US2035445A - Third rail securing device - Google Patents

Description

March 31 1936. w, A K 2,035,445'

THIRD RAIL SECURING DEVICE Filed Nov; 27, 1954 2 Sheets-Sheet l PIC-3.2.

FIG.

/ INVENTOR.

WILLIAM C. BAN KS By W w-a m ATTORNEY.

March 31, 1936. w c. BANKS THIRD RAIL SECURING DEVICE File d Nov. 27, 1934 5 FIG.4-..

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INVENTOR.

WILLIAM C. BANKS 03:; r Maw ATTORNEY.

Patented Mar. 31, 1936 STATES PATENT OFFICE THIRD RAIL SECURING DEVICE Application November 27, 1934, Serial No. 754,973

14 Claims.

This invention relates to the stationary conductor which supplies electric power of electrically operated train systems, such as subway trains or trains operating on elevated tracks, to the control car of the running train, and which conductor is known as the live or third, or power rail.

Ordinarily a current length of power rail extends parallel to and along the track rails of the system and is spaced from the ground while supported by suitable insulators at suitable intervals. ihe power rail is also arranged and spaced relative to the train so that a resiliently mounted contact shoe may reach from the control car into resilient sliding engagement with the rail or conductor from which to draw its power.

It is desirable to have the power rail connected as safely as possible with the supporting insulator bodies in some suitable way as is usually done by means of clamping devices, the insulators in turn being suitably supported from and fixed to a base which is in turn fixed with respect to the ground. It is a problem then to so interconnect these relatively heterogeneous elements which constitute the support, that they will not loosen, weaken, or otherwise gradually succumband eventually break under the elfect of constantly repeated vibratory and other strains, shocks, or stresses, which they receive through impulses from. the speeding train. In other words, this involves the difiiculty that an electric insulator of commonly available material such as poreclain although possessing a required electric strength against the potential of the earth, has no appreciable toughness or mechanical or tensile strength. Due to its brittle character the molecular coherence of the material may sooner or later give way in a possible break, when subjected to the ever recurrent impact of complicated or compound stresses.

Expressing the difficulty in still other words, the supporting insulator structure for the power rail includes substantially three structural connections, such as between the rail and an insulator body, between the insulator body and an in sulator baseplate, and between the insulator base and the rail tie, each such connection presenting a problem in the transmission and sustenance of certain stresses.

A vibratory system can be said to exist which includes as elements the moving or speeding train, the track rails, the sleepers or rail cross ties, the ground or foundation, and the power rail and its supporting members. Vibrations,

shocks, or stresses are induced by the rolling train and they may reach the power rail and its supporting members via the ground; or else they are transmitted more directly for instance through the rail cross ties, since the insulator base or foot or socket may be directly bolted onto the cross tie which may be of the wooden impregnated type.

Still other impulses affecting the power rail and its supporting structure may come from the contact shoe of the control car. When passinga gap in the continuity of the power rail at certain rail crossings, rail-switches, track junctions or the like, the contact shoe temporarily runs off the power rail, only to resume its contact relation with the rail not without causing something of an impact thereon. Also when in operation over longer distances and at high speeds the sliding contact movement of the contact shoe may have some disturbing influence upon the structure of the power rail.

Whatever the concept of the compound stresses in their effect upon the power rail, in a mechanical, electrical or magnetic, or perhaps in a thermic sense, these forces also appear to give rise to an undesirable phenomenon known as rail creeping. This refers to the tendency of rail section to move in longitudinal direction by imperceptible degrees and do so in spite of a relatively tight anchoring grip of the ordinary rail clamping devices.

One object of this invention therefore aims to realize the design of a rail supporting structure which is substantially insusceptible to the aforementioned injurious and possibly destructive influences, and which tends to subdue, absorb or eliminate rail creepage.

To this end an improved support for the powerrail is designed with a minimum of unbalanced connections that is to say a minimum of connections which are affected by the free play of extraneous forces or stresses. Combined with the power-rail it constitutes a well connected unit which is composed of suitably coordinated elements each of which is adapted to assume an appropriate portion of that duty which is otherwise imposed upon the support as a whole. In this way transverse and longitudinal stresses, vibrations and rail creeping are effectively compensated for, counteracted, and absorbed. More specifically this means that such factors as stress resistance, rail-gripping power, and electrical insulating power, are reapportioned to certain structural elements in such a manner that compound strains upon one element are reduced and simplified and consequently their cumulative injurious efiect upon the structure as a whole diminished. The elements of the supporting structure are arranged relative to each other and relative to the rail in a manner which makes available their optimum of mechanical or strength efficiency.

According to one feature the support for the power-rail is in the character of a truss structure having the desired insulating properties, and which is attachable to the bottom portion or flange of the power-rail. The rail and the supporting truss-structure will have a common vertical plane of acting forces or stresses with regard to certain tension and compression members which constitute the truss structure. That is to say, the stresses will be substantially balanced and symmetrical.

According to another feature the insulator links have embodied therein suitable tension adjustment means in the way of certain telescopic screw arrangements in the links.

More specifically, a pair of clamping devices is spaced at suitable distance from each other, each being effective to grip across and around the lower flange or bottom of the rail. These clamp devices form anchoring points for the respective outer ends of symmetrically arranged insulator links or brace members which slope rather gently towards a base plate or member or intermediate link to which they'are connected. It is a structural feature that the base plate has a manifold function in that it interconnects the inner ends of the insulator links, furthermore in that it positions and maintains properly seated the insulator body upon which sustains the weight of the power rail, without necessitating additional positive connections for that purpose, and still further in that it serves as the anchor plate or footing which may be bolted to the ground or more preferably to one of the usual wooden track cross ties or sleepers.

It is an aspect of advantage that the present improved structure of an insulator support does away with a special connection between the insulator body and a base plate therefor, in view of the fact that commercial types of supports for the present purpose need a metal filler of molten and solidified lead or the like as a connection between the insulator body and the insulator baseplate.

The invention possesses other objects and features of advantage, some of which with the foregoing will be set forth in the following description. In the following description and in the claims, parts will be identified by specific names for convenience, but they are intended to be as generic in their application to similar parts as the art will permit. In the accompanying drawings there has been illustrated the best embodiment of the invention known to me, but such embodiment is to be regarded as typical only of many possible embodiments, and the invention is not to be limited thereto.

The novel features that I consider characteristic of my invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of a specific embodiment when read in connection with the accompanying drawings in which:

Fig. l is a longitudinal elevation of an assemr bly of the power rail and the supporting structure.

Fig. 2 is a top view taken upon Fig. 1.

Fig. 3 is a cross-sectional View taken along 33 in Fig. 1.

Fig. 4 is a side view similar to Fig. l with certain modifications of the insulator links or braces.

Fig. is cross-sectional view taken along 55 in Fig. 4.

Fig. 6 is a plan View taken upon Fig. 4 and showing more clearly the modified arrangement of the insulator links or braces.

In Figs. 1 and 2 is shown a power rail l3 hav ing a top or contact flange I I, a bottom flange l2 and a web-portion l3, to be mounted upon an insulating support having the characteristics of a unitary truss structure is shown in the side view of Figure 1. It includes an insulator body or compression member l4 having a truncoconical head portion l5 and a foot portion I6. The footportion I6 is shown to rest in a dished member I! having a centrally rising protrusion or base I8 to fit into a corresponding recess in the bottom of the insulator body M. A disc member l9 having prongs 2G and 2| crowns the insulator body and fits to the bottom portion or flange l2 of the power rail. The dished member I! has laterally arranged a rising portion or stem 22 shown to be of U-shaped cross-section and which serves to support a wooden rail protector or guard 23. Directly subjacent to the dished member I 'I is a base plate or body portion 24 formed with ears or eyelets 25 and 25. A pair of WOOd screws 21 and 28 are shown to anchor the dished member I! together with the base plate 24 down upon a wooden rail tie or block 29 settled upon a foundation indicated at 29c.

A pair of opposedly arranged links 30 and 3| flanking the compression member l4 are articulated or fastened at their inner ends to the ears 25 and 26 respectively by pins 32 and 33 secured with cotterpins 32a and 33a. At its outer end each link anchored to the rail bottom portion by means of a clamping device 34 or 34a. respectively shown more clearly in the enlarged detail of Fig. 3, and which includes a pair of clamping jaws 35 and 36. As shown in Fig. 3 the shape of a jaw is adapted to fit hooklike over and around a flange portion of the rail bottom in such a manner that points of gripping contact are established between each jaw member and the rail as at 3'! and 38. A screw bolt 39 with nut 40 and spring washer 40a connects the jaws 35 and 36. A recess or passage ll is formed by the inner ends of the jaws, the rail bottom, and the bolt 39, in which recess or passage lodges the head of a threaded eye bolt 42 which forms the outer end of the link 3|. The link 3| furthermore includes a female threaded portion 43 which is preferably rotatable although anchored in a claw member 44. The central and longest portion of the link 3l is formed by a rod 45 of insulating material such as wood or others and which dovetailed into the claw member 44. The inner end of the link is correspondingly formed with another claw member 46 by which it is articulated to the ear 26 of the base plate 24. The entire arrangement of the support is substantially symmetrical to and vertical registry with the longitudinal center line of the power-rail.

The Figures 4, 5 and 6 show a modification in the symmetrical arrangement of the bracing or tension links and the method of connecting their respective inner and outer ends. A power rail 41, an insulator body 48, a crown mmeber 49, anchoring bolts 50, and a rail tie 5| are substan tially the same as just described. A dished member 52 is modified in that it has ears 58 and 54 extending directly therefrom. Furthermore the connection is arranged to accommodate at each side of the insulator body 48 a pair of parallel and symmetrically arranged links 55 and 55 hinged to the respective ends of a cross member 51 which is pivoted or fulcrumed upon the car 53. The link itself is substantially the same as described in connection with Figures 1, 2 and 3, including a telescoping tensioning device, except that the outer end of each' link is formed by a bifurcated eye bolt 54.

In order to anchor the outer ends of these links the associated rail clamping jaws 55 and 56 thereof (see Fig. 5) are provided with ears 55a and 55a to register with the bifurcated eye bolts 54 when operatively or pivotally connected by the respective pins 51 and 58 secured by cotterpins 51a and 58a. The cross-sectional area of the tension links at each side of the rail support is thus doubled as compared with the single link connection disclosed in Figures 1 to 3. That is to say the modified arrangement provides for greater total mechanical or tensile strength of the link connection in view of the fact that the insulating material which forms a portion of the length of the links is not equal in its tension transmitting capacity to the tougher or metal portions of the connection.

Reverting to Figs. 1, 2 and 3, the procedure of assembling and mounting the elements of the rail support is substantially self-evident from the previous description. However, it should be noted that the organization is such that the elements form a truss or bracing system which is essentially balanced as regards internal stresses in that the outer links 30 and 3| and the intermediate link or baseplate 24 (see Fig. 1) form a chain or catenary which is anchored symmetrically with respect to the longitudinal center line of the rail and which links may be tensioned or loosened by turning the polygon head of the threaded female member 63. With the clamping devices tightened and the proper tension applied to the links 30 and 3| the insulator body or compression members 48 appears to be firmly embraced between the rail II and the catenary or link system suspended therefrom, the rail sustaining insulator 48 being properly positioned as through its engagement at the bottom with the central upright protrusion l8 and at the top by the crowning disc l9 whose prongs or lugs 2|] and 2| embrace between them the bottom flange I2 of the power rail.

Consequently it can be said that a wide base of anchorage is established between the two anchoring devices 34 and 34a, in order to counteract the tendency of rail creeping. The stress diagram of the supporting structure is favorable in view of the gentle slope of the links relative to longitudinal forces tending to displace the rail, and in View of the interconnection of the links through the baseplate 24. It is furthermore favorable from a view point of stresses, that this compression element is merely held in place by top and bottom surface contact with the associated elements, and arranged to register with the plane of these elements, which renders it relatively free from other than compression stresses.

It is also noted that the supporting structure including the tension links 30 and. 3| and the compression member I4, is substantially selfcontained and unitary with the power rail when attached thereto, so that in principle it can be moved together with the power-rail when separated from the wooden cross tie 29 or else the wooden cross tie may be separated leaving the supporting structure otherwise undisturbed.

I claim:

1. A supporting structure for the power rail extending parallel to the track rails of electric train systems, said structure adapted to rest upon a base such as a rail cross tie, which structure comprises an insulator body adapted to sustain the weight of the rail from the bottom thereof, a base member underlying said insulator body, a pair of substantially symmetrically and opposedly arranged non-conducting bracing connections extending from said base member to said rail, and means for tensioning said connections as between said base and said rail, said supporting structure and said rail forming a self-contained truss system.

2. A supporting structure according to claim 1, in which the connections extend substantially in vertical registry with the longitudinal center line of said rail.

3. A supporting structure according to claim 1, in which the rail has a double flanged bottom portion, and in which the tensioningmeans comprises clamping devices adapted to embrace said flanged portion and to which clamping devices said connections are anchored in symmetrical fashion.

4. A supporting structure according to claim 1, in which said insulator body is provided with interlocking and positioning means relative to the rail and to the base member, which means become effective when said connections are in place.

5. A supporting structure according to claim 1, in which the base member has a rising centrally arranged cylindrical positioning portion adapted to lodge in a corresponding cavity in the bottom portion of the insulator body for positioning the same when the same is seated upon said base member.

6. A supporting structure according to claim 1, in which the base member has symmetrically arranged eyelets to serve for the mounting of said bracing connections.

'7. A supporting structure according to claim 1, in which a clamping device is associated with each of said connections for anchoring the same upon a corresponding bottom portion of the power rail, which clamping device includes a pair of symmetrical clamping jaws flanking the bottom portion of said rail and also includes a horizontal bolt connection to establish the rail gripping engagement of the jaws, each said connection having at its outer end a curved portion to fit over the connecting bolt and to lodge in a recess centrally formed by the inner end portions of said clamping jaws underneath the rail bottom.

8. A supporting structure for a power rail which extends parallel to the track rails of train-systems, said structure adapted to rest upon a base such as a rail cross tie, which structure comprises a truss formation having insulating qualities and attachable to the bottom portion of the power rail and extending longitudinally thereof in a vertical plane, said truss formation including a pair of symmetrical tension elements and. a centrally arranged compression element, all elements structurally coordinated in a common plane of acting forces, when attached to the rail, said tension elements substantially converging upon the lower portion of said compression element approximately in the way of an inverted triangle.

9. A power rail supporting structure according to claim 8, in which the truss formation consists of a detachable catenary like tension system of tension elements suspended or anchored from the bottom portion of the power rail, and a compression element interposed between said catenary system and the bottom of the rail and held in place by the tension of said catenary system.

10. A power rail supporting structure according to claim 8, in which the truss formation consists of a detachable relatively shallow catenary like tension system of link elements including a pair of opposedly arranged relatively long inclined links, and a relatively short and substantially horizontal link interconnecting said long sloping links, and a compression member or spacer interposed between said short link and the bottom portion of the rail.

11. A supporting structure according to claim 8, for a power rail having a double flanged bottom portion and a fiat bottom surface, in which the truss formation consists of a detachable relatively shallow catenary like tension system of link elements, including a pair of opposedly arranged relatively long sloping links, and a relatively short, flat and substantially horizontal link interconnecting said long sloping links, a relatively short and wide rail supporting compression elements interposed between the horizontal faces of said short and flat link and of the rail bottom, with the addition of means for securing predetermined positive interengagement of said flat faces with the corresponding flat top and bottom faces of said compression element.

12. In a power rail supporting structure having a rail supporting compression element, a pair of opposedly arranged inclined tension links flanking said compression element, said links having means provided at their inner end portions adapting the same to be anchored at respective points adjacent the lower portion of said compression element, there being also provided means for attaching the outer end portions of said tension links at respective points to said rail; a base member subjacent to said compression element and comprising a body portion associable with and corresponding to the bottom face of said compression element, and a pair of ears opposedly arranged to extend from said bottom portions and adapted for connection therewith of the inner end portions of said tension links.

13. In a power rail supporting structure having a rail supporting compression element of relatively considerable width and provided with a substantially flat bottom face by which to be seated, a pair of opposedly arranged inclined tension links flanking said compression element, said links having means provided at their inner end portions adapting the same to be anchored at respective points adjacent the lower portion of said compression element, there being also provided means for attaching the outer end portions of said tension links at respective points to said rail; a base member subjacent to said compression element and which comprises a flat body portion substantially corresponding to the flat bottom face of the said compression element, and a pair of similarly flat ears opposedly arranged to extend from said body portion for connection therewith of the inner ends of said tension links.

14. In a power rail supporting structure having a rail supporting compression element of relatively considerable width and provided with a substantially fiat bottom face by which to be seated, also having a pair of opposedly arranged inclined tension links flanking said compression element, said links having means provided at their inner end portions adapting the same to be anchored at respective points adjacent the lower portion of said compression element, there being also provided means for attaching the outer end portions of said tension links at respective points to said rail; a base member subjacent to said compression element and which comprises a flat body portion substantially corresponding to the flat bottom face of the said compression element, and a pair of similarly flat ears opposedly arranged to extend integrally from said body portion for connection therewith of the inner end portions of said tension links.

WILLIAM C. BANKS.

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