SPIKE PULLER AND METHOD FOR PULLING A RAILROAD SPIKE OF A TRACK

Abstract

A spike puller for pulling a railroad spike of a track includes a housing, a linear displacement unit mounted at the housing, and a claw unit for gripping the railroad spike. The claw unit is displaceable in a linear manner relative to the housing in a displacement direction by using the linear displacement unit. The linear displacement unit includes a hollow tube which is guided in the housing. A method for pulling a railroad spike of a track is also provided.

Claims

1. A spike puller for pulling a railroad spike of a track, the spike puller comprising: a housing; a linear displacement unit mounted at said housing, said linear displacement unit including a hollow tube guided in said housing; and a claw unit for engaging a railroad spike, said claw unit being displaceable by said linear displacement unit in a linear manner relative to said housing in a displacement direction.

2. The spike puller according to claim 1, wherein said hollow tube of said linear displacement unit is exactly one hollow tube.

3. The spike puller according to claim 1, which further comprises a guiding portion having a length L.sub.FA, said hollow tube having a length L.sub.H, and said lengths having a length ratio of: 0.2≤L.sub.FA/L.sub.H≤1.0.

4. The spike puller according to claim 1, which further comprises a guiding portion having an area A.sub.FA, said hollow tube having an area A.sub.H, and said areas having an area ratio of: 0.2≤A.sub.FA/A.sub.H≤1.0.

5. The spike puller according to claim 1, which further comprises at least one guiding element disposed between said housing and said hollow tube.

6. The spike puller according to claim 5, which further comprises a guiding portion having a length L.sub.FA, said guiding element having a length L.sub.FE, and said lengths having a length ratio of: 0.02≤L.sub.FE/L.sub.FA≤1.0.

7. The spike puller according to claim 5, which further comprises a guiding portion having an area A.sub.FA, said guiding element having an area A.sub.FE, and said areas having an area ratio of: 0.02≤A.sub.FE/A.sub.FA≤1.0.

8. The spike puller according to claim 1, wherein said linear displacement unit includes a mounting flange disposed at said hollow tube.

9. The spike puller according to claim 1, wherein said linear displacement unit includes a threaded spindle.

10. The spike puller according to claim 8, wherein said hollow tube has an undercut encompassing said mounting flange in the displacement direction.

11. The spike puller according to claim 1, which further comprises a claw fastening element fastening said claw unit at said hollow tube.

12. The spike puller according to claim 1, wherein said claw unit has two claws for engaging a railroad spike, said two claws being configured to swived relative to one another.

13. The spike puller according to claim 1, which further comprises a drive unit, and a receiving retainer for receiving said drive unit.

14. The spike puller according to claim 13, wherein said receiving retainer has a handhold for holding the spike puller.

15. The spike puller according to claim 1, wherein: said housing has an upper housing portion and a lower housing portion; said linear displacement unit includes a threaded spindle; at least one bearing is disposed at said upper housing portion for bearing said threaded spindle; and said hollow tube is guided in said lower housing portion.

16. A method for pulling a railroad spike of a track, the method comprising: providing a spike puller for pulling a railroad spike of a track, the spike puller including: a housing, a linear displacement unit mounted at the housing, the linear displacement unit including a hollow tube guided in the housing, and a claw unit for engaging a railroad spike, the claw unit being displaceable by the linear displacement unit in a linear manner relative to the housing in a displacement direction; positioning the spike puller above the railroad spike and engaging the claw unit around the railroad spike; and driving the linear displacement unit, causing the hollow tube to be linearly displaced and guided within the housing and the railroad spike to be pulled out of the track.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0048] FIG. 1 is a diagrammatic, perspective view of a spike puller according to a first embodiment of the invention;

[0049] FIG. 2 is a longitudinal-sectional view of the spike puller taken along a section line II-II of FIG. 1, in the direction of the arrows, the section showing a linear displacement unit and a claw unit in an end position;

[0050] FIG. 3 is a longitudinal-sectional view of the spike puller similar to the view according to FIG. 2, the section showing the linear displacement unit and the claw unit in an engagement position;

[0051] FIG. 4 is a perspective view of a hollow tube and a claw fastening element according to the first embodiment; and

[0052] FIG. 5 is an enlarged, fragmentary, sectional view of a spike puller according to a second embodiment.

DETAILED DESCRIPTION OF THE INVENTION

[0053] Referring now in detail to FIGS. 1 to 4 of the drawings as a whole, there is seen a first exemplary embodiment described below. FIG. 1 shows a spike puller 1 for pulling a railroad spike 5 from a track. The railroad spike 5 can be seen in particular in FIG. 2. The track is not shown in the figures for reasons of clarity.

[0054] The spike puller 1 includes a housing 2 and a receiving retainer 15 for receiving a drive unit 16. The drive unit 16 is configured as a cordless screwdriver. The receiving retainer 15 is disposed at an upper housing portion 22 of the housing 2 by using fastening elements 21a. The receiving retainer 15 is hollow-cylindrical in shape and forms a receiving space 24 for receiving the cordless screwdriver. On the side of the receiving retainer 15 opposite the upper housing portion 22, the receiving retainer 15 has a fixing flange 25, through the use of which the cordless screwdriver can be at least partially fixed. In the illustrated embodiment, the fixing flange 25 has a fixing element 26 through the use of which the cordless screwdriver can be reversibly fixed within the receiving space 24 and thus to the receiving retainer 15 itself.

[0055] In addition, the receiving retainer 15 has a handhold 17. The handhold 17 forms a holding device 27 with a grip region 28 of the cordless screwdriver, through the use of which an operator can grip and hold the spike puller 1 when pulling the railroad spike 5. In the illustrated embodiment, the grip region 28 and the handhold 17 lie on one axis and thus vertically and horizontally in one plane, whereby the holding device 27 is T-shaped.

[0056] In addition to the upper housing portion 22, the housing 2 has a lower housing portion 23. The upper housing portion 22 and the lower housing portion 23 are connected to each other through fastening elements 21b. In the illustrated embodiment, the lower housing portion 23 has a square cross-section.

[0057] A carrying handle 18 for carrying the spike puller 1 is disposed at the lower housing portion 23 of the housing 2. The carrying handle 18 is fastened through two clamps 19 spaced apart from each other. The two clamps 19 are each clamped to the housing 2 in a releasable manner through clamping elements 20 on a side of the housing 2 opposing the carrying handle 18.

[0058] A protective cap 29 is disposed at an end of the lower housing portion 23 facing the track, which protects the housing 2 from damage. In the illustrated embodiment, the protective cap 29 is disposed at the lower housing portion 23 by using fastening elements 21c.

[0059] The spike puller 1 includes a linear displacement unit 3 and a claw unit 4. The linear displacement unit 3 serves to displace the claw unit 4 in a displacement direction R.sub.1 and in an opposite counter-displacement direction R.sub.2. The linear displacement unit 3 and the claw unit 4 can be seen in particular in FIGS. 2 and 3. FIG. 2 shows the linear displacement unit 3 in an end position P.sub.2, while the linear displacement unit 3 in FIG. 3 is shown in an engagement position P.sub.1. The engagement position P.sub.1 and the end position P.sub.2 define a maximum stroke height H.sub.max.

[0060] The linear displacement unit 3 includes a threaded spindle 10, a bearing 31, a mounting flange 9 and a hollow tube 6. The threaded spindle 10 is disposed and mounted in the upper housing portion 22 by the bearing 31, the upper housing portion 22 forming a bearing housing 32 in which the bearing 31 is disposed. The threaded spindle 10 extends through the bearing 31, and thus through the bearing housing 32, into the receiving space 24. A force transmission element 41 is disposed at one end of the threaded spindle 10 which extends into the receiving space 24. When the cordless screwdriver is inserted into the receiving space 24, it can be operatively connected to the force transmission element 41. As a result, the threaded spindle 10 can be driven in rotation when the cordless screwdriver is actuated.

[0061] The mounting flange 9 is disposed inside the hollow tube 6. The mounting flange 9 is constructed as a spindle nut with a square cross-section and has an internal thread which engages in the external thread of the threaded spindle 10. In order to prevent the mounting flange 9 from unscrewing from the threaded spindle 10, the latter has a stop element 34 at a lower end opposing the upper end.

[0062] The hollow tube 6 also has a square cross-section and is disposed at a circumferential outer side of the mounting flange 9 through fastening elements 21d. Since the fastening elements 21d are disposed vertically to the displacement direction R.sub.1 and thus also vertically to a force flow resulting from the pulling of the railroad spike 5, they are loaded in shear in the illustrated embodiment.

[0063] The cross-section of the hollow tube 6 is configured in such a way that it is not rotatable within the lower housing portion 23 relative thereto. In other words, the hollow tube 6 has a maximum cross-section which is greater than or equal to a minimum cross-section of the lower housing portion 23. As a result, the mounting flange 9 and the hollow tube 6 are displaceable in a guided manner within the lower housing portion 23 in the displacement direction R1 when the threaded spindle 10 is rotatably driven.

[0064] The hollow tube 6 has a plurality of guiding elements 8, which are attached to the hollow tube 6 by using a tongue-and-groove connection. For this purpose, the hollow tube 6 has grooves into which the tongues of the individual guiding elements 8 can be reversibly inserted.

[0065] The claw unit 4 serves for engaging a railroad spike 5 and is disposed at the hollow tube 6 through a claw fastening element 12. The claw fastening element 12 has a width B.sub.GB which is smaller than a width B.sub.H of the hollow tube 6. In the illustrated embodiment, the claw fastening element 12 is V-Shaped and welded to an inner surface of the hollow tube 6. The claw unit 4 has a first gripper 13 and a second gripper 14, the grippers being rotatably connected to each other through a rotary pin 37.

[0066] Each of the two grippers or claws 13 and 14 has an engaging portion 39. The respective engaging portions 39 are the portions of the claws 13 and 14 at which the latter engage the railroad spike 5.

[0067] Each of the two claws 13 and 14 also has a swivel portion 40. The respective swivel portions 40 are the portions of the claws 13 and 14 at which they are disposed at the claw fastening element 12 through a swivel pin 38. For fastening the claws 13 and 14, the claw fastening element 12 has a receiving bore 36 into which the pivot pin 38 can be reversibly inserted or plugged. The respective swivel portions 40 each have a curved swivel groove 33 in which the swivel pin 38 is guided in a pivotable manner. Through the use of the curved swivel grooves 33, the claws 13 and 14 are mounted on the swivel pin 38 so as to be pivotable relative to one another, as a result of which, when the swivel pin 38 is displaced within the curved swivel grooves 33, the two claws 13 and 14 can be rotated about the rotary pin 37.

[0068] The claw unit 4 can be displaced between the engagement position P.sub.1 and the end position P.sub.2 by linear displacement of the linear displacement unit 3 in the displacement direction R.sub.1. The engagement position P.sub.1 is the position in which the mounting flange 9 abuts the stopper 34 in a lowermost position and the claw unit 4 engages the railroad spike 5. The engagement position can be seen in FIG. 3. The end position P.sub.2 is the position in which the mounting flange 9 abuts a stop 30 of the upper housing portion 22 in an uppermost position. The end position can be seen in FIG. 2.

[0069] FIG. 4 shows the hollow tube 6 as well as guiding elements 8 disposed thereat and the claw fastening element 12. The guiding elements 8 serve to guide the hollow tube 6 within the lower housing portion 23. The hollow tube 6 has a length L.sub.H in the displacement direction R.sub.1. The hollow tube 6 forms a guiding portion 7. The guiding portion 7 is the maximum distance between two guided points at which the hollow tube 6, and thus the linear displacement unit 3, is guided within the lower housing portion 23. The guiding portion 7 has a length L.sub.FA in the displacement direction R.sub.1. For example, for a length ratio L.sub.FA/L.sub.H, 0.2≤L.sub.FA/L.sub.H≤1.0, in particular 0.3≤L.sub.FA/L.sub.H≤0.9, in particular 0.4≤L.sub.FA/L.sub.H≤0.8. In addition, the guiding portion 7 has an area A.sub.FA and the hollow tube 6 has an area A.sub.H, where an area ratio A.sub.FA/A.sub.H is for example: 0.2≤A.sub.FA/A.sub.H≤1.0, in particular 0.3≤A.sub.FA/A.sub.H≤0.9, in particular 0.4≤A.sub.FA/A.sub.H≤0.8. The area A.sub.H is defined by the length L.sub.H and the width B.sub.H of the hollow tube 6. The area A.sub.FA is defined by the length L.sub.FA and a width B.sub.FA of the guiding portion 7.

[0070] Each individual guiding element 8 has a length L.sub.FE and a width B.sub.FE, through which an area A.sub.FE is defined for each guiding element 8. For a length ratio L.sub.FE/L.sub.FA, for example: 0.02≤L.sub.FE/L.sub.FA≤1.0, in particular 0.1≤L.sub.FE/L.sub.FA≤0.9, in particular 0.2≤L.sub.FE/L.sub.FA≤0.8. For an area ratio A.sub.FE/A.sub.FA, for example: 0.02≤A.sub.FE/A.sub.FA≤1.0, in particular 0.1≤A.sub.FE/A.sub.FA≤0.9, in particular 0.2≤A.sub.FE/A.sub.FA≤0.8. In this case, the area A.sub.FE is the guiding surface on which the hollow tube 6 is guided.

[0071] With reference to FIG. 5, a second embodiment of the spike puller 1 is described. Constructively identical components have the same reference numeral as in the previous FIGS. 1 to 4. In the second embodiment, the hollow tube 6 has an annular undercut 11 which forms a stop and abuts against a bearing surface 35 of the mounting flange 9. In the illustrated embodiment, the mounting flange 9 is disposed completely inside the hollow tube 6. The undercut 11 is reversibly fastened to the mounting flange 9 by using fastening elements 21e. In the illustrated embodiment, the fastening elements 21e are disposed in the direction of the force flow. Due to the undercut 11, the fastening elements 21e are in particular no longer loaded in tension and/or in shear. With regard to the further structure, reference is made to the preceding embodiment.

[0072] The method for pulling a railroad spike 5 from a track is as follows:

[0073] The spike puller 1 is positioned by the user above the railroad spike 5 to be pulled. The claw unit 4 is in the lower engaging position, with the claws 13 and 14 in the open position and gripping around the railroad spike 5. By actuating the drive unit 16 or the cordless screwdriver, the threaded spindle 10 is rotationally driven, whereby the mounting flange 9, the hollow tube 6 and the claw unit 4 are displaced upwards in the displacement direction R.sub.1 within the housing 2. Due to the displacement, the swivel pin 38 disposed on the claw fastening element 12 causes the claws 13 and 14 to rotate about the rotary pin 37 as a result of the curved swivel grooves 33. The rotation results in a closing movement of the claws 13 and 14, causing the engaging portions 39 to engage the railroad spike 5. Subsequently, the claw unit 4 is displaced in the displacement direction R1 by using the linear displacement unit 3 and by guiding the hollow tube 6 inside the housing 2 to the end position as far as the stop 30, whereby the railroad spike 5 is pulled out of the track.

[0074] For the transfer to the engagement position, the linear displacement unit 3 or the hollow tube 6 is displaced in the counter-displacement direction R.sub.2. The claws 13 and 14 are spread again, for example, by a preloaded spring element. After removing the pulled railroad spike 5 from the claw unit 4, the spike puller 1 is ready to pull a railroad spike 5 again.