US3146977A - Electric heaters for railway permanent way systems - Google Patents

Description

, p 1964 A. COATES ETAL ELECTRIC HEATERS FOR RAIL-WAY PERMANENT WAY SYSTEMS Fileci' Oct. 8, 1962 v 2 Sheets-Sheet 1 INVENTQRS A. Coai'es 6. B. Russ ATTQZNELY p 1, 1964 A. COATES ETAL 3,146,977

ELECTRIC HEATERS FOR RAILWAY PERMANENT WAY SYSTEMS Filed Oct. 8, 1962 2 Sheets-Sheet 2 .h I I I E M L' K w 3 2 j 9 INVENTORS Acoates GHRusse/l BY H, Bi-r-cl-nenhough MJZ/JMM United States Patent M ELECTRIC HEATERS FOR RAILWAY PERMA- NENT WAY SYSTEMS Arthur Coates, Leeds, and Gordon B. Russell, Scholes, near Leeds, England, and Herbert Birchenhough, 17 Tennison Ave., Borehamwood, Hertfordshire, England; said Coates and said Russell assignors to Geo Bray & Co. Limited, Leeds, England Filed Oct. 8, 1962, Ser. No. 228,984 4 Claims. (Cl. 246-428) This invention relates to electric heaters for railway permanent way systems, the purpose of such heaters being to prevent ice and snow accumulation in the vicinity of moving parts which may in turn prevent operation of mechanically or manually operated switch rails.

It is already known to clamp electric heaters or electrically heated oil pipe circuits to a rail of a permanent way, but the mechanical clamping means used have involved structural modification to the rail on site. It is accordingly more usual to apply salt or grease by hand to those parts at which freezing is to be avoided but considerable labouris involved in the adoption of this method and in addition it is found that undesirable corrosion of the metal parts results from the use of salt.

The object of the present invention is to provide an improved form of heater eliminating completely any reduction in mechanical strength of the parts to be heated and at the same time effectively preventing excessive ice and snow build up on the points or other movable parts and thereby to reduce the possibility of accidents or traffic delays which may otherwise result from inoperation of railway points. The method of use affords simplicity of installation normally without disturbance either mechanical or physical to the surroundingrail point parts.

According to the present invention an electric heating assembly is constructed for attachment to a slide chair of a railway permanent way in situ, the assembly including a heater element the disposition of which is such that heat is transmitted by both conduction and radiation to the slide chair and parts mounted thereon.

In a particular form of heating assembly according to the invention, a sheathed wire tubular electric heating element of generally hairpin form carries near the end of each limb clamping means constructed to engage a rail or other member to be heated and the extremities of the heating element each terminates in a watertight terminal box.

One form of heater assembly embodying the invention and constructed and arranged to be mounted on a railway slide chair will now be described in greater detail by'way of example with reference to the accompanying drawings in which:

FIGURE 1 is a side elevation of such an assembly mounted on a slide chair, some details being shown in section;

FIGURE 2 is a plan view;

FIGURE 3 is an end elevation as seen from the left of FIGURE 1;

FIGURE 4 is a front elevation of a component which will be referred to as a fixing claw; and

FIGURE 5 is a cross-sectional view taken on the line A--A in FIGURE 2 to an enlarged scale.

Referring to the drawings, a slide chair indicated generally at 1 to which the heater assembly is applied is of conventional form consisting of a heavy rectangular base plate 2 with holes 3 at the corners for the reception of bolts, not shown, which secure the slide to a sleeper, not shown. The slide is located on the sleeper so that a fixed stock rail 4 crosses it transversely near one end, the top horizontal surface 5 of the plate providing the slide area for a switched rail, not shown. The slide M 3,146,977 Patented Sept. 1, 1964 area is raised with respect to the base plate and is defined by a shoulder 6 which, at the end remote from the fixed stock rail is semi-circular in form.

The heating element 7 is of the sheathed wire tubular type of circular cross-section approximately 1 of an inch in diameter and containing a centrally embedded resistor in a refractory insulating cement. The sheathing is of heat resisting material, is completely impervious to moisture, and in the particular example being described is formed with diametrically opposite longitudinal ribs 8 (FIGURES 2 and 5). An appropriate length of such element is bent into broad generally hairpin formation and the bent end is laid around the vicinity of the semicircular portion of the shoulder 6 defining the slide area of the slide chair. The limbs of the hairpin extend along each side of the shoulder in close contact therewith up to a point at which each limb becomes slightly spaced apart from the slide chair and is held by a distance fin 9.

The two fins 9 serve to maintain the heating element in position below the horizontal working surface of the slide chair and as will be seen from FIGURE 5 each fin is in the form of a bar with a longitudinally recessed edge made large enough to accommodate the element. Between the points at which the element loses contact with the shoulder 6 of the slide chair and the point of entry 'into the recessed fins, the element is twisted through 45 about its longitudinal axis so that the ribs 8 will be positioned as shown in FIGURE 5. A portion 8a of a rib in the twisted position is shown in FIGURE 2. Preferably the limbs of the element are secured in their respective fin recesses by a silver solder or other means of jointing.

The end of each limb passes freely through a hollow bolt 10 which carries a claw like clamp 11, the claw portion of which is shaped to engage the lower outer flange 12 of the fixed stock rail 4. The extremity 13 of each limb of the element then freely passes into a metal terminal box 14 to which the sheath of the element is brazed as at 15 to form a watertight connection. Each terminal box is cylindrical in form and is made completely moisture proof utilising an oil and moisture tight sealing ring 16 and an insulating lining sleeve 17 which surrounds the connection between the core cable of the heating. element and the end of a supply conductor, not shown. The supply conductor passes through a cap 18 on a screw threaded extension 19 of a closure 20 for the terminal box 14 and a flange 21 of the closure 20 serves to clamp the sealing ring 16.

The head 22 of the sleeve bolt 10 abuts the end of the terminal box 14 and a nut 23 on the sleeve abuts the claw clamp 11. Thus, when the sleeve bolt head and the nut are tightened in opposition, the element is clamped in contact with the slide chair and the claw clamp firmly grips the stock rail 4 so holding the assembly securely in position. A locking nut 24 is provided.

In an alternative construction, in order to ensure that the bent end of the element shall not lift away from the slide chair, a strip clamp may be used to hold it down. Thus one end of a horizontally disposed Z-shaped metal strip may be bent over and brazed to the element and the other end secured by a screw bolt to a sleeper.

Although reference has been made to the use of an element having longitudinal ribs, it will be understood that any appropriate form of heating element may alternatively be used and changes in detailed construction may be made.

It will be seen that the heating assembly described lends itself to attachment to a slide chair of a railway permanent way in situ without requiring alteration to or modification, disturbance or reduction in mechanical strength of the slide chair or permanent Way.

We claim:

1. An electric heating assembly constructed for attachment to the slide chair of a railway permanent Way in situ, said heating assembly comprising a heating element of the sheathed wire tubular type and of'hairpin form, clamping means forclarnping-said heating element in heat conductive relation with said slide chair and a fixed track rail on said slide chair, the assembly farther comprising a watertight terminal box for the extremity of each limb of said heating element, said clamping means consisting of a-pair of clamp members disposed one on each limb'of said heating element and engaging said fixed track rail, each of said clamp members being in the form of atclaw the jaws of which engageithe flange of said fixed track rail, a pair of hollow bolts each of which has one of said claws slidably mounted thereon, said bolts each having a screw-threaded shank and a head and through each of which one limb of said heating element passes, the head of each bolt being disposed in abutting relation-with the terminal box forisaid one limb of said heating-element and each bolt. having thereon a nut which provides an abutment for the claw "slidably mounted thereon.

2. An electric heating assembly according to claim 1 in whichrneans are provided for retaining the heating element below the level of the horizontalslide face of said slide chair.

'3. An electric heating assembly constructed for attachment to the slide chair of a railway permanent way in situ, said heating assembly comprising a length of heating element of the sheathed wire tubular type bent to conform with the shape of a portion of the slide chair, clamping means for clamping said heating element in heat conductive relation with said slide chair and a fixed track rail on said slide chair, the assembly further comprising a watertight terminal box for the extremity of each limb of said heating element, said clamping means consisting of a pair of clamp members disposed one on each limb of said heating element and engaging said fixed track rail, each of said clamp members being in the form of a claw the jaws of which engage the flange of said fixed track rail, a pair of hollow bolts each of which has one 1 References Cited inthe file of this patent UNITED STATES. PATENTS 1,329,007 Paige Jan. 27, 1920 1,474,161 Packer Nov. 13, 1923 1,897,218 Scholz- Feb. 14, 1933 1,957,977 Packer May 8, 1934

Claims (1)

1. AN ELECTRIC HEATING ASSEMBLY CONSTRUCTED FOR ATTACHMENT TO THE SLIDE CHAIR OF A RAILWAY PERMANENT WAY IN SITU, SAID HEATING ASSEMBLY COMPRISING A HEATING ELEMENT OF THE SHEATHED WIRE TUBULAR TYPE AND OF HAIRPIN FORM, CLAMPING MEANS FOR CLAMPING SAID HEATING ELEMENT IN HEAT CONDUCTIVE RELATION WITH SAID SLIDE CHAIR AND A FIXED TRACK RAIL ON SAID SLIDE CHAIR, THE ASSEMBLY FURTHER COMPRISING A WATERTIGHT TERMINAL BOX FOR THE EXTREMITY OF EACH LIMB OF SAID HEATING ELEMENT, SAID CLAMPING MEANS CONSISTING OF A PAIR OF CLAMP MEMBERS DISPOSED ONE ON EACH LIMB OF SAID HEATING ELEMENT AND ENGAGING SAID FIXED TRACK RAIL, EACH OF SAID CLAMP MEMBERS BEING IN THE FORM

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