GB2110327A - Brake shoe assembly - Google Patents
Brake shoe assembly Download PDFInfo
- Publication number
- GB2110327A GB2110327A GB08228262A GB8228262A GB2110327A GB 2110327 A GB2110327 A GB 2110327A GB 08228262 A GB08228262 A GB 08228262A GB 8228262 A GB8228262 A GB 8228262A GB 2110327 A GB2110327 A GB 2110327A
- Authority
- GB
- United Kingdom
- Prior art keywords
- assembly
- brake shoe
- shoe
- tooth
- teeth
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 claims abstract description 9
- 239000000463 material Substances 0.000 claims abstract description 4
- 229910000831 Steel Inorganic materials 0.000 claims description 2
- 238000005219 brazing Methods 0.000 claims description 2
- 238000005266 casting Methods 0.000 claims description 2
- 238000003754 machining Methods 0.000 claims description 2
- 239000010959 steel Substances 0.000 claims description 2
- 238000003466 welding Methods 0.000 claims description 2
- 229910001209 Low-carbon steel Inorganic materials 0.000 abstract description 2
- 239000002184 metal Substances 0.000 abstract description 2
- 229910052751 metal Inorganic materials 0.000 abstract description 2
- 230000015572 biosynthetic process Effects 0.000 abstract 1
- 229910000906 Bronze Inorganic materials 0.000 description 1
- 229910001018 Cast iron Inorganic materials 0.000 description 1
- 239000010974 bronze Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- KUNSUQLRTQLHQQ-UHFFFAOYSA-N copper tin Chemical compound [Cu].[Sn] KUNSUQLRTQLHQQ-UHFFFAOYSA-N 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 239000002783 friction material Substances 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B61—RAILWAYS
- B61H—BRAKES OR OTHER RETARDING DEVICES SPECIALLY ADAPTED FOR RAIL VEHICLES; ARRANGEMENT OR DISPOSITION THEREOF IN RAIL VEHICLES
- B61H7/00—Brakes with braking members co-operating with the track
- B61H7/02—Scotch blocks, skids, or like track-engaging shoes
- B61H7/04—Scotch blocks, skids, or like track-engaging shoes attached to railway vehicles
- B61H7/06—Skids
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D69/00—Friction linings; Attachment thereof; Selection of coacting friction substances or surfaces
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D69/00—Friction linings; Attachment thereof; Selection of coacting friction substances or surfaces
- F16D69/02—Composition of linings ; Methods of manufacturing
- F16D69/027—Compositions based on metals or inorganic oxides
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D69/00—Friction linings; Attachment thereof; Selection of coacting friction substances or surfaces
- F16D2069/004—Profiled friction surfaces, e.g. grooves, dimples
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Braking Arrangements (AREA)
Abstract
A brake shoe assembly 1 for a rail vehicle, comprises a backing plate 2 and at least one brake shoe 3 carried thereby, the or each shoe 3 having a multiplicity of teeth 13 formed of or incorporating hard material (e.g. tungsten carbide), the teeth 13 projecting from their shoe 3 and being adapted, in the braking condition, to engage an adjacent railway rail, each tooth 13 being so positioned that no tooth 13 on the shoe 3 is located in front of, or behind another tooth 13 on the shoe 3, with respect to the direction of braking. The avoidance of tooth alignment ensures that each tooth has a braking effect rather than following in a groove ploughed by another tooth. As shown, three shoes 3 (of mild steel) have circular mounting projections (9) fitting holes (7) in plate 2 and secured by weld metal (10). Details of the formation of nine teeth 13 on each shoe are given. <IMAGE>
Description
SPECIFICATION
Brake shoe assembly
This invention relates to a brake shoe assembly for a rail vehicle and in particular for a rail vehicle operating in wet or dirty conditions e.g. in an underground mine.
Conventionally, brake shoes are of friction material e.g. cast iron, Ferodo (Trade Mark), sintered bronze, but in the wet and/or slimy conditions frequently encountered underground, and having regard to the gradients frequently encountered underground, friction brakes are usually operable with a much reduced braking effect, if in fact they are capable of producing any braking effect whatsoever, on the vehicle to which they are fitted.
According to the present invention, there is provided a brake shoe assembly for a rail vehicle comprising a backing plate and at least one brake shoe carried thereby, the or each shoe having a multiplicity of teeth formed of or incorporating hard material, the teeth projecting from their shoe and being adapted, in the braking condition, to engage an adjacent railway rail, and each tooth being so positioned that no tooth is located in front of, or behind, another tooth, with respect to the direction of braking.
Thus, when a brake shoe assembly in accordance with the invention is put into the braking condition, the projecting teeth of the shoe penetrate any surface slime, water etc. on the adjacent rail, while the avoidance of tooth alignment ensures that each tooth is capable of having a braking effect rather than following in a groove ploughed by a preceding tooth, and the vehicle to which the shoe assembly is attached is braked by the projecting teeth causing in fact plastic flow of the rail head material around the teeth, and in particular the tips thereof. Under normal conditions and loads this results in the rail heads becoming grooved to a depth of approximately 0.010 in, but such small grooves are generally rolled out again by passage of the rail wheels.Tests have shown that the brake shoe assembly in accordance with the invention produces an apparent coefficient of friction of 0.375 u, while the tips of the teeth are selfcleaning and are readily capable of negotiating joints in the railway rails.
Each tooth preferably has a negative rake angle which minimises any cutting effect on the rail whilst improving tooth life. Conveniently, the teeth incorporate tungsten carbide. In detail, the or each brake shoe may be produced in steel, by casting or by machining from bar stock, with a slot subsequently milled into the shoe to receive a strip of tungsten carbide which is located by brazing.
The teeth may be produced by grinding, before or after insertion of the strip(s) of tungsten carbide. In a preferred embodiment, the or each brake shoe has a square, tooth carrying head provided with nine teeth and three, spaced apart, parallel milled slots each housing a strip of tungsten carbide of any suitable cross-section. It is also preferred for the backing plate to be elongate and to be
apertured at various locations to receive mounting
projections of each brake shoe. The apertures may
for instance be circular holes, in which case the
mounting projections are of corresponding circular
section. The or each brake shoe may be secured to
its backing plate by welding. An underside of the
square tooth-carrying head of the or each brake
shoe may abut against an adjacent face of the
backing plate.Non-alignment of teeth may be
effected by angling the strip(s) or the brake shoe
with respect to the direction of braking. Thus for a
nine tooth, square headed shoe, a side edge of the
shoe may be located at 1 50 to 300 to the
longitudinal axis of the body member. It is also
preferred for the negative rake angle to be of the
order of 450 which gives a desired self-cleaning effect and which also provides maximum strength
at the tips of the teeth thereby precluding chipping of the teeth when the tips thereof negotiate a rail joint. In one embodiment, three brake shoes are
carried by each backing plate.These may be
arranged such that a central brake shoe is located on the longitudinal axis of the backing plate, to
provide the normal braking effect while the other
brake shoes are located above and below this axis, one forwardly and one rearwardly of the central brake shoe, for braking when the associated vehicle negotiates a curve in the railway rails.
The invention will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a front view of a brake shoe assembly in accordance with the invention;
Figure 2 is a side view of Figure 1;
Figure 3 is a side elevation on a brake shoe of
Figures 1 and 2; and
Figure 4 is a view in the direction of arrow B of
Figure 3.
In the drawings, a brake shoe assembly 1 comprises basically a backing plate 2 and three brake shoes 3.
As can be seen in Figure 3, the backing plate 2 is elongate, having a longitudinal axis 4, parallel long sides 5 and ends 6. Three circular holes are provided in the backing plate 2, one hole 7 being a central hole located on the longitudinal axis 4 midway between the ends 6, while the other two holes 7 are located one to each side of the longitudinal axis 4, one nearer to each end 6 than the central hole. The backing plate 2 is also provided with six holes 8 by which it is mounted, using countersunk screws, on a brake actuating mechanism (not shown).
As can be seen in Figures 5 and 6, each brake shoe 3, e.g. of mild steel, comprises a circular section mounting projection 9 of diameter to fit a hole 7 and is secured in position on the backing plate by weld metal 10 (see Figure 2). Each brake shoe 3 also comprises a square head 11 into which are milled three slots each to receive a strip 1 2 of tungsten carbide brazed into position, each head 11 being ground to form nine teeth 13 with the tungsten carbide at their tips and having a 450 negative rake angle. In order that no tooth 13 shall be in front of or behind, another tooth, with respect to the direction of braking, and hence so that all nine teeth 1 3 shall have a braking effect, then as shown in Figure 1, the brake shoes 3 are welded to the backing plate 2 with a 200 angle between an adjacent side of the square head 11 and a long side 5 of the backing plate 2, or conversely between any strip 20 and a line transverse to the direction of braking i.e.
transverse to the longitudinal axis of the backing plate 2.
Claims (17)
1. A brake shoe assembly for a rail vehicle comprises a backing plate and at least one brake shoe carried thereby, the or each shoe having a multiplicity of teeth formed of or incorporating hard material, the teeth projecting from their shoe and being adapted, in the braking condition, to engage an adjacent railway rail, and each tooth being so positioned that no tooth is located in front of, or behind, another tooth, with respect to the direction of braking.
2. An assembly as claimed in Claim 1 , wherein each tooth has a negative rake angle.
3. An assembly as claimed in Claim 1 or
Claim 2, wherein the teeth incorporate tungsten carbide.
4. An assembly as claimed in any preceding
Claim, wherein the or each brake shoe is of steel.
5. An assembly as claimed in any preceding
Claim, wherein the or each brake shoe is produced by casting or machining from bar stock.
6. An assembly as claimed in Claim 4 and any
Claim appendant thereto, wherein the teeth are produced by grinding.
7. An assembly as claimed in any preceding
Claim, wherein the or each brake shoe has a slot to receive a strip of tungsten carbide which is located by brazing.
8. An assembly as claimed in Claim 7, wherein the or each brake shoe has a square tooth-carrying head provided with nine teeth and three, spaced apart, parallel milled slots.
9. An assembly as claimed in any preceding
Claim, wherein the backing plate is elongate.
10. An assembly as claimed in Claim 9, wherein the backing plate is apertured at various locations to receive mounting projections of the or each brake shoe.
1 An assembly as claimed in Claim 10, wherein the apertures are circular holes,;n which case the mounting projections are of corresponding circular section.
12. An assembly as claimed in Claim 10 or
Claim 1 wherein the or each brake shoe is secured to its backing plate by welding.
13. An assembly as claimed in Claim 8 and any
Claim appendant thereto, wherein an underside of the square tooth-carrying head of the or each brake shoe, abuts against an adjacent face of the backing plate.
14. An assembly as claimed in Claim 7, and any
Claim appendant thereto, wherein the strip(s) or the or each shoe is angled with respect to the direction of braking.
1 5. An assembly as claimed in Claim 14, wherein the angling of the strip(s) is at 1 50--300 to a line transverse to the direction of braking.
1 6. An assembly as claimed in any preceding
Claim, wherein the teeth rake angle is of the order of 450.
17. An assembly as claimed in any preceding
Claim, wherein three brake shoes are carried by each backing plate.
1 8. An assembly as claimed in Claim 15, wherein a central brake shoe is located on the longitudinal axis of the backing plate, while the other brake shoes are located above and below this axis, one forwardly and one rearwardly of the central brake shoe.
1 9. A brake shoe assembly for a rail vehicle, substantially as hereinbefore described with reference to the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08228262A GB2110327B (en) | 1981-11-21 | 1982-10-04 | Brake shoe assembley |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8135155 | 1981-11-21 | ||
| GB08228262A GB2110327B (en) | 1981-11-21 | 1982-10-04 | Brake shoe assembley |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2110327A true GB2110327A (en) | 1983-06-15 |
| GB2110327B GB2110327B (en) | 1984-11-21 |
Family
ID=26281342
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08228262A Expired GB2110327B (en) | 1981-11-21 | 1982-10-04 | Brake shoe assembley |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2110327B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0621415A1 (en) * | 1993-04-22 | 1994-10-26 | AlliedSignal Bremsbelag GmbH | Lining for disc brakes, particularly for high speed trains |
| WO2004003397A2 (en) * | 2002-07-01 | 2004-01-08 | Marcelo Laterza Lopes | Disposition on disk brake pads |
-
1982
- 1982-10-04 GB GB08228262A patent/GB2110327B/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0621415A1 (en) * | 1993-04-22 | 1994-10-26 | AlliedSignal Bremsbelag GmbH | Lining for disc brakes, particularly for high speed trains |
| WO2004003397A2 (en) * | 2002-07-01 | 2004-01-08 | Marcelo Laterza Lopes | Disposition on disk brake pads |
| WO2004003397A3 (en) * | 2002-07-01 | 2004-04-08 | Marcelo Laterza Lopes | Disposition on disk brake pads |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2110327B (en) | 1984-11-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4501079A (en) | Two piece cutting edge construction | |
| CA1152128A (en) | Excavating tooth assembly | |
| US6854527B2 (en) | Fracture resistant carbide snowplow and grader blades | |
| US4625439A (en) | Excavating tooth retaining means | |
| US4162770A (en) | Tooth breaker members | |
| US4752081A (en) | Fifth wheel bearing plate cover with inboard protective skip plates | |
| CA2605513C (en) | Two piece draft gear housing having an integral yoke | |
| KR20130052561A (en) | Cutting tool | |
| US20200222999A1 (en) | Rotating cutting assembly and cutting tooth for a rotating cutting assembly | |
| CS253577B2 (en) | Single-tool reamer | |
| GB2147562A (en) | Locking device | |
| GB2110327A (en) | Brake shoe assembly | |
| US20070119665A1 (en) | Outer pad abutment design for frame type calipers | |
| DK1175531T3 (en) | Ice scraper with non-rotatable tools with shielded cutting inserts | |
| GB2074631A (en) | Means for holding cutter bits | |
| EP1201386A3 (en) | Masonry cutting members having wear indicators | |
| US2109871A (en) | Brake block with interchangeable brake surface | |
| GB2176520A (en) | Tool unit for mechanical shovels, front loaders, grabs or the like | |
| KR200165639Y1 (en) | Pad changing tool of abs disk brake for a car | |
| US4010526A (en) | Cut-off tool | |
| JPS59161225A (en) | Reamer | |
| DE202013104616U1 (en) | Assembly of a brake pad with wear indicator | |
| JPS6151175B2 (en) | ||
| US1605861A (en) | Detachable scarifier tooth | |
| US147856A (en) | Improvement in the construction of car-brakes |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |