GB2089747A

GB2089747A - Endless tracks

Info

Publication number: GB2089747A
Application number: GB8135477A
Authority: GB
Original assignee: Diehl GmbH and Co
Current assignee: Diehl Verwaltungs Stiftung
Priority date: 1980-11-26
Filing date: 1981-11-25
Publication date: 1982-06-30
Also published as: FR2494658B1; DE3044486C2; FR2494658A1; DE3044486A1; GB2089747B

Abstract

A track member, for an endless track for a lightweight vehicle, incorporates a rapidly exchangeable running pad 20 held by a single threaded fastener connection 22, 23, without requiring special securing elements to prevent any unintentional loosening of the connection. A resilient abutment 2.1 is interposed between the running pad and the metal body 1, which layer 2.1 is compressed by tightening of the connection. <IMAGE>

Description

SPECIFICATION Improvements in or relating to endless tracks for vehicles The invention concerns tubular bodies for forming vehicle tracks, which bodies are adapted to receive detachable running pads or metal gripper track elements.

From United States Patent No. 19758 it is known to bolt a running pad to a tubular body to form a track member or tread unit for an endless track. The running pad is vulcanised onto a base sheet. The tubular body consists of a welded structure onto which rubber at the running wheel side is vulcanised. The welded metal structure has two tubes for the reception of connector pins, a web lying between the tubes and two lateral spectacleshaped straps or end bars for stiffening the tubes.

Troughs arise between the tubes, i.e. on both sides of the web. The base sheet has a shape which corresponds to the tubes and the trough, and rests on the straps of the welded metal structure. Thus the metal base sheet and the said parts of the welded structure are in contact. Two screw connections serve as means for fastening the running pad on the tubular body.

Special deformable securing means are necessary for the secure fastening of the screw connections. In the event of fairly often exchanging of the running pads, the securing means, which are vulcanised into the running pad, can no longer prevent a loosening of the screw connections, so that in travel operation the running pads can become detached.

The problem underlying the invention is to enable a running pad or steel grippertrack element to be fastened securely onto a tubular body at slight cost.

According to the present invention there is provided a track member comprising a tubular body to which is secured by fastener means either a resilient running pad bonded to a metal sheet having a base surface, or a metal gripper track element having a base surface, characterised in that an elastomeric abutment is interposed between the tubular body and the base sheet or surface; in that said elastomeric abutment is bonded onto the tubular body or the base surface; and in that the fastener means comprises at least one threaded fastener.

The invention further provides a tubular body having a resilient running pad securable to the tubular body by fastener means, which running pad is bonded onto a base sheet, characterised in that there is presented at the roadway side of the tubular body a concavity bounded by a base and tubular portions of the tubular body, and in which concavity there is disposed an elastomeric abutment defining a recess; in that the base sheet is shaped to correspond to the roadway-side contour of the elastomeric abutment, so as to engage in the recess; in that the elastomeric abutment, interposed between the base sheet and the tubular body, is bonded to the tubular body or the base sheet; and in that the fastener means comprises at least one threaded fastener.

What is surprising about this arrangement of the tubular body and the running pad of the invention is that, as a result of the cumulative spring action of the resilient running-pad and the elastomeric intermediate abutment, an endless track incorporating the tubular bodies and running pads is very smoothrunning; that besides the sprung running-pad connection also steel grippers can be superimposed in sprung manner; and that as a result of the intermediate elastomeric abutment providing a mounting underthe base sheet of the running pad only a single bolt or screw can be employed and the need for additional fastening screws or bolts and their locking means is obviated.

The tubular body preferably has, at the ends of its tubular portions, webs which bound the concavity laterally; and the roadway-side surfaces of the webs and the tubular portions are preferably covered by the elastomeric abutment and serve to support the base sheet or base surface, so that a four-sided form locking fitting of the running pad or track element to the tubular body can be achieved, whereby substantially to relieve the single bolt or screw of stresses in directions transverse to the direction of the axis of the screw or bolt.In particular, the recess prefeably has a flat bottom bounded by part cylindrical surfaces adjacent the tubular portions and by inclined surfaces which increase in width to adjacent the webs; and the base sheet or surface preferably provides a projecting surface portion which is complementary to the flat bottom and which is bounded by part cylindrical surfaces and by inclined surfaces which increase in width. As a result of the running pad engaging partially also over the tubes of the tubular body of the specific surface pressure on the roadway side of the running pad is very low and therefore an increased stability of the running pad exists.

The abutment is preferably bonded to the tubular body because the abutment is almost free from wear, and therefore a single tubular body can be provided successively with running pads as the latter become worn, whereby to minimise replacement costs.

The elastomeric abutment in the concavity is preferably thicker by a multiple than over the roadway-side surface of the tubular portions, the tubular body is preferably provided with a sleeve for the threaded fastener; and between the base sheet or surface and the sleeve there is preferably free space to accommodate distortion of the elastomeric abutment adjacent the sleeve, whereby to enhance the apparent resilience of the running pad, in that, upon the springing-in of the portion of the abutment in that recess, this can give way in the region of the tubular bodies, and the single screw or bolt connection remains secure because upon tightening of said connection said abutment is forced to yield and thereby stress the connection.

The elastomeric abutment is preferably bonded to the tubular body and forms part of a sheath which encloses the tubular body except for lateral surfaces of the tubular body and the webs, and except for apertures to permit the fastener means to engage the tubular body, so as to offer a high detachment strength of the abutment from the tubular body and contribute to a saving in costs, because an elastomeric pad atthe running-wheel side of the tubular body can be provided by the sheath and bonded therewith to the tubular body in one operation.

The base of the tubular body preferably has openings through which the elastomeric abutment extends from a running-wheel side to the roadway side of the tubular body, so as to avoid one-sided accumulaions of heat in the sheath, by making possible a heat flux between the running-wheel side and the roadway side. Partial detachment phenomena, caused by temperature, are thereby substantially avoided.

The base sheet is preferably shaped for an inexpensive production by deep-drawing.

The invention includes a tubular body for a vehicle track, comprising a pair of parallel tubular portions joined by a base, and lateral webs which extend laterally of the body to join the ends of the tubular portions, characterised in that the tubular body is encased in elastomeric material except for lateral faces of the tubular body and apertures to permit a threaded fastener to be inserted into the tubular body and hold a running pad or a metal track element; and in that the elastomeric material provides a recess to receive part of the pad or element.

An embodiment of the invention is shown by way of example in the accompanying drawings, in which: Figure 1 shows a tubular body at the runningwheel side; Figure 2 shows the tubular body with running pad in perspective view; Figure 3 shows the tubular body in accordance with Figure 1 in the cross-section Ill-Ill; Figure4showsthe running pad atthe roadway side; and Figure 5 shows the tubular body with running pad in accordance with the section line V-V indicated in Figures 3 and 4.

The tubular body 1 consists, in accordance with Figures 1 to 5, of cast aluminium and is provided with rubber-mounted pins 1.1. The body 1 comprises a supporting plate or base 1.5, provided with openings 1.2 to 1.4 and with a sleeve 4. The body further comprises transverse tubular portions 5, 6 and lateral webs 7,8 which connect the ends of the portions 5, 6, so that the roadway side of the body defines a concavity.

The tubular body 1 is provided with a sheath 2 which is vulcanised on and which incorporates an abutment 2.1 of a rubber or elastomeric material. A recess 3 in the sheath accommodates a nut 30. The tubular body 1 is covered, save for the eyes 4.1, 4.2, of the sleeve 4 and the lateral outer surfaces of the webs 7,8, completely with the sheath. The abutment 2.1 is disposed in said concavity and provides a resilient layer over the roadway side of the portions 5,6, the webs 7,8, and the base 1.5 which layer in the concavity is thicker by a multiple than over the tubular portions 5, 6 and the webs 7, 8, so as to provide at the roadway side of the abutment 2.1 a recess 11 having a flat bottom 10 bounded by part cylindrical surfaces over the portions 5, 6, and inclined surfaces which increase in width to adjacent the webs 7, 8.

The running pad 20 comprises an elastomeric pad 25 at the roadway side which is bonded onto a base sheet 21 made of steel, and a bolt or screw 23 having a head 22 welded to the base sheet. The pad 20 is shaped so that running wheel side surface of the base sheet is complementary in shape to the roadway side of the abutment 2.1 so as to provide a shaped projecting portion which fits the recess 11.

To fit the running pad 20 or a steel gripper track element (not shown) having a base surface which is complementary in shape to the roadway side of the abutment 2.1 respectively, the relevant part is, as shown in Figure 2, superimposed onto the tubular body 1 and fastened in position by tightening the nut 30 onto the bolt or screw 23 so that the base sheet 21 is pressed largely uniformly against the abutment 2.1 to cause some resilient deformation of the latter.

As shown in Figure 5, a free space 12 is provided between the eye 4.1 and the base sheet 21 to accommodate some of the deformed abutment around the bolt or screw.

For the reliable and arbitrarily repeatable fastening of the running pad 20, therefore, an additional securing or locking means for the screw or bolt connection 23, 30 is not necessary. What is material is also the fact that a single screw connection is adequate for the durable fastening.

Instead of the elastomeric layer 2.1 on the roadway side of the tubular body, an elastomeric layer can be provided on the tubular body side of the base sheet or base surface of the running pad or track element, so that the layer rests directly on the cast aluminium of the tubular body to provide an abutment.

The invention embraces also the use in combination of a roadway-side elastomeric layer on the tubular body andthe aforesaid tubular-body-side elastomeric layer on the base sheet or surface, so that two rubber layers are braced against one another to form the abutment.

The tubular body 1 can, if required, be made of cast steel or may be a welded steel structure.

The elastomeric material or materials may be of rubber and the bonding referred to may be performed byvulcanisation.

Claims

1. A track member comprising a tubular body to which is secured by fastener means either a resilient running pad bonded to a metal sheet having a base surface, or a metal gripper track element having a base surface, characterised in that an elastomeric abutment is interposed between the tubular body and the base sheet or surface; in that said elastomeric abutment is bonded onto the tubular body or the base surface; and in that the fastener means comprises at least one threaded fastener.

2. A track member as claimed in Claim 1,further characterised in that the elastomeric abutment is disposed in a concavity in the roadway side ofthe tubular body, and defines a recess in which a complementary shaped projecting portion of the base surface fits; and in that the tubular body comprises a base and two tubular portions which bound the concavity.

3. A tubular body having a resilient running pad securable to the tubular body by fastener means, which running pad is bonded onto a base sheet, characterised in that there is presented at the roadway side of the tubular body a concavity bounded by a base and tubular portions of the tubular body, and in which concavity there is disposed an elastomeric abutment defining a recess; in that the base sheet is shaped to correspond to the roadway-side contour of the elastomeric abutment, so as to engage in the recess; in that the elastomeric abutment, interposed between the base sheet and the tubular body, is bonded to the tubular body or the base sheet; and in that the fastener means comprises at least one threaded fastener.

4. A track member as claimed in Claim 2, or a tubular body as claimed in Claim 3, characterised in that the tubular body has, at the ends of its tubular portions, webs which bound the concavity laterally; and in that the roadway-side surfaces of the webs and the tubular portions are covered by the elastomeric abutment and serve to support the base sheet or base surface.

5. Atrack member as claimed in Claim 2 or a tubular body as claimed in Claim 3 or 4, characterised in that the elastomeric abutment in the concavity is thicker by a multiple than over the roadwayside surface of the tubular portions; in that the tubular body is provided with a sleeve for the threaded fastener; and in that between the base sheet or surface and the sleeve there is free space to accommodate distortion of the elastomeric abutment adjacent the sleeve.

6. A track member as claimed in Claim 1 or 2, or a tubular body as claimed in Claims 3,4 or 5, characterised in that the elastomeric abutment is bonded to the tubular body and forms part of a sheath which encloses the tubular body except for lateral surfaces of the tubular body and apertures to permit the fastener means to engage the tubular body.

7. A track member or tubular body as claimed in Claim 6 as appended to Claim 4, characterised in that outer lateral surfaces of the webs are exposed.

8. Atrack member as claimed in Claim 2 or a tubular body as claimed in any one of Claims 3 to 7, characterised in that the base of the tubular body has openings through which the elastomeric abutment extends from a running-wheel side to the roadway side of the tubular body; and in that the elastomeric abutment is bonded to the tubular body.

9. A track member or a tubular body as claimed in Claim 4 or in any one of Claims 5 to 8 as appended to Claim 4, characterised in that the recess has a flat bottom bounded by part cylindrical surfaces adjacent the tubular portions and by inclined surfaces which increase in width to adjacent the webs; and in that the base sheet or surface provides a projecting surface portion which is complementary to the flat bottom and which is bounded to part cylindrical surfaces and by inclined surfaces which increase in width.

10. A track member as claimed in any preceding Claim appendent upon Claim 1 or a tubular body as claimed in any one of Claims 3 to 9, wherein the fastener means comprises a single central bolt or screw and a threaded female fastener engageable upon a bolt or screw.

11. A track member as claimed in any preceding claim appendent upon Claim 1 or a tubular body as claimed in any one of Claims 3 to 10, characterised in that the elastomeric abutment comprises a layer of rubber or elastomeric material vulcanised or bonded onto the tubular body.

12. Atrack member as claimed in any preceding claim appendent upon Claim 1, or a tubular body as claimed in any one of Claims 3 to 11, characterised in that the elastomeric abutment comprises a layer of rubber or elastomeric material vulcanised or bonded onto the base sheet or base surface.

13. A tubular body for a vehicle track, comprising a pair of parallel tubular portions joined by a base, and lateral webs which extend laterally of the body to join the ends of the tubular portions, characterised in that the tubular body is encased in elastomeric material except for lateral forces of the tubular body and apertures to permit a threaded fastener to be inserted into the tubular body to hold a running pad our a metal track element; and in that the elastomeric material provides a recess to receive a projecting part of a running pad or track element.

14. Atrack memberortubular body substantially as hereinbefore described with reference to the accompanying drawings.