DE3325838C1

DE3325838C1 - Device for the tensioning of a chain

Info

Publication number: DE3325838C1
Application number: DE19833325838
Authority: DE
Inventors: Robert 8000 München Maier; Georg Dipl.-Ing. 8021 Icking Summerer
Original assignee: Joh Winklhofer and Soehne GmbH and Co KG
Current assignee: Joh Winklhofer Beteiligungs GmbH and Co KG
Priority date: 1983-07-18
Filing date: 1983-07-18
Publication date: 1985-01-03

Abstract

Device for the tensioning of a chain with a tensioning head on a piston which is displaceable in a housing fixed to the device, with a spring which endeavours to displace the piston out of the housing and with a toothed ratchet limiting the inwards movement of the piston into the housing to the height of a tooth, characterised in that the toothed ratchet has two axially aligned sleeves, rotatable relative to one another, one of which is supported in the housing and the other in the piston, and that these sleeves are provided with rows of teeth pointing to one another and running in a complementary helix shape and with slide surfaces pointing to one another and running in a mutually complementary helix shape.

Description

Die beiden Hülsen 14, 16 sind axial ausgerichtet Die Hülse 16 ist in dem Gehäuse 8 verdrehbar und damit relativ zu der Hülse 14 verdrehbar, die ihrerseits im Hohlkolben 6 abgestützt ist. Die aufeinander zu weisen- den Stirnflächen der beiden Hülsen 14, 16 sind mit komplementär wendelförmig verlaufenden, aufeinander zu weisenden Zahnreihen 34, 36 versehen. Außerdem weisen die Hülsen 14, 16 Ausnehmungen auf, die gegensinnig zu den Zahnreihen 34,36 komplementär wendelförmig verlaufend, aufeinander zu weisende Gleitflächen 38,40 bilden. The two sleeves 14, 16 are axially aligned. The sleeve 16 is rotatable in the housing 8 and thus rotatable relative to the sleeve 14, which in turn is supported in the hollow piston 6. The to be pointed to each other- the end faces of the two sleeves 14, 16 are complementary helically extending one on top of the other To be pointed rows of teeth 34, 36 are provided. In addition, the sleeves 14, 16 have recesses on, which run in the opposite direction to the rows of teeth 34,36 complementary helically, Form facing sliding surfaces 38,40.

Die Vorrichtung arbeitet in folgender Weise: Wird ein Druck auf den Spannkopf 2 ausgeübt, so greifen nach einem gewissen Hubweg die Zahnreihen 34, 36 ineinander und verhindern ein weiteres Ausweichen des Spannkopfes 2. Läßt der Druck auf den Spannkopf 2 nach, so kann der Spannkopf 2 so weit ausfahren, daß die Gleitflächen 38 und 40 einander berühren. Wegen der wendelförmigen Ausbildung der Gleitflächen 38,40 entsteht aus der Axialbewegung eine Verdrehung der Hülsen 14, 16 gegeneinander um ein gewisses Maß, wodurch die Zahnreihe 36 entsprechend verstellt wird. The device works in the following way: If a pressure is applied to the When the clamping head 2 is exercised, the rows of teeth 34, 36 engage after a certain stroke into each other and prevent the clamping head 2 from moving further on the clamping head 2, the clamping head 2 can extend so far that the sliding surfaces 38 and 40 touch each other. Because of the helical design of the sliding surfaces 38, 40 results in a rotation of the sleeves 14, 16 relative to one another from the axial movement by a certain amount, whereby the row of teeth 36 is adjusted accordingly.

Wird dann auf den Spannkopf 2 wieder ein Druck ausgeübt, kann er nur noch um ein Maß in das Gehäuse 8 ausweichen, das der nunmehr verdrehten Stellung der Zahnreihe entspricht.If pressure is then exerted again on the clamping head 2, it can only move into the housing 8 by an amount that is the now rotated position corresponds to the row of teeth.

Bei der Montage wird in der Darstellung der Fig. 1 durch Angriff an den Zapfen 20 die Gleitfläche 40 nach links verdreht, so daß sie an die Gleitfläche 38 angreift und dadurch den Hohlkolben 6 und damit den Spannkopf 2 zurückzieht. During assembly, in the illustration of FIG. 1, by attack on the pin 20, the sliding surface 40 is rotated to the left, so that it is against the sliding surface 38 engages and thereby pulls the hollow piston 6 and thus the clamping head 2 back.

Eine andere vorteilhafte Montage ist dann möglich, wenn an der inneren Stirnseite des Gehäuses 8 eine Verzahnung (ein Zahn) angebracht ist, die mit einer entsprechenden Verzahnung der Hülsenstirnseite (z. B. einem Teil der Abstützfläche 30) zusammenwirkt, so daß in einer Drehrichtung das Gehäuse 8 und die Hülse 16 drehfest verbunden sind (bei Montage), während die Hülse 16 sich beim Auseinanderfahren der Vorrichtung gegen das Gehäuse 8 verdrehen kann. Another advantageous assembly is possible if on the inner Front side of the housing 8 a toothing (a tooth) is attached, which with a corresponding toothing of the sleeve face (e.g. part of the support surface 30) cooperates so that the housing 8 and the sleeve 16 are non-rotatable in one direction of rotation are connected (during assembly), while the sleeve 16 is when the Can rotate the device against the housing 8.

Wegen der verhältnismäßig fein unterteilten Zahnreihen 34, 36 ist eine sehr genaue Anpassung des Spannkopfs 2 an den jeweiligen Kettenzustand möglich, was einen besonders ruhigen Lauf der Kette und dementsprechend eine Erhöhung ihrer Lebensdauer zur Folge hat. Because of the relatively finely divided rows of teeth 34, 36 is a very precise adaptation of the clamping head 2 to the respective chain condition is possible, resulting in a particularly smooth run of the chain and, accordingly, an increase in its Service life.

Da die beiden Hülsen 14, 16 gleichartig ausgeführt sein können, ist die Fertigung besonders kostensparend. Since the two sleeves 14, 16 can be designed in the same way, is the production is particularly cost-saving.

Möglich ist aber auch eine unterschiedliche Ausbildung der Hülsen 14, 16, insbesondere hinsichtlich der Länge der Zahnreihen 34,36.However, a different design of the sleeves is also possible 14, 16, in particular with regard to the length of the rows of teeth 34, 36.

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Claims

Claims: 1. Device for tensioning a chain with a Clamping head (2) on a piston (6) which is displaceable in a housing (8) fixed to the device is, with a spring (32), which urges the piston (6) out of the housing (8) seeks, and with one the Hincinbewegung of the piston (6) in the housing (8) on the Height of a tooth limiting ratchet, the two axially aligned, relatively has mutually rotatable sleeves (14, 16), one of which in the housing (8) and the other is supported in the piston (6), characterized in that the sleeves (14, 16) with complementary helical rows of teeth pointing towards one another (34, 36) and with oppositely complementary helically extending one on top of the other to be pointed sliding surfaces (38,40) are provided.

2. Apparatus according to claim 1, characterized in that the in the housing (8) supported sleeve (16) an axial through the housing (8) protruding, by a tool or by hand rotatable pin (20).

3. Device according to one of the preceding claims, characterized in that that the spring is supported on bottom parts (40, 42) of the sleeves (14, 16) Coil spring (32) is

4. Device according to one of the preceding claims, characterized in that the two sleeves (14, 16) are identical.

The invention relates to a device according to the preamble of Claim 1.

In a known from US-PS 23 95332 device of this type the housing is formed by two overlapping sleeves, with in the end face a threaded bolt carrying a clamping head is screwed into one sleeve and an arm is attached to the outer end face of the other sleeve, which is around a stationary pin is pivotable. The clamping head is in turn on a hinged a stationary pin pivotable carrier of a belt tensioning wheel. A helical spring encompassed by both sleeves seeks to urge the two sleeves apart and thus to rotate the sleeve having the internal thread. On this latter one Sleeve there are springs with bends that fit into the axial teeth of the other sleeve intervention. Therefore, although the device can push out the clamping head; the clamping head however, it can only be pushed in by one tooth height.

In a device known from DE-AS 1450801 similar There is a radial pin on the piston that turns into a helical one Row of teeth can engage in a sleeve supported in the housing. The entire, respectively on the clamping head pressing force of the chain that pushes the clamping head into the housing seeks to push, must be absorbed by the pin and the helical toothing.

Therefore, the pen must be made solid, and accordingly the helical toothing must be coarse, which means that the Pin is relatively large from one tooth to the next.

N, 'itli clcr DE-AS 17 75273 is again a similar Vor r i (ung known, the one supported in a fixed housing, rotatable spindle screwed into a sleeve fixedly arranged in a piston; the piston carries while doing the clamping head.

The object of the invention is to provide a device according to the preamble of claim 1, which is easy to manufacture and a finer toothing allowed so that the jumps from tooth to tooth can be kept small.

The solution to this problem is given in the characterizing part of claim 1.

The helical rows of teeth pointing towards each other on both sleeves can have a relatively fine tooth pitch because always support several teeth against each other. The wall thickness also needs to be accordingly the pods not to be excessively large. It is only essential that in every angular position the two sleeves always meet several teeth. Therefore, the Rows of teeth are limited in length.

The oppositely complementary helically extending one on top of the other The sliding surfaces to be pointed ensure that the two sleeves over the axial distance the sliding surfaces can move apart axially until the sliding surfaces touch; then the axial movement of the sleeves is superimposed on one another in a twist the sleeves against each other until this movement is stopped by the counterpressure of the chain will.

In order to bring the clamping head as close as possible to the housing during assembly and to be able to hold onto it, an embodiment according to claim 2 is preferably provided.

A structurally particularly simple arrangement of the suspension is shown in Claim 3 stated.

The training according to is particularly advantageous from a manufacturing point of view Claim 4.

The invention is illustrated below using an exemplary embodiment Notes on the drawings described.

F i g. 1 shows a device in cross section.

F i g. 2 shows the device according to FIG. 1 in line of sight II the F i g 1.

3 shows the sleeve supported in the housing as an individual part.

A clamping head 2 is placed on a support plate 4, which is of a Hollow piston 6 is carried. The hollow piston 6 engages in a housing 8, which is about is to be mounted in a frame of a chain drive, including mounting holes 10, 12 on the housing 8 are used. In the hollow piston 6 is a sleeve 14 and in the housing 8 a sleeve 16, which is essentially designed in the same way, is supported. The one in the case 8 supported sleeve 16 has an axial, protruding through the housing 8, in its End face with a screwdriver slot 18 provided pin 20.

On the outside of the housing 8, the pin 20 is provided with an annular groove 22 provided, in which a snap ring 24 engages, which (in F i g. 1 and 2) under the boundary surface 26 of the housing 8 and thus the sleeve 16 on the housing holds. In the interior of the housing, the pin 20 can be enclosed by a sealing ring 27 be. The sleeves 14, 16 have support surfaces on their end faces facing away from one another 28, 30 for a helical spring 32 that pulls the clamping head 2 out of the housing 8 urge seeks.