US2231771A - Tie plate fastener - Google Patents

Description

Feb., 11, 1941. 2,231,771

C. E. MURPHY TIE-PLATE FASTENER Filed Feb. 24, 1958 l NToR l v Cla ence EMur2rl9h ATTO R N EYS Patented Feb. 11, 1941 y UNITED v.STATES PATENT oFFleE TIE PLATE FASTENER Clarence E. Murphy,`Cleveland, Ohio Application February 24, 1938, Serial No. 192,249 Y' 1y claim. (c1. 85430) This invention relates to tie plate fasteners The head 2 of the double threaded screw and more particularly to an improved screw spike spike has a squared end 9 preferably longitudiof the character used for securing railroad tie nally tapered which receives a suitable tool or plates towooden ties., implement (not shown) for turning the double An object of the invention is to provide a threaded screw spike when inserting it in the 5'- double thread screw spike to be employed as a wooden tie. A radially extending circular collar meansof fastening a steel tie plate to a wooden I0 is formed on the head 2 substantially at the tie with a minimum of damageto the wood, and juncture of the shank I with the head. A comwhich has a tight fit in the wood without splinpression spring II is received on a cylindrical 10 tering or cracking the latter. portion I2' of the .shank I which is adjacent the 10' Another object' is to provide a holding double collar IIl and is compressed between the collar thread screw spike for railroad tie plates which and the tie plate 3. may be removed and lreinserted in the same hole The main portion I4 of the shank I is of less in a tie and retain a snug fit therein. diameter than the portion I2 and a tapered por- Another object is to provide a railroad tie tion I 5 extends between thereduced diameter 15 plate double thread screw spike which seals the portion I4 and the large diameter portion I2. hole in which it is inserted to prevent the en- The lar'ge diameter portion I2 is of a length at trance thereinto of water and the like so as to least' equal to its diameter, and the tapered porprevent corrosion of the screw and rotting of tion I5 is substantially equal in length to the the wood, large diameter portion I2. 20 A further object is to provide a railroad double A pair or double set of spiral ribs or threads thread screw spike which may be inserted in a Il and I8 are formed' on the small diameter drilled hole and which cuts its own thread in the 4shank portion I4 and the tapered portion I5. wood.V Peferably the ribs or threads I'I and I8 are V- A still further object is to provide a railroad shaped in cross-section and have relatively sharp 25 double thread screw spike which is simple Ain crests I9. The ribsurfaces 2t, directed toward design and construction and inexpensive to the' head of the screw from the crests I9, are manufacture and one which is self-locking in set ata greater anglev With TSSDeCt t0 the axis place. Other objects and advantages will be- 0f the screw.v than surfaces EI directed toward come apparent from the following detailed dethe tip end 22 of the screw. This formation of 30 v scription of a suitable embodiment of the lnventhe threads Il and I8 effects a greater holding tion which is illustrated in the accompanying power and increases the resistance of the screw drawing, in whchj to being withdrawn from the tie il. Additionally, Figure lis a fragmentary sectional view showit allows for the screw spike to be turned into lng the railroad screw spike of the present inthe tie in less time than required to turn in 35 vention secured in a. railroad tie and holding a previously known types of Screw spikes.

railroad tie plate in position; The diameter across the crest of the threads Fig. 2 Yis a top View of a head of the double I'I and I8 is substantially uniform from one end thread screw spike; thereof to the other and preferably substantially Fig; 3 is a, fragmentary View showing the equal to the diameter of the shank portion I2. 40 modied form of head for the double thread For example, diameter A adjacent the tip end screw spike; and 22 of the screw is substantially equal to the di- Fig.. 4' is a plan View of the head shown in @meter B at the beginning 0f the tapered p01- Fig. 3 tion I5 of the shank lI. Additionally, the crest Referring to the drawing by numerals of refdiameter C across the crest of the threads I'I and 45 erence, the screw spike has a shank portion, in-1 3, Substantially at Vthe ends of the latter where dicated generally by the numeral I, and a head the '6211361' l5 0f the Shank merges into the large portion, indicated generally by the numeral 2 diameter portion I2 thereof, is substantially equal The shank I extends through a tie plate 3 into a to the Vcrest diameters A or B.' Thus, the threads wooden tie of the usual character. A rail 5 Il and IS do not materially deform or injure the V rests on the tie plate 3 and is secured by a spike wood fibers of the tie after the initial thread- 6. Bosses or similar formations l formed on cutting or OFmDg action 0f the portions 0f the the upper side of the tie plate 3 engage thevsides double threads adjeeent the tip end 0f the screw of the base of the rail 5 to prevent lateral movespike when the latter is being inserted into the ment of the rail. tie. v o5 In order that the crest diameter of the threads on the taper portion I5 of the shank does not increase over that of the diameter across the reduced diameter portion I4 of the shank, the threads II and I8 diminish in height as the diameter of the taper portion I5 increases.

In utilizing the double threaded railroad screw spike described, a hole 24 is flrst drilled in the tie 4. This hole is of a diameter slightly greater than the diameter of the portion I4 of the shank I but of less diameter than the portion I2 of the shank and the crest diameter of the double threads Il and I 8. Accordingly, in screwing the fastener into a tie there is substantially no dis? tortion of the wood fibers Iby the portionl I4 of the shank, and the holding action is effected by the double threads II and I8 which cut into the wood fibers forming a pair of spiral threads' in the wood. The shank portion I4 is substantially cylindrical and round in cross-section so that it merely turns as a shaft during the insertion of the screw, there being a clearance 25 between the walls of the hole 24 and the reduced diameter of the shank portion I4.

When the taper portion I4 enters the hole 24 the clearance 25 at the mouth of. the hole is gradually diminished until finally the taper portion I5 circumferentially engages the wall of the hole 24 and closes the latter, preventing the passage of water and the like into the hole. In effect the taper portion I5 of the shank is wedged into the hole 24 sealing the same against the atmosphere. Y

In the event that it is desirable to move th rail 5 or tie plate 3 the double threaded fastening screw spike may be removed merely by applying a suitable tool to the squared end 9 and rotating the same in a counterclockwise direction as viewed in Fig. 2. The screw spike is not injured in inserting it into or removing it from a tie so that it may be used a number of times, thus effecting a considerable economy. The novel construction of the shank portion of the screw effects an improved holding action and imparts increased strength thereto and greater durability in use.

Figs. 3 and 4 illustrate a modified construction of head for the screw spike. According tothis modification the upwardly projection portion to be engaged by a wrench or other turning implement is rectangular having opposite parallel sides 2l of greater width than opposite parallel sides 28. This construction enables pressure turning implements to obtain a greater grip on the screw spike and facilitates the inserting lof the spike into a railroad tie. Additionally, a hipped or peaked end is formed on the projecting portion and terminates in a point 29. An advantage of this modified head construction is that a positive grip is afforded for the implement or tool used in screwing the spike into or out of the railroad tie. It sometimes occurs that the socket of the wrench or tool becomes worn so that the corners of the square head shown in Figs. 1 and 2 become mutilated and rounded and the tool cannot obtain adequate grip thereon. With the rectangular head of Figs. 3 and4 .a non-circular cross-section obtains even when the corners thereof become rounded olf in use.

Numerous advantages are obtained by the provision of the substantially parallel, helically arranged threads I'I and I8. This double thread feature reduces the time required to insert'the screw spike in the tie or to remove it therefrom to about half that previously required for single thread fasteners having the same effective length of thread in frictional engagement with the wood of the tie. There is thus elected a material saving in labor when utilizing the spike of the present invention in constructing railroads. Additionally, when initially starting the tie Aplate fastener of the present invention into the wooden tie both of the threads I1 and I8 simultaneously bite into the Wood at the opening into the hole 24 and on diametrically opposed sides of the spike. This double action minimizes the tearing or splitting of the wood bres when starting the fastener so that it obtains a quicker grip in the Awood and when finally in place is secured in a tie with .greater strength.

The double thread construction also reduces the wear on the woodiibres of the tie since the length of the sliding engagement between the metal threads and wood fibres when inserting the spike is reduced in half over that which -prevails in single thread screw spikes having the same effective thread length. Accordingly, the individual wood bres have a more effective grip on the threads with the double thread construction than obtains with the use of but a single thread. Fasteners or spikes employing but a single thread on the shank must be driven by a hammer for a short distance to start them 4into the ho-le in the tie until the single thread engages the wood fibres of the tie with suflcient frictional force to cause the spike to feed itself into the hole when rotated. On the other hand the fastener of the present invention does not require that it be driven into the tie before rotating it by the tool. The diametrically opposed threads II and I8 have taper portions thereof adjacent the tip end 22 so that the screw spike affords .a sufliciently balanced grip in the hole of the -tie to effect a self-feeding action when the fastener is rotated to draw the fastener into the tie.

It is to be noted that the threads I I and I8 are set at such an angle with respect to the axis of the fastener that the latter must be inserted in ,a tie and removed therefrom by a twisting or screwing action and cannot be driven by a Sledge or mallet without injury to the wooden tie fibres by the threads. For example, the angle of the individual threads with respect to the axis of the screw spike is preferably more than 60 such for example as about as shown. This feature is advantageous in that the slope of the threads is such that the fastener does not work itself loose as would occur with threaded spikes of the character driven into the wooden tie solely by an axial force such as that of a Sledge Other modes of utilizing the-principles of the invention may be resorted to, change being made in the particular details shown and described, various modifications and alterations being contemplated, it being understood that the embodiments shown are given for purposes of explanation and illustration.

What I claim is:

A railroad screw of the character described to be driven by a suitable tool and having a head and a shank, said shank comprising a substantially cylindrical body portion of substantially uniform diameter from end to end thereof and a tapering frusto-conical portion at the tip end of the shank providing a relatively blunt. end thereon, and a pair of helical threads formed integrally on the shank and disposed in circumferentially spaced parallel relation to one anev merge With the surface of said frusto-oonical end portion short of the extreme tip end of said shank portion, whereby the crests of the tapered ends of both threads substantially simultaneously engage the Wall portions of a railroad tie hole having a smaller diameter than the largest crest diameter of the threads and intov which the screw may be initially inserted and started by hand and serve to progressively draw the cylindrical portion of the shank into the hole upon turning of 10 the screw in the hole.

CLARENCE E. MURPHY.

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