US2721034A - Tie plate hold-down clamp - Google Patents

Description

Oct. 18, 1955 w. .1. BISHOP TIE PLATE HOLDDOWN CLAMP Filed Feb. 26, 1953 JNVENTOR.

United States Patent O signments, to Poor & Company, Chicago, 11]., a corporation of Delaware Application February 26, 1953, Serial No. 338,970

4 Claims. (Cl. 238-349) This invention relates to a tie plate hold-down clamp and particularly to a clamp structure including a resilient element adapted to be used in cooperation with a conventional railway cut spike to resiliently clamp a tie plate in its operative position on a railway cross tie.

Clamp structures heretofore used for clamping railway tie plates to cross-ties have ordinarily included a spring clip combination for clamping a railway rail to the tie plate. That is to say, one portion of the spring clip element ordinarily overlies the base portion of the rail and exerts resilient pressure thereon to hold the rail clamped to the tie plate. Another portion of the spring clip is compressed between the head of a spike, ordinarily a screw spike, and the top face of the tie plate to hold the plate clamped to the top surface of an underlying cross-tie. Such combination structures contemplate constant clamping action on the rail base portion and therefore depart from the customary practice of providing slight clearance between the top surface of the rail base flange and the hold-down spikes, such clearance being provided to permit limited movement of the rail relative to the tie plate during the normal vertical wave movement produced in a rail during the passing of a train thereover. The failure of such combination structures to permit the rail to move vertically relative to the tie plate results in transmitting the vertical wave movement of the rail to the cross-tie and thereby imparts pumping movements to the cross-tie in the ballast of the road bed. Such pumping movements are highly objectional, since the vertical movements of the cross-tie in the ballast permits particles of ballast to move under the cross-ties in a manner to cant or twist them out of proper alignment and thereby produce an uneven surface condition in the trackway.

According to my invention the tie plate is clamped to the cross-tie independently of any clamping action on the rail. Consequently the rail hold-down spikes can be so driven as to provide the usual clearance to permit slight vertical movement of the rail relative to the tie plate during the so-called wave movement of the rail. Also the resilient clamp of the present invention can be made of relatively light stock, since it functions only to clamp a tie plate to a cross-tie, as distinguished from a rail clamping pressure and is not subjected to any strains incident to the vertical movement of the rail or the tie pumping movements hereinabove described.

A principal object of the present invention is to provide a tie plate hold-down clamp of simplified construction which will be free of the objections above discussed and which, because of the special features of construction of the spring element of the clamp, makes it practical to use the spring element in combination with a conventional form of cut spike and without provision of any auxiliary anchoring means for the spike.

A preferred embodiment of the invention is illustrated in the accompanying drawing wherein:

Fig. l is a plan view of a tie plate secured to an underlying cross-tie by means of a spring clamp structure made in accordance with this invention and illustrating also the 2,721,034 Patented Oct. 18, 1955 base portion of a railroad rail secured in its normal operative position on the tie plate;

Fig. 2 is a view taken substantially on line 2-2 of Fig. l, the base portion of the rail being shown in section and a portion of the tie plate and hold-down clamp being shown in section for purpose of clearness;

Fig. 3 is a vertical sectional view taken substantially on line 33 of Fig. 2.

Referring to the drawing: 10 designates the base portion of a railroad rail seated on a conventional form of tie plate 11, the latter of which is secured to an underlying wood cross-tie 12 by means of the improved hold-down clamp structure of the present invention designated generally by the minerals 13-13. V

The tie plate 11 is preferably, though not necessarily, provided with spaced shoulders 14-14 which define a seat 15 for supporting the base portion of a railroad rail. The shoulders 1414 resist lateral movement of the rail base and the base is held in its proper position on the tie plate by means of two or more conventional railway spikes 16 of the drive-in type. These spikes are driven into the cross-tie 12 through punched openings 17-'17 formed in the plate. In the present disclosure only two spikes 1616 are shown, but, if desired, additional spikes may be driven into the tie through punched openings 17 '17 It will be observed that the undersurface of the spike heads 18-18 are positioned to provide a clearance 19 between the spike head and the top surface of the rail base so that the rail has capacity for a limited vertical movement relative to the tie plate. This clearance is desirable in track constructions so as to prevent the vertical movement of the rail, during the normal wave movement thereof, from exerting vertical force on the spikes 1616 in a manner tending to produce a pumping action (up and down movement) of the cross-tie 12 in the ballast 20 of the roadbed (Fig. 3).

When a rolling load of substantial weight is passed along railroad rails the weight tends to deflect the rails downwardly between the adjacent cross-ties and this donward deflection results in a similar upward bowing of the rails above the crossties. It is this movement that is generally termed wave movement of a rail. It is because of this movement of the rail 'that it is desirable in railway track constructions to provide a clearance such as indicated 'at 19 between the top surface of a rail base and the under-surface of the hold-down spike. Otherwise, when the cross-tie is tar'nped tightly in the ballast 20 the normal upward movement of the rail tends to partially extract the rail hold-down spikes from the cross-tie. The upward movement of therail also tends to impart the said pumping movements to the cross-ties. Such movements of the cross-ties permit particles of the ballast to find entrance beneath the crossties and eventually distort the position of the cross-ties in the roadbed, thereby making it necessary to r'e-align the cross-ties and re-establish the desired level of the roadbed.

The improved tie plate hold-down clamp of the pres ent invention is designed to perform its hold-down function on the tie plate only, and thereby makes it practicable to support the railroad rail in the conventional manner hereinabove described and at the same time prevent vertical movement of the tie plate 11 on the cross-tie 12.

The improved hold-down clamp of the present invention includes, in each case, a leaf spring 21 formed at opposite ends with return bent portions 22 which form open loops and provide curved surfaces 23 23 for bearing against the top surface 24 of a tie plate. The said loops impart to the spring an upwardly bowed configuration relative to the tie plate so as to provide a substantial clearance between the central portion of the spring and the plate. The central portion of the spring leaf is formed with a depression 25 conforming substantially to the contour of the under-surface 26 of a conventional drive-in railway spike 27 so that the under-portion of the spike head can nest within the depression 25 and thereby provide: an interlocking engagement to prevent relative rotational movements of the spike and spring. The depth of the depression 25 'permits'the spike shank to be driven further into the cross-tie than would be otherwise possible and the configurationof the depression provides a large area contact with the under-surface of the spike head so as to minimize wear. The central portion of the spring leaf is also formed with a square central opening 28 adapted to receive the rectangular shank portion of the spike 27. The marginal portions of the opening 28 are in the form of depending flanges 29 which provide guide surfaces forthe shank portion of the spike 27, the said spikes being driven into the cross-tie 12 through a rectangular punched opening 30 formed in the tie plate 11.

In Fig. 2 of the drawing, it will be observed that the spike 27 at the left of the figure is only partially driven into the cross-tie 12 and that the lower edge 31 of the downturned flange 29 is spaced upwardly from the top surface 24 of the tie plate. However, when the undersurface 26 of the spike head seats within the depression 25 the central portion of the leaf spring 21 is flexed downwardly until the edge 31 of said flange 29 engages the top surface of the tie plate and thereby provides a stop for limiting the flexing of the spring 21. This operative position of the leaf spring 21 is illustrated at the right of Fig. 2.

When the spikes 27 are driven to the limit of their applying movement (shown at the right of Fig. 2) the tie plate 11 is rigidly clamped to the top surface of the cross-tie 12 by virtue of the engagement of the stop surface 31 with the plate and the return bent end portions of each leaf spring 21 exert resilient pressure against the top surface of the tie plate at opposite sides of the spike 27 associated with said leaf spring. The end portions of the spring thereby function as spring followers to hold the tie plate firmly against the top surface of the cross-tie 12 and take up any loosenessvthat may occur in the event that the wood fibersof the crosstie become compressed as a result of the weight of the railway equipment'passing along the rails The spring pressure exerted by the leaf springs 21 prevents vibratory movements of the tie plate on the cross-tie and, therefore, minimize the wear on the cross-tie incident to such vibratory movements. After the tie plate 11 becomes firmly seated on the cross-tie 12 and the top surface of the tie plate has been subjected to the normal compression of its fibers, spikes 2727 may be driven further into the cross-tie so as to re-engage the stop surfaces 3 131 against the top surface of the tie plate. The hold-down clamp structure will thereafter maintain this position since the reflex spring pressure of the clamp structure will beinsufficient to loosen the position of its associated spike 27 in the cross-tie. At the same time the rail hold-down spikes 16-16 may be driven further into the cross-tie so as to re-establish the proper clearhead of the spike and resiliently pressing the end portions of the spring against the plate to clamp the plate to the cross-tie, a depending flange surrounding a central opening and providing a stop engaging the tie plate to limit the downward flexing of the leaf spring and defining the limit of the applying movement of the spike into the crosstie, whereby the tie plate is clamped rigidly to the crosstie by the holding force of the spike exerted through said stop and the ends of said leaf spring function as spring followers to take up any looseness thereafter occurring 7 between the plate and cross-tie.

2. The combination with a railway tie plate having a spike opening therein and a wood cross-tie on which the tie plate is supported, of a tie plate hold-down clamp comprising a railway track spike provided with a shank driven to a predetermined distance into said cross-tie through said spike opening and provided with a head portion for receiving the driving force applied to the spike, and a leaf spring provided with a central opening to receive said spike shank and having end portions seating on the plate at opposite sides of said spike opening and bowed'upwardly intermediate its ends with the bowed portion positioned in a downwardly flexed position beneath the head of the spike and resiliently pressing the end portions of the spring against the plate to clamp the plate to the cross-tie, a depending flange surrounding a central opening and providing a stop engaging the tie plate to limit the downward flexing of the leaf spring and defining the limits of the applying movement of the spike into the cross-tie, whereby the tie plate is clamped rigidly to the cross-tie by the holding force of the spike exerted through said stop and the ends of said leaf spring function as spring followers to take up any looseness thereafter occurring between the plate and crosstie, there being a depression in the spring leaf at a location beneath the head of the spike and receiving a portion of said spike head, whereby the spike and leaf spring are interlocked to prevent relative rotation when the clamp is in its applied position.

3. The combination with a railway tie plate having a spike opening therein and a wood cross-tie on which the tie plate is supported, of a tie plate hold-down clamp comprising a railway track spike provided with a shank driven ance 19 between the top surface of the rail base and the under-surface of the spike heads 18-18.

I claim:

1. The combination with a railway tie plate having a spike opening therein and a wood cross-tie on which the tie plate is supported, of a tie plate hold-down clamp comprising a railway track spike provided with a shank driven to a predetermined operative position into said cross-tie through said spike opening and provided with a head portion for receiving the driving force applied to the spike, and a leaf spring provided with a central opening to receive said spike shank and having end portions seating on the plate at opposite sides of said spike opening and bowed upwardly intermediate its ends with the bowed portion positioned in a downwardly flexed position beneath'the to a predetermined distance into said cross-tie through said spike opening and provided with a head portion for receiving the driving force applied to the spike, and a leaf spring provided with acentral opening'to receive said spike shank and having end portions seating on the plate at opposite sides of said spike opening and bowed upwardly intermediate its ends with thebowed portion positioned in a downwardly flexed position beneath the head of the spike and resiliently pressing the end portions of the spring against the plate to clamp the plate to the cross-tie, a depending flange surrounding a central opening and providing a stop engaging the tie plate tolimit the downward flexing of the leaf spring and defining the limit of the applying movement of the spike into the'cross-tie, whereby the tie plate is clamped rigidly to the'cross-tie by the holding force of the spike exerted through said stop and the ends of said leaf spring function as spring followers to .take up any looseness thereafter occurring between the plate and cross-tie, there being a depression in the spring leaf ata location beneath the head of the spike and having a configuration corresponding with the contour of the undersurface of the spike head and receiving the spike head in nesting engagement therein, whereby the spike and leaf spring are interlocked to prevent relative rotation when the clamp is in its applied position and the spike head has maximum bearing area engagement with the leaf spring. 7

4. The combination with a railway tie plate having a spike opening therein and a wood cross-tie on which the tie plate is supported, of a tie plate hold-down clamp comprising a railway track spike provided with a shank of rectangular cross section having a downwardly tapered thickness at the upper end thereof and driven into said crosstie through said spike opening and provided with a head portion for receiving the driving force applied to the spike, and a leaf spring provided with a central rectangular opening to receive said spike shank and having end portions seating on the plate at opposite sides of said spike opening and bowed upwardly intermediate its ends with the bowed portion positioned in a downwardly flexed position beneath the head of the spike and resiliently pressing the end portions of the spring against the plate to clamp the plate to the cross-tie, a depending flange surrounding the central opening and defining a tapered sleeve corresponding to the shape of the upper portion of the spike shank and providing a stop engaging the tie plate to limit the downward flexing of the leaf spring and the applying movement of the spike into the cross-tie, whereby the tie plate is clamped rigidly to the cross-tie by the holding force of the spike exerted through said stop and the ends of said leaf spring function as spring followers to take up any looseness thereafter occurring between the plate and cross-tie, there being a depression in the spring leaf at a location beneath the head of the spike and having a configuration corresponding with the contour of the undersurface of the spike head to receive the spike head in nesting engagement therein, whereby the spike and leaf spring are interlocked to prevent relative rotation when the clamp is in its applied position and the spike head has maximum bearing area engagement with the leaf spring.

References Cited in the file of this patent UNITED STATES PATENTS 476,241 Bouscaren June 7, 1892 1,453,507 Kimball May 1, 1923 1,641,059 Tausch Aug. 30, 1927 1,793,116 Monroe Feb. 17, 1931 1,815,815 Vosslok July 21, 1931 1,836,713 Hewett Dec. 15, 1931 2,056,251 Cairncross Oct. 6, 1936 2,072,176 Monroe Mar. 2, 1937 2,365,545 Graham et al Dec. 19, 1944 2,524,805 Jack Oct. 10. 1950

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