US3521576A - Bridge plate securing mechanism - Google Patents

Description

July 21, 1970 R. H. MURRAY BRIDGE PLATE SECURING MECHANISM 2 Sheets-Sheet l I Filed Nov. 16. 1967 INVENTOR Roerf/ Murray Juy 21, 1970 R. H. MURRAY` BRIDGE PLAT E SECURING MECHANISM 2 Sheets-Sheet 2 Filed Nov. 16, 1967 INVENTOR Robe/'f /76 Murray United States Patent O U.S. Cl. S-458 4 Claims ABSTRACT OF THE DISCLOSURE A mechanism for counterbalancing the weight of a hinged bridge plate while it is being moved between its lowered and raised positions, and for securing said bridge plate resiliently when in its raised or storage position.

BACKGROUND OF THE INVENTION The field of art to which the invention pertains is that of railway rolling stock equipped with bridging devices between adjacent coupled cars so as to permit safe passage of Wheeled vehicles thereover.

In piggyback operations, hinged bridge plates serve as trackways between flat cars in order to permit trailers to be loaded or unlooaded longitudinally on the cars.

The increasing use of long draft gears to cushion at cars in piggyback service has resulted in creating greater than normal spans between the cars, which in turn has rendered necessary the use of longer and heavier bridge plates than heretofore.

As the bridge plate is normally required to be in a horizontal position only during loading and unloading operations at terminals, one end of each bridge plate is conventionally hinged at the end of a car, and the plate is raised to a vertical storage position for safety and convenience when the car is moving.

As some of the newer bridge plates are, for example, about 70 long, 28" wide, and 5" deep, and must be able to support great weights, their own weight will be in the neighborhood of 250 pounds apiece. Because the effort required to lift such a bridge plate manually is no longer practical for one man, the subject bridge plate is counterbalanced to assist its being handled.

It has been conventional to latch the bridge plate in its vertical storage position when not in use by means of a downwardly slidable locking pin or cane bolt on one side of the plate, which pin is inserted into an upright socket on the car deck.

The many instances of breakage involving the locking pin have been the greatest objections to its use. The chief cause of breakage is that when a bridge plate equipped with a locking pin has been raised to its storage position and the car is moving, the pin is usually loose enough in its socket to allow the pin to rattle about therein. The resultant impact and wear between the pin and the socket then enlarges the hole in the socket. This action increases the effect of further such impacts to the point where there is structural failure of the parts.

SUMMARY OF THE INVENTION In this invention, a helper spring mechanism counterbalances most of the weight of a bridge plate, thereby reducing the physical effort required to lift the bridge plate and cushioning its descent. When the bridge plate is fully raised, a buffer spring mechanism holds the bridge plate upright and also permits a limited range of controlled swinging movement longitudinally on the car until a release device is actuated. The bridge plate is easily demountable for repairs or replacements.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary top plan view of a railway car end having mounted thereon a lowered bridge plate 3,521,576 Patented July 21, 1970 equipped with the counterbalancing and securing mechanism of the present invention;

FIG. 2 is a side elevational view of the invention taken generally on the line 2 2 of FIG. l, showing the helper spring but for clarity omitting the buffer spring and the interior portion of the guide bar;

FIG. 3 is a vertical longitudinal section on the line 3-3 of FIG. 1, with the bridge plate being shown in lowered position;

FIG. 4 is a vertical longitudinal section on the line 4-4 of FIG. 5, and lis similar to FIG. 3, except that the bridge plate is shown in fully upright position;

- FIG. 5 is a fragmentary end elevation of the car showing the release mechanism for the bridge plate;

FIG. 6 is a sectional detail view of the release `mechanism when the bridge plate is in lowered position;

FIG. 7 is a sectional detail view, taken on the line 7-7 of FIG. 5, of the release mechanism while the bridge plate is in upright position;

FIG. 8 is a sectional detail view of the strap hinge mounting of the bridge plate;

FIG. 9 is a typical lateral section of the bridge plate; and

FIG. l0 is a fragmentary vertical longitudinal section on the line 3-3 of FIG. l, with the lowered bridge plate being shown in positions for bridging to a car of normally lower deck height (solid lines) or greater deck height (dotted lines) than the car on which the bridge plate is hinged.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the parts designated by the reference numerals in the drawings, the portion of the railway car 1 shown particularly in FIGS. 1 to 5 of the drawings is of a known type adapted for piggyback hauling operations,

and is conventionally provided with a low side sill 2, end sill 3, draft gear housing 4 continuous with center sill 5, and generally ilat deck 6.

The bridge plate 7, which functions primarily as a temporary extension of the car deck 6, may be conventionally fabricated from a carnbered top plate 8 supported longitiudinally on three formed channels 9, and provided with welded reinforcing pipe nosings 10 and 11 on opposite ends.

Upon opposite sides of the inner end of the bridge plate 7 are mounted the longitudinal arms 12 of a pair of bell cranks 13 of modified gooseneck configuration, each bell crank including a lower arm 14 projecting rearwardly and downwardly about 40 when the bridge plate 7 is horizontal and extending through apertures 15 and 16 in the car deck 6. Said arms 14 are attached as by bolts 17 to end levers 18 and 18', said end levers being mounted upon opposite ends of a pipe shaft 19. This pipe shaft 19 extends laterally beneath the deck y6 adjacent the apertures 15 and 16, and is pivotally mounted beneath the deck 6 as by a pair of strap hinges 20 secured on the underside of said deck. The bottom portions of the strap hinges 20 are depressed below the underside of the deck 6 to a sufficient depth to provide clearance for a limited vertical movement of the pipe shaft 19 as hereinafter described.

The lower portions of the end levers 18 and 18' are inclined toward the end sill 3 when the bridge plate 7 is raised for storage and conversely when said bridge plate 7 is substantially horizontal.

Supplemental lifting torque from a -generally horizontal resilient strut 23 beneath the deck is communicated to the bridge plate 7 through a pair of centrally disposed depending levers 24 fixed to the pipe shaft 19. Said levers 24 swing rearwardly when the bridge plate 7 is being lowered.

--The resilient strut 23 of the present mechanism comprises an assembly of relatively shiftable telescoping pipes 25 and 26, with an outer (helper) coil spring 27 which enables the strut to counterbalance most of the weight of the bridge plate 7 as it is being lifted, and a coaxially disposed inner (buffer) double-acting coil spring 28 which holds the bridge plate 7 yieldably upright through the center lever arms 2'4.

Immediately behind the rearmost end of said resilient strut 23, a short longitudinally extending bracket 29 projects vertically downward from the underside of the car deck 6 and is Welded thereto adjacent to the longitudinal stitener 30.

Pivotally mounted on said bracket 29 by means of a shoulder bolt 31, nut 32 and cotter pin 33 is a spring seat member 34 against which bears the rear end of the outer (helper) spring 27 and to which is secured as by welding the inner pipe 25 of the resilient strut 23. Welded within the rear portion of said inner pipe 25 in spaced relation from the spring seat member 34 is a irst inner stop ring 35. Welded inside the front end of said inner pipe 25 is a second inner stop ring 45'.

The forward end of the outer (helper) spring 27 bears against a ring member 37 on the rear end of the outer pipe 26. The forward end of said outer pipe 26 is secured as by welding to a U-shaped plate member 38 having a large rectangular central hole 39 and a pair of forwardly projecting parallel side portions having aligned holes 40.

A flat guide bar 41 provided with an elongated forward slot 42 extends longitudinally rearwardly through the hole 39 into the inner pipe 25. An extended and reduced rear end portion of said guide bar 41 constitutes an arm 43 which is loosely encircled by the inner (buffer) spring 28 and the ring member 44. Engaging the first stop ring 35 is a circular washer 36 which is loosely mounted on the rear end of said arm 43 and is secured in place thereon by a through fastener such as a key or Cotterpin 45.

Welded about halfway between the inner end and the center of the pipe shaft 19 and projecting therefrom in a horizontal direction toward the end sill 3 when the bridge plate 7 is upright, is a cylindrical pin `46 having a through hole 47 in its outer end. Pivotally mounted on said pin 46 between a bushing 48 and a flat washer 49 secured by a cotterpin 50 in said hole 47 is a tubular sleeve 51 upon which are secured oppositely extending lateral arms 52 and 53. The left-hand arm shown in FIG. 5 terminates in a release pedal bar 54 which projects upwardly through the inboard deck aperture 15. The right-hand arm 53 comprises an outwardly and downwardly bent latching bar 55 having a downwardly slotted lower end portion 56 through which projects a pin 57. Said pin 57 extends through said downwardly slotted lower end portion 56 of the latching bar 55, through the holes 58 in the lower ends of the lever arms 24 and the holes 40 in the forwardly projecting side portions of the U-shaped plate member 38, and through the longitudinal slot 42 in the guide bar 41. The ends of said pin 57 are secured by washers 59 and Cotter-pins `60. The guide bar 41 is recessed at the forward end of said longitudinal slot in order to provide a socket 61 for receiving the slotted lower end portion 56 of the latching bar 55. Pressure from a spring 62 on the pin 57 will normally hold the bridge plate 7 to be pushed downward manually. As the pin 57 moves rearwardly in 4the slot 42, the pedal bar 54 is retracted completely beneath the car deck as shown in FIG. 2, so that the deck is not obstructed during loading.

When the bridge plate 7 is later being raised to its vertical storage position, the helper spring 27 assists the operator and the pin 57 slides forwardly in the slot 42,

until the bar snaps automatically into the socket 61 and the buifer spring 28 is automatically re-engaged. When both the springs 27 and 28 are thus operatively connected to the center levers 24, the bridge plate 7 will be held generally upright, with a range of about'lO" to 15 deflection in either longitudinal direction (see FIG. 4) being allowed to resist sudden shocks. The inner (buffer) spring 28 is pre-compressed on assembly between the washer 36 and the ring lmember 44, and is further compressed by the deliection of the raised bridge plate 7 in either a forward or backward direction.

When the bridge plate 7 is fully raised, the pipe shaft 19 on which it pivots rests on the inner bottom surfaces of the strap hinges 20, as shown in FIGS. 4, 5 and 7, there being no need to support the weight of a trailer. However, when the bridge plate 7 is completely lowered, and the combined weight of the bridge plate and the trailer wheels must be supported, the inner pipe nosing 10 of the bridge plate will bear on the car deck 6 at a point where it is strongly and rigidly supported by the underlying end sill 3. This will be true even though the outer end nosing 11 of said bridge plate 7 may be resting on the deck of an adjacent car that is either higher or lower than the car on which the bridge plate is pivoted, as in FIG. l0, so that the end sill 3 then serves essentially as a fulcrum. Inasmuch as the shaft 19 is free to move upwardly or downwardly in the strap hinges 20, it will cause the resilient strut 23 to be tilted accordingly about the bolt 31.

When cars of substantially equal heights are being bridged, the pipe shaft 19 will assume an intermediate position between the bottom face of the car deck 6 and the bottom of the strap hinges 20', as shown in FIGS. 2, 3, 6 and 8. The inner pipe nosing 1l)` of the lowered bridge plate 7 will still be supported primarily by the end sill 3.

Although I have shown my invention in conjunction with a long bridge plate, it will of course be understood that its value is not restricted in any way to use with long bridge plates per se. Some bridge plates though short are very heavy, in order to be able to support the largest prospective classes of trailers. The subject mechanism is adaptable to bridge plates of virtually any length, whether long or short, which would otherwise be too heavy to be lifted with ease manually.

This mechanism also has very little slack motion. It is therefore fully able to withstand the continued rattling motion encountered during transit without the harmful wear and tear experienced in the use of the previous cane bolt design.

It should be noted that the helper spring, the buffer spring, the latch and the latch release mechanism are all essential elements of the invention, although each element may be modified in detail. The functional requirements prevent the omission of any one of them.

The buffer spring 28 tends to hold the bridge plate in the vertical position but permits said bridge plate to be moved longitudinally in either direction under the forces of car acceleration and deceleration (about 4 Gs max.), wind pressure, and direct physical contact with an end of an adjacent trailer as it moves with its hitch. This service requires a very strong buffer spring, in order to enable a locking pin and socket to be dispensed with. But if the buffer spring were always attached to the bridge plate, it would be too powerful to permit the bridge plate to be lowered manually, or even to remain lowered. Therefore, the buffer spring has to be rendered easy toengage and be disengaged from operation by the latching and unlatching means.

The helper spring 27 needs only to be strong enough to partially overcome the force of gravity on the bridge plate and thereby enable one man to easily move the bridge plate between a vertical and a horizontal position.

What is claimed is:

.1. The combination, in a railway car having a deck and an end sill, a bracket beneath the deck and spaced from the end sill, a bridge plate, and lateral hinge means adjacent said end sill and mounting said bridge plate for angular rotational movement between a -fully raised substantially vertical transit position and a lowered generally horizontal loading position extending outwardly from said end sill, wherein the improvement comprises:

(a) a resilient strut pivotally attached to the bracket,

(b) depen-ding lever arm means seoured to the bridge plate adjacent the hinge means and connecting the strut and the bridge plate for transmitting force from the strut to the bridge plate,

(c) the aforesaid strut comprising a pair of coaxially arranged tubular members,

(d) a helper spring on said strut and having its effective force operatively applied through the outer of said tubular members to pivot means on the lever arm means so that the strut is enabled to counterbalance the greater part of the weight of the bridge plate as it is being lifted,

(e) a concentrically disposed buffer spring which exerts a residual compressive force, preloaded at assembly, so as to resiliently resist the rotational movement of the bridge plate in either direction from the fully raised position and thereby hold the bridge plate yieldingly upright in transit,

(f) a spring latch whereby the butler spring is attached yto the upright bridge plate, and

(g) latch release means actuatable to permit the buffer spring to be disengaged from the bridge plate when the bridge plate is to be lowered to a horizontal position.

2. The combination as claimed in claim 1, wherein the lateral hinge means comprises a shaft pivotally mounted in support means beneath the deck, there being sucient vetrical clearance in said support means to permit the rear end of the lowered bridge plate when under load to be supported by the end sill.

3. The combination as claimed in claim 1, wherein the means of subparagraph (g) includes (1) a pedal bar which normally extends above the deck when the bridge plate is in upright position and is disposed below the deck when said bridge plate is in horizontal position.

4. The combination as claimed in claim 3, wherein (a) the resilient strut is characterized by inner and outer tubular members and a longitudinally extending center guide member having its forward end provided with an elongated slot and terminating in a recessed socket portion,

(b) the lever arm means and the pedal bar extend through spaced apertures provided in the deck, (c) the inner tubular member concentrically encloses the center guide member, (d) the helper spring surrounds said inner tubular member and seats against the outer tubular member, (e) the buffer spring is mounted in said inner tubular member and seats against the center guide member, (f) the spring latch is characterized by pin means normally seated in the socket portion of the center guide member when the bridge plate is upright, and (g) the latch release means includes a depending arm pivotally mounted on the hinge means and operable by the pedal bar so as to release the pin means from the socket portion and permit it to travel freely within the elongated slot in the center guide member while said bridge plate is being raised from or lowered to a horizontal position.

References Cited UNITED STATES PATENTS 3,094,946 6/1963 Bain et al. 10S-458 3,216,372 1l/1965 Boone 105--458 3,216,373 11/1965 Boone 105-458 3,257,972 6/1966 Boone et al 10S-368. 3,323,472 6/1967 Boone et al 10S-368 3,327,650 6/1967 Bridges et al 10S-36S ARTHUR L. LA POINT, Primary Examiner R. A. BERTSCH, Assistant Examiner

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