Classifications

• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01B—PERMANENT WAY; PERMANENT-WAY TOOLS; MACHINES FOR MAKING RAILWAYS OF ALL KINDS
  • E01B9/00—Fastening rails on sleepers, or the like
  • E01B9/02—Fastening rails, tie-plates, or chairs directly on sleepers or foundations; Means therefor
  • E01B9/28—Fastening on wooden or concrete sleepers or on masonry with clamp members
  • E01B9/30—Fastening on wooden or concrete sleepers or on masonry with clamp members by resilient steel clips
  • E01B9/306—Fastening on wooden or concrete sleepers or on masonry with clamp members by resilient steel clips the clip being a shaped plate
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01B—PERMANENT WAY; PERMANENT-WAY TOOLS; MACHINES FOR MAKING RAILWAYS OF ALL KINDS
  • E01B9/00—Fastening rails on sleepers, or the like
  • E01B9/02—Fastening rails, tie-plates, or chairs directly on sleepers or foundations; Means therefor
  • E01B9/28—Fastening on wooden or concrete sleepers or on masonry with clamp members
  • E01B9/30—Fastening on wooden or concrete sleepers or on masonry with clamp members by resilient steel clips
  • E01B9/303—Fastening on wooden or concrete sleepers or on masonry with clamp members by resilient steel clips the clip being a shaped bar

Definitions

• ELASTIC RAIL CLAMPS This invention relates to elastic rail clamps, used in rail fastening systems, of the kind which are applied at right angles to the rail.
• Elastic rail clamps of this kind are described in U.S. Patents 3,067,947 (Deenik) and 4,313,563 (Young) .
• both these clamps are designed for use with a custom made shoulder into which the base of the elastic clamp fits .
• Both rail clamps have toe portions which lie on the rail flange and the outer edges of these abut the support shoulder to prevent them sliding off the rail flange.
• the "Young" clip is used with a shoulder as described in U.S. Patent 4,688,719 which has a shoulder with a tapered slot leading to the gate which acts to compress the arms together as the clamp is driven into place with the toe portion on the rail flange.
• a common rail plate used in Europe is called a K plate which includes a pair of parallel ribs adjacent and parallel to the rail flange and slots in the ribs at right angles to the rail flange. These slots are not tapered and thus the toes of the rail clamps need to be compressed to pass through the slot if the toes are to be prevented from sliding off the rail flange.
• the Deenik clip can only be applied to the K plate with a tool which compresses the arms of the toe portion to pass through the gate in the shoulder. With older rail tracks the variation in height between rail plate slot and rail flange can vary greatly in stationary and dynamic modes and thus maximum clamp deflection between the base of the toe portions is needed.
• an elastic rail clamp comprising a base portion and a toe portion wherein the toe portion lies on the rail flange and the base portion is adapted to be secured to a rail plate or rail tie, said clamp comprising a pair of substantially parallel members bent into a D configuration such that one end of said pair of members forms the toe of the clamp and the other end forms the base of said clamp, the pair of members being joined together between the curved portion of the members adjacent the base portion.
• the base comprises two free arms extending toward the rail.
• the advantage which arises from the provision of free ends for the base is greater deflection for the clamp which means it can fit into a wider range of rail track environments.
• the provision of the junction between the members at a position at the rear of the clamp just above the base means that there is a large non-critical area as a target for hitting the clamp with a sledge hammer to drive the clamp into position.
• this is the portion of the clamp most likely to receive high sideward forces from ballast pressure during ballast regulation and the fact that the two members of the clamp are joined at this position minimises the possibility of clamp damage.
• joining the members together at the rear of the clamp provides a means to maximize clamp deflection for a given toe load while retaining sufficient strength to minimise damage during application of the clamp and during track working processes such as ballast regulation.
• the legs of the base are tapered toward their ends.
• the clamps may be formed from rod or bar steel .
• the clamps are formed from 40mm wide bar stock in a forging and shaping operation.
• the base needs to be of a wider dimension than the width of the stock bar.
• this invention provides a rail clamp for fastening a rail to an underlying rail plate or rail tie
• rail clamp comprises a pair of substantially parallel members folded into a D configuration so as to have a front portion adapted to seat on a flange of the rail, which front portion is formed by respective free ends of the substantially parallel members, and a base portion adapted to seat in a slot in the rail plate or rail tie, wherein the parts of the substantially parallel members between the base portion and the front portion of the clamp are tapered in external dimensions towards the front portion, and the free ends of the substantially parallel members are turned back toward a rear portion of the clamp and project outwardly so as to abut a portion of the rail plate or rail tie when the clamp is in use, thereby to prevent the rail clamp sliding off the rail flange.
• This tapering of the toe portion of the clamp means that as the clamp enters the slot of the rail plate or clamp support shoulder the arms of the clamp and the outwardly projecting ends of the toe portion are compressed toward each other to pass through the slot and once the toe portion is on the rail flange the external width of the outwardly projecting toe portions is greater than the slot width and the rail clamp is locked onto the rail flange.
• Figures IA, IB and IC show respective plan and sectional views of a K plate rail plate for use with embodiments of the present invention
• Figures 2A, 2B and 2C show respective front elevational, side elevational and underneath plan views of a rail clamp embodying the present invention
• Figures 3A and 3B show views of first and second blanks formed during the process of shaping such a rail clamp from bar stock steel.
• Figs . 4a to 4e show stages of a conventional manufacturing method for a prior art clip
• Figs. 5a to 5d show stages of a new manufacturing method for a prior art clip; and Figs. 6a and 6b show some stages of a new manufacturing method for a clip embodying the present invention.
• a K plate 1 is shaped to hold a rail (not shown) between the ribs 3 whic:. abut the rail flange.
• Slots 4 shown in cross section in Figure lc are located on opposite sides of the rail in ribs 3 and are of constant cross section perpendicular to the rail.
• the rail clamp base 11 (Fig. 2) fits in the slot 4 and the rearwardly facing ends 18 of the toe 16 of the clamp 10 abut the sides 5 of the slots 4.
• the rail clamp 10 shown in Figures 2A, 2B, 2C comprise base legs 11, rear web 13, legs 14, toe 16 and toe ends 18.
• the rail clamp 10 is formed from bar stock by hot blanking the bar stock into the form shown in Figure 3A.
• the blanking forms a pair of substantially parallel members 19 forming the base legs 11 and legs 14 in tapered form extending from the web 13.
• the hot blank is then coined along edges 12 of the web and legs 11 and edges 15 of the web 13 and legs 14.
• the outer edges 17 of the clamps are also coined. Coining reduces the likelihood of stress fractures.
• the next step in forming the rail clamp is as shown in Figure 3B to form the legs 14 into a curved form in the two dimensional blank which will produce the tapered toe portion of the final three dimensional form as shown in Figure 2A.
• the narrowest width across the legs 14 in the Figure 3B blank corresponds to the frontmost portion of the toe portion 16 of the clamp 10.
• the second step also widens the base legs 11 to a size which will fit and secure the rail clamp 10 in the slot of the rail plate 1.
• the rail clamp 10 has the web 13 joining the two arms 19 of the clamp at the rear 13 of the clamp 10 which can function to receive the force to push the clamp 10 onto the rail flange.
• the toe portion 16 is narrow enough to seat within the upper portion of the slot 4 and pass between the edges 5 and onto the rail flange.
• the ends 18 of the legs 14 snap apart and prevent removal of the clamp 10 and keep the toe portion 18 on the rail flange.
• the long tapered legs of the toe and base portions 11, 14 of the clamp 10 mean that the deflection range of the clamp 10 is greater than possible in prior art constructions.
• the present rail clamp is able to be used in a wider range of track situations without a custom made shoulder clamp or a special applicator tool.
• Figs. 4a to 4e show steps in a conventional manufacturing method for a prior art clip of the type described earlier and disclosed in US-4,313, 563.
• the spring clip is manufactured from a blank of steel 100, rectangular in shape, with a large 'V shape cut out to form the two principal legs of the fastening.
• Fig. 5a shows a round metal bar 110 to be used to form a clip as shown in Figs. 2a to 2c.
• the round bar is not forged to produce the shape shown in Fig. 5b.
• Figs. 5c and 5d show cross sections through the line Vc-Vc and Vd-Vd in Fig. 5b respectively.
• a straight piece of round bar is formed into a 'U' shape as shown in Fig. 5a and then subsequently forged into a pair of closed dies to form a final blank shape.
• the die shape is such that the excess material overflows about the centre line of the blank and all the external edges of the blank have an appropriate radii .
• the rounded edge significantly reduces the risk of crack propagation during the service life of the clip and removes the necessity to "coin” the edges as required when manufacturing using strip steel.
• a final “clipping" operation to remove excess material is required before the blank is hot formed into the final clip shape.
• the method of manufacturing forging dies permits them to be manufactured such that the resulting product has no sharp edges, all being rounded appropriately.
• Figs . 6a and 6b show steps in forming a metal bar 120 into a blank as shown in Figs. 3a and 3b.
• the final blank shape (Fig. 6b) is forged from a length of round bar such as that shown in Fig. 6a, the dies being manufactured so that all edges have a chamfer or radius giving edge conditions for optimum fatigue life.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Railway Tracks (AREA)
• Clamps And Clips (AREA)
• Body Structure For Vehicles (AREA)
• Springs (AREA)

Priority Applications (21)

Applications Claiming Priority (1)

Publications (2)

Family

ID=10786744

Family Applications (1)

Country Status (9)

Cited By (3)

Families Citing this family (1)

Citations (8)

• 1996
  • 1996-02-13 MD MD99-0080A patent/MD990080A/ro unknown
  • 1996-02-13 WO PCT/GB1996/000319 patent/WO1997030224A1/en active Application Filing
  • 1996-02-13 EA EA199700311A patent/EA000137B1/ru not_active IP Right Cessation
  • 1996-02-13 SK SK1368-97A patent/SK136897A3/sk unknown
  • 1996-02-13 RO RO97-01877A patent/RO118315B1/ro unknown
  • 1996-02-13 AU AU46703/96A patent/AU4670396A/en not_active Abandoned
  • 1996-02-13 EE EE9700257A patent/EE9700257A/xx unknown
• 1997
  • 1997-02-11 HU HU9900907A patent/HUP9900907A2/hu unknown
  • 1997-10-10 BG BG101957A patent/BG101957A/xx unknown

Patent Citations (8)

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