas.

A support in the fo= of a two-a=ed lever 45, serves to mount a further recording member 6. 17he lever 45 is pivotably mounted on a shaft 47 fastened on the mounting plate 1. In this case, the recording member 46 takes the form of a leaf spring attached to the lever 45 and provided with a stylus 48. A tension spring 49 holds the lever 45 in a basic position against an adjustable stop 50. In this posj-tlon, the stylus 48 records a base or zero line 51.,,Aii-=.en-cion 52 integrally formed on the lever 45 penetrates an opening 53 in the mounting plate 1 and bears against the opposite side of the mounting plate 1. In this way, the lever 45 can be mounted without additional axial securing means on the shaft 47.

The lever 45 supports an adjusting mechanism 54, which consists essentially of an entrainment member 56 adjustable by means of an eccentric 55. The adjusting mechanism 54 will now be described in detail in conjunction with Figures 2, 3 and 4. In the position shown in Figure 1, the entrainment member 56 or a guide projection 57 integrally formed on the entrainment member 56 is in entrainment contact with a journal 58, which is integrally formed on an arm 59 of the recording carriage 12. If, in this position of the recording carriage 12, the driving 6 stepping motor is controlled so that the recording carriage 12, with respect to the multiple recording region, carries out an excess stroke in the direction of the centre of the chart disc, then according to the control of the stepping motor, bar charts 60 of different width can be recorded by the recording member 46. However, it is also clear that the entrainment position of the recording device 2, illustrated in Figure 1, must be adjusted with high accuracy.

As is apparent from Figures 2 and 3, the adjusting mechanism 54 is located directly on the two-armed lever 45. This means that the eccentric 55, which together with a disc 62 supporting click-s"--op toothing 61 forms a component mounted to rotate on the lever 45 by means of an integrally formed journal 63. The is entrainment member 56 is mounzed to rotate on the lever 45 and locked to the latter. Serving for this purpose is a split pin 64 provided with a click-stop edge, which engages in a recess 65 formed in the lever 45. The entrainment member 56 is furthermore secured in the axial-_!irection by two bolts 66 and 67 integrally formed on.thc--17ever-.45. An enlargement 68 formed on the lever 45 serves as a support for the entrainment member 56. An integrated hook 69 on the lever 45 serves for the suspension of the tension spring 49. A pawl 70 formed on the entrainment member 56, is operably associated with the click-stop toothing 61. Figures 2 and 3 also show that the components of the adjusting mechanism 54, namely the eccentric 55 and the disc 62 as well as the entrainment member 56 are fixed on the lever 45 in a selflocking manner. In this case the eccentric 55 is constructed with a smaller diameter than the disc 62 and the entrainment member 56 engages over the disc 62 by means of a recess 71. A cross slot 72 for applying a tool is associated with the eccentric 55. A slide 73 formned in the entrainment member 56, can come into operative connect,--Jon with the eccentric 55.

7 It should also be emphasized that the pawl 70 integrally formed on the entrainment member 56 and the click-stop toothing 61 formed on the disc 62, which supports the eccentric 55, form a ratchet gear, which on account of a corresponding pitch of the click-stop toothing 61 on the one hand allows an adequately sensitive adjustment, on the other hand serves for the mutual fixing of the eccentric 55 and entrainment member 56. With unequal spacing of the click- stop toothing 61 in the chosen embodiment, equal adjusting steps of the guide projection 57 can be achieved, which simplifies the adjustment. Furthermore it should also be mentioned that the aforedescribed adjusting mechanism can also be located on an intermediate or transmission lever in the gear train for a recording member. In this case it is conceivable that the recording member, such as is customary for example in tachographs for recording the working times of assistant drivers, records in another recording plane than the remaining recording members.

-....==- -- 1, ' 1.

8

Claims

Claims

An adjustment mechanism for the driving connection of a recording member for recording charts, particularly for tachographs, of the type where in the non-actuated state, a support for the recording member or a transmission lever connected thereto in a geared manner bears under the action of a spring against a stop and the recording member is actuated by a freely moving driving member; said mechanism comprising an entrainment member, which is mounted to rotate on the support, the entrainment member being in operative connection with an eccentric, which is likewise mounted on the support and a ratchet gear associated with the eccentric and forming a releasable fastening between the entrainment member and the eccentric.
2. An mechanism according to Claim 1, wherein the entrainment member is mounted and secured axially on the support by means of a click-stop connection.
3. A mechanism acQQ2ding to Claim 1, wherein the eccentric is 20 formed on -aeli-se -,supporting click-stop toothing and a pawl integrally formed on the entrainment member engages with the click-stop toothing.
4. A mechanism according to Claim 3, wherein the entrainment member is provided with a recess for axial securing of the disc.
5. A mechanism according to Claim 3 or 4, wherein the disc has means for receiving a tool serving for adjustment.
6. A mechanism according to Claim 3 or 5, wherein the clickstop toothing has an unequal spacing.
7. An adjustment mechanism substantially as described herein 30 with reference to and as illustrated in any one or more of the Figures of the accompanying drawings.
8. A tachograph incorporating an adjustment mechanism according to any one or more of the preceding claims.