AU606662B2

AU606662B2 - Roller mounting for track-guidable vehicles

Info

Publication number: AU606662B2
Application number: AU13207/88A
Authority: AU
Inventors: Herbert Mehren; Siegbert Sawatzky; Hans J. Walloschek
Original assignee: Daimler Benz AG
Current assignee: Daimler Benz AG
Priority date: 1987-03-21
Filing date: 1988-03-17
Publication date: 1991-02-14
Anticipated expiration: 2008-03-17
Also published as: DE3709421C1; AU1320788A

Description

~Z~Yi3a ii i- i I S F Ref: 52454 FORM COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE: Class Int Class Complete Specification Lodged: Accepted: Published: This do me 8 i cntkains the amslPublished i fntide under Priority: Se(,.ion t d Is correct for Rated Ap r ir! Related Art:

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0 Name and Address of Applicant: r ul Daimler-Benz Aktlengesellschaft Stuttgart-Unterturkheim FEDERAL REPUBLIC OF GERMANY Address for Service: Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Complete Specification for the invention entitled: Roller Mounting for Track-Guidable Vehicles The following statement is a full description of this Invention, including the best method of performing it known to me/us 5845/4 f Roller mounting for track-guidable vehicles The invention relates to a roller mounting for trackguidable vehicles and particularly, but not exclusively track-guidable omnibuses, comprising a predetermined breaking point or predetermined deformation point for the mounting track roller and comprising a deformation sensor in the form of an electrically insulated retained conductor which bridges over the predetermined breaking or deformation point mechanically and which breaks when i deformed, as is apparently known for example from German Offenlegungsschrift 31 03 488.

In the case of track guidable omnibuses a collision of the tracking rollers with obstacles nea.r to the ground can never be fully excluded, particularly if omnibuses of this type are also subjected to non-tracked use. In order to protect the steering linkage of the steerable vehicle axles from consequent damage, a predetermined breaking point is provided in the roller mounting. In the earlier but not previously published German Offenlegungsschrift 37 04 517 (currently still Patent Application P37 04 517.2-21) there is also provided, in addition to a predetermined breaking point, a predetermined deformation point in the form of a frictionally clamped and rotatable plug-in connection inside the roller mounting. Not every collision between the tracking rollers and obstacles results in deformation or breaking of the mounting. For this reason as break sensor in the form of a loop of wire which traverses the predetermined breaking point and which tears 'in half when breaking is provided in the reference cited in the introduction, In this way a breaking in the roller mounting can be indicated visually and/or acoustically within the perception range of the vehicle driver by means of a circuit arrangement. In practice the design of such a break indicator in the region of the roller mounting appeared such that a thin insulated wire was bonded to the outsi 0 e of the roller mounting in the region of the predetermined breaking point. The disadvantage with this -2 design is that, despite a certain possibility for protecting the exposed loop of wire by way of a bonded-over protective strip, the wire loop can be easily damaged by fitting operations during adjustment of such tracking rollers or, during operation, by strips on branches lying around or by similar soft road obstacles.

Moreover, an essentially exposed loop of wire is easily covered by wetness particularly salt water, so that a current passage is maintained despite the loop of wire breaking. On the other hand, salt water has a corrosive effect on very thin wire loops so that soon the entire crosssection has corroded through. At the same time it is conceivable that an insulation can become easily brittle. A further disadvantage of the known break indicator or the corresponding sensor is that it is only relatively Stroublesome to use; the quality of such a break sensor depends very much on the care applied during use.

The present invention seeks to provide a break sensor and its arrangement to such an extent that it can be used in a simple, quick and functionally reliable manner and is protected from external mechanical or corrosive influences.

According to the present invention there is provided roller mounting for track-guidable vehicles, including a predetermined breaking and/or predetermined deformation region and comprising a deformation sensor in the form of an electrical conductor, the electrical conductor being electrically insulated from the mounting, which conductor bridges the predetermined breaking or predetermined deformation regions mechanically and which deformation sensor breaks when deformed, wherein there is provided in the mounting a bore which traverses the predetermined breaking or predetermined deformation region and into which bore the deformation S sensor is Insertable, the deformation sensor comprising a frangible breaking piece bearing the electrical conductor.

Owing to the break or deformation sensor being arranged in a bore, the sensor is protected against unintentional mechanical damage; also, moisture or salt water can scarcely reach the bore. Owing to the break or deformation sensor being designed as a separate pln-shaped.

r 3 structure, it can be used manually in a quick and simple manner, the reliable operation of the sensor is not dependent on any care taken during use.

The invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows a plan view of a track-guidable omnibus during untracked use, Figure 2 shows a cross-section taken at right angles to the direction of travel, through the roller mounting at IO the outer end of the left support arm, Figure 3 shows an enlarged view of detail III indicated by an oval dot-dash line, Figure 4 shows a longitudinal section through the A sensor according to Figure 2 or 3 in a detail view, Figure 5 shows another exemplary embodiment of a break sensor in a detail view, and Figure 6 shows the application of break sensor to a modified roller mounting, The omnibus 1 which is partly shown in Figure 1 has a I<D steerable front axle 2. Transverse guide rollers 6 are mounted on both sides of the vehicle in a contact position relative to the vehicle wheel 3 by means of support arms 4 which extend forwardly around the steerable vehicle wheels 3. The transverse guide rollers 6 are arranged near to the ground and extend above the vehicle by approximately 5 cm on both sides. During tracked use of the omnibuses the transverse guide rollers cooperate with laterally mounted transverse guide webs 26, one of which is indicated by a dot-dash lines in Figure 2. During untracked use of the 4 o0 omnibuses it may happen when reversing, or turning into a stopping bay or during evading manoeuvres in confined conditions that the laterally projecting transverse guide rollers 6 during extreme cornering the transverse guide roller projects laterally to a particularly great extend on the inside of the bends collide with road surface obstacles. In this case it should be taken into consideration that firstly the attention of the vehicle driver is distracted somewhat by the surface obstacles, 4 secondly, the vehicle driver also needs to become accustomed to a certain extent to the transverse guide rollers projecting forwardly and laterally in the are immediately in front of the front wheel, In open road traffic such surface obstacles likely to cause collisions can be, for example, gutters or blocks of stone for defining parking prohibitions or as shown in Figure 1tree stumps 5. The latter can cause collisions with the transverse guide roller on the right hand side, the side of 1O the vehicle remote from the driver, during evading manoeuvres on roads, as indicated in Figure 1. In such circumstances a collision can take place even at a relatively high travelling speed. During reversing manoeuvres, turning into parking bays or when shunting in the vicinity of road obstacles near tn the ground, however, a collision may occur at very low speeds.

In order to protect the steerable front axle 2 from consequent damage in the event of such a collision, there is provided in the roller mounting a predetermined breaking 2 point 8 which is arranged inside an interchangeable part 7 in the exemplary embodiment shown in Figures 2 and 3. The roller mounting must be renewed after breaking of the predetermined breaking point. To prevent the predetermined breaking point 8 from breaking directly in the event of slighter collisions, a certain flexibility is created in the roller mounting by making the interchangeable part 7 capable of insertion and clamping by means of a clamping journal 9 in a clamping bore 10 in the mounting flange 22.

For clamping the clamping journal 9 inside the clamping 4 bore 10 there is provided, tangentially to the circumference of the cylindrical mating surface gap 13, a clamping screw 11 by means of which a pair of sieeve-shaped clamping wedges 12 can be pressed against the circumferential surface of the clamping journal 9.

As a result, the plug-in connection can be frictionally clamped so that it can be rotated in the event of an overload, he roller mounting is therefore mounted resiliently kin the case of smaller collisions, only in the event of heavier collisions will the predetermined breaking point 8 react and break after deflecting and checking the impact force. The interchangeable part 7 is secured against removal from the mounting flange 22 by a collar on the end of the clamping journal 9. The corresponding annular recess which receives -the collar forms an axially perpendicular and, again, a short cylindrical mating surface gap. The end flange 23 on the support arm 4 to which the mounting flange 22 is screwed acts against the pressing of the clamping journal 9 into the clamping bor'e in the mounting flange 22.

A deformation sensor 14 is arranged in the region of the mentioned mating surface gap 13, since in all cases the frictionally clamped plug-in connection is rotated before any breaking of the predetermined breaking point 8. The deformation sensor itself is pin-shaped and essentially cylindrical; it is inserted into a bore 15 which transverses the mating surface gap 13. As a result the deformation sensor is in a protected position. Moreover it PI)can be renewed easily and reliably after maladjustment of the roller mounting. The cable 16 which leads to the deformation sensor 14 is guided through a bore inside the end flange 23 and through the interior of the support arm 4, the cable extends into the region of the drivers seat where an appropriate monitoring and display system is arranged, In the exemplary embodiment represented by solid lines in Figures 2 and 3 the bore 15 for receiving the deformation sensor 14 4s arranged axially and passes through the axially perpendicular part of the mating ,O surface gap in the region of the mentioned collar' or the corresponding recess onl the inner side of the mounting flange 22. In addition, thle bore 15 is also in the same radial position as the mating surface gap 13. In the event of a reciprocal pivoting of the clamping Journal 9 inside the clamping bore 10 caused by a collision, the inserted deformation sensor 14 is therefore destroyed immediately and a current path interrupted, which can be indicated within the perception range of the vehicle driver. In 6 another exemplary embodiment indicated by dot-dash lines in Figure 3, the bore 15' for receiving the deformation sensor is arranged radially. The cable 16 runs through an axially directed groove on the outer circumference of the mounting flange 22 and enters the interior of the support arm 4 through an inclined bore. To protect the open side of the bore 15' and also the openings for the cable guide, they can be bonded over by means of a pressure sensitive covering tape 24.

SO The deformation sensor 14 itself is shown in section in an exemplary embodiment in Figure 4, that is, there is provided a tubular breaking piece 18 which is made of material prone to brittle fracture and which is provided on its outer side with an electrically conductive coating The coating can be provided on the entire circumference but it can also be limited to a strip extending in the longitudinal direction of the breaking piece 18. In the end regions of the tubular hollow body 18 the body is shouldered, but the electrically conductive coating is also IO still pre-ant in the region of the shoulder. The bared end of each lead 25 or 25' of a cable 16 extending as far as the interior of the tube is attached to the shouldered ends so as to be electrically conductive. To secure the fastening there is provided at each end a binding 21 which, in its thickness, ccrresponds approximately to the radial dimension of the shoulder so that a smooth cylindrical path of the pin-shaped deformation sensor 14 is not disturbed on the outside. An electrically conductive covering 17 is fitted over the entire arrangement and shrunk tightly on the breaking piece 18 or the coating 20. The covering is tightly sealed in the region of the free end and in the region of the cable 16 so that the deformation sensor 14 is protected against entry of water. Apart from such a protection and an electric insulation of the deformation sensor against its metallic surrounding inside the bore the covering 17 also serves to enable the breaking piece 18 to be inserted into the bore relatively tightly, but still without tilting or without peak stresses. For this purpose 7 the covering should not be too thin or too hard in design.

A shrink-on insulating tubing should provide a suitable covering.

The material for breaking piece 18 which is prone to brittle fracture can be ceramic material, porcelain, glass or phenolformaldehyde resin having a high filler content.

The latter material is known under the registered trade mark Bakelite. The material concerned must in each case be electrically nonconductive. Because of the brittle fracture behaviour of the material complete separation or severing of the breaking piece 18 and, with it, the electric conductor is immediately caused upon displacement of the two parts of the plug-in connection. The electrically conductive coating 20 can be in the form of a conductive lacquer which can be applied for example by means of brushes. Instead, the electrically conductive coating can also be in the form of a metal covering which is deposited by electroplating on the surface of the breaking piece using a conceivable process of application.

AC In this connection there are conceivable processes similar to those normally used to produce tracks on plastic boards for so-called printed circuits. Instead of an electrically conductive coating it is also conceivable to provide on the surface of the breaking piece a wire or strip-shaped thin conductor which runs in a longitudinal groove or a longitudinally extending flat part to protect it against unintentional damage. In addition, it is also conceivable to embed a wire or strip-shaped electric conductor in the mases of the breaking piece. When using wire or stripshaped electric conductors it must be ensured that with the breaking of the breaking piece, the metallic sections are also severed completely in cross-section so that an interruption of the electric conductor takes place immediately. The electric conductors must therefore be very thin in cross-section and, in addition must be applied adhesively to the surface of the breaking piece or embedded without play in the interior of the breaking piece. A further possible development of an electrically conductive coating is to apply a metal coating by vacuum metallizing or apply a carbon coating. The latter is commonly used in the art for low-impedance film resistors.

In the exemplary embodiment according to Figure 5 the breaking piece 18' is constructed in its original form as a cylindrical bar having a solid cross-section which is provided with an electrically conductive coating 20 on the entire outer circumference and also at the ends. An essentially U-shaped path is created for the electrically I)conductive coating 20 by grinding off the electrically conductive coating at an end to which leads 25 or 215' of the cable 16 are to be subsequently connected, and on two oppositely lying narrow strips lying parallel to the surface lines of the cylindrical bar. The two leads 25 or of -the oable 16 can now be connected to -the two sides ,.if this U-shaped conductor and secured thereon by means of an electrically insulating binding 21'. In a modification of' this exemplary embodiment the binding 21' can also extend over the entire length of the breaking piece 18' and Potake over the function of the covering, In the exemplary embodiment of a possible arrangement of the deformation sensor 14 as indicated in Figure 6, the interchangeable part 7' is an integral component with the mounting flange 22', a possible means of rotation between the mounting flange 22' and the cylindrical extension is no provided in this case. In order to enable the deformation sensor 14 to be also still fitted in this exemplary embodiment, the bore 15" for receiving the defo,-rmation sensor 14 extends over and beyond the circumferential Y~1 ~groove 8 which constitutes the predetermined breaking point. When the defor~mation sensor 14 is fitted without play in the bore 16', 'the deformation sensor breaks as soon as the interchangeable part 71 breaks off at the predetermined breaking point 8.

Claims

1. Roller mounting for track-guidable vehicles, including a predetermined breaking and/or predetermined deformation region and comprising a deformation sensor in the form of an electrical conductor, the electrical conductor being electrically insulated from the mounting, which conductor bridges the predetermined breaking or predetermined deformation regions mechanically and which deformatioi sensor breaks when deformed, wherein there is provided in the mounting a bore which traverses the predetermined breaking or predetermined deformation region and into which bore the 1 deformation sensor is insertable, the deformation sensor Scomprising a frangible breaking piece bearing the electrical conductor.

2. Roller mounting according to Claim i, wherein the predetermined deformation region is formed by a plug-in connection comprising a cylindrical pairing of mating cylinders adapted to be clamped together by frictional connection, but which mating cylinders are relatively rotatable in the event of overload, the bore which receives the deformation sensor extending radially or axially across a contiguous surface of the mating cylinders.

3. Roller mounting according to claim I or 2, wherein the breaking piece is provided With a thin walled covering made of soft material for a tight, but tilt-free or peak stress- free retention in the bore.

4. Rollez' mounting according to claim 1, 2 or 3 wherein the breaking piece is made of ceramic material or the like.

Roller mounting according to Claim 1, 2 or 3 wherein the breaking piece is made of glass.

6. Roller mounting according to Claim 1, 2 or 3 wherein the breaking piece is made of phenol-formaldehyde resin having a high filler content. L, ii 1 -i ;ii I: -r i I I de

7. Roller mounting according to any one of Claims 1 to 6 wherein the electrical conductor, which is in the form of fine wire, is embedded in the mass of the breaking piece and provided with outwardly leading connections.

8. Roller mounting according to any one of Claims 1 to 6 wherein the breaking piece is provided on the outside with at least one longitudinal groove or one longitudinally extending flat part into which the electrical conductor is adhesively embedded or to which the electrical conductor is attached.

9. Roller mounting according to any one of Claims 1 to 6 wherein the electrical conductor comprises on, at least part of, the outer surface of, an electrically conductive coating so as to extend in the longitudinal direction of the breaking piece.

Roller mounting according to Claim 9, wherein the coating consists of a conductive lacquer.

11. Roller mounting according to Claim 9, wherein the coating is a metal covering which can be applied by electrochemical or electroplzatifg means.

12. Roller mounting according to any one of Claims 1 to 11, wherein the breaking piece is in the form of a small tube, the S connections of the conductor being connected to the leads of a cable which extends as far as the interior of the small tube,

13. Roller mounting according to any one of claims 1 tco 12, wherein a binding for the mechanical and electrical con;ection of the leads of a cable to the conductor is fitted in the region of at least one end of the breaking piece and that in the area of the binding the breaking piece is reduced in diameter by at least the thickness of the binding. 11

14. Roller mounting according to any one of Claims 3 to 13, wherein the covering is designed to be electrically insulating. Roller mounting substantially as hereinbefore described with reference to and as illustrated in Figures 2 to 6 of the accompanying drawings. DATED this FOURTEENTH day of NOVEMBER 1990 Daimler-Benz AG 'I Patent Attorneys for the Applicant SPRUSON FERGUSON ii ,4