GB2356370A - Drill for drilling holes in railway track - Google Patents

Abstract

A drill for drilling rails of railways or railroads and of the kind comprising a body (1) carrying drive means (3) for a tool and feed means (5) for moving the tool between a retracted position and a forward position to facilitate a drilling operation, and a jig (6) connected to the body and provided with clamping means (10,11) adapted to be detachably secured to a rail required to be drilled thereby to support the drill in position relative to the rail for the drilling operation, is fitted with an extension device (14) to enable thicker rails to be drilled, the extension device comprising two parts (15,23) connected between the jig (6) and the drill body (1) and slidable relative to one another to adjust the position of the body relative to the jig.

Description

2356370 DRILL This invention relates to drills for drilling rails and

track rigs for railway or railroad applications.

It is known to provide drills adapted specifically for use on track rails.

Such a drill (hereinafter referred to as "a drill of the kind specified") generally comprises a body carrying drive means for a tool and feed means for moving the tool between a retracted position and a forward position to facilitate a drilling operation, and mounting means connected to the body and provided with means adapted to be detachably secured to a rail required to be drilled thereby to support the drill in position relative to the rail for the drilling operation.

One form of such a drill is described and illustrated in European Patent Specification No. 644295. This drill comprises a body which supports a motor that drives a drilling tool through a reduction unit, the output shaft of said motor being substantially parallel to and spaced from. the axis of said tool, means for the translatory motion of said drilling tool with respect to said body, and means for removably fixing said body with respect to an element to be drilled. The body is substantially L-shaped, with a first limb that forms a flange for coupling to said motor and a second limb for accommodating said tool, the second limb being substantially perpendicular to the first limb, and said motor being coupled at said flange in a position located above said second limb with 2 said output shaft being superimposed on the axis of said tool so that the drill assembly assumes a substantially U-shaped configuration.

In the known forms of drill of the kind specified the means for moving the tool between its retracted and forward positions is such that the tool has a sufficiently long stroke to cater for most rail profiles. There are, however, some rail profiles in which the thickness of that part of the rail which is required to be drilled, is so great that the tool will not cut through it completely. So-called conductor/electric contact rails are a typical example of such a profile as they have an upper flange joined to a base flange by a relatively thick web in which a hole is required to be drilled to enable an electrical connector to be bolted to it.

A few special drills are available on the market which can cater for thicker rails but these drills are relatively long and cannot be used in confined spaces, for example when drilling the ftogs, of crossings. Also, the drills are relatively heavy and cannot be handled by a single user.

The object of the present invention is to overcome this problem by providing a device which enables conventional, relatively compact and lightweight drills to be readily adapted for use in drilling thicker rails.

In accordance with the invention there is provided in or for a drill of the kind specified, an extension device comprising two parts connected or connectable, respectively, to the body and the mounting means of the drill so as 3 to provide the connection between them, these parts being movable relative to one another to adjust the position of the mounting means relative to the body.

This arrangement enables a thicker rail to be drilled with a limited stroke of the tool. This is achieved by performing the drilling operation in two stages, namely a first stage in which the body is at a remote position relative to the mounting means and hence the rail whereby the drill can drill partway through the rail, and a second stage in which by relative movement of the said parts of the device the body is moved closer to the mounting means and the rail so that the drill can drill further through the rail.

The extension device provided by the invention has the advantages that it can be used with a conventional drill of the kind specified and can be designed so that it does not substantially increase the size and weight of the assembly, as would happen if the drill itself were modified to increase the stroke of the tool. The assembly can therefore be handled by one person. Also the two-stage drilling operation can be performed without disconnecting the drill from the rail and therefore the drill will remain on the same axis as it cuts through the rail. The drill can be used for normal drilling operations without the extension device fitted to it.

Preferably the extension device includes means for locking the two parts thereof in two predetermined positions.

The invention also provides a method of drilling a rail using a drill of 4 the kind specified which comprises fitting an extension device according to the invention between the body of the drill and the mounting means, securing the mounting means to the rail, with the extension device in an extended position operating the drill so that the tool drills part-way through the rail, contracting the extension device and operating the drill to cause the tool to cut right through the rail.

The invention will now be described, by way of example, with reference to the accompanying drawings in which:- FIGURE I is a side view showing one form of drill as used in the conventional manner, FIGURE 2 is a side view showing a similar form of drill fitted with a preferred embodiment of an extension device according to the invention, FIGURE 3 is a plan view, partly cut-away, corresponding to FIGURE 2, FIGURE 4 is a detailed plan view, partly in section, of the extension device, FIGURE 5 is a sectional view of the extension device taken on the line V- V of FIGURE 4, and FIGURE 6 is a sectional view corresponding to part of FIGURE 2 20 showing a modification of the arrangement illustrated in FIGURES 2 to 5.

The drill illustrated in the drawings is designed for drilling rails and track rigs in railway or railroad applications. In the example shown the drill is positioned for drilling a rail R.

The drill comprises a body I which is substantially L-shaped and has a first limb 2 supporting drive means. This drive means may be an internal combustion engine 3 as shown in the drawings, or an electric motor. The engine is located above the second limb 4 of the body so that the drill has a substantially U-shaped configuration. Projecting from the end of the second limb 4 is a spindle provided with a holder (not shown) adapted to clamp a tool such as a drill bit or milling cutter in an operative position coaxial with the spindle. The engine 3 has an output shaft (not shown) and the spindle is parallel to this shaft and drivingly connected to it by reduction gearing housed in the body 1. This gearing is coupled to the spindle by a slider mechanism which is operable by a pivoted lever 5 to move the spindle axially in a direction towards and away from the rail R without interrupting the drive to the spindle whereby the drill bit can be moved between a retracted position and an advanced position for drilling of the rail R.

The drill is provided with a jig 6 for attaching it to the rail R. This jig comprises a bridge-piece comprising two spaced parallel plates 7 joined by a crosspiece 8 which is formed with holes enabling it to be bolted to the upper face of the end of limb 4 of the body I when the drill is to be used in the 6 conventional manner as shown in FIGURE 1. The plates 7 have pivotally mounted on them two spaced plates 9 carrying a generically conical-shaped abutment 10 arranged to engage one side of the central web W of the rail R, the other side of the web W being engaged by a template I I which is bolted to the 5 end face of the limb 4 for conventional use of the drill as shown in FIGURE 1. The plates 9 are pivotable relative to the plates 7 by a screw mechanism 12 operable by a handle 13 so that the jig can be firmly clamped to the rail R with the web gripped between the template 11 and the abutment 10.

In normal use, with the drill in this position and with the engine 3 running to rotate the tool, the lever 5 is moved to advance the tool towards and into contact with the rail, whereupon continued movement of the tool causes it to drill a hole in the rail.

If the profile of the rail required to be drilled is such that the drill cannot pass completely through it within the maximum possible stroke of the drill, in accordance with the present invention and as illustrated in FIGURES 2 to 5 the drill is fitted with an extension device generally designated 14.

This extension device comprises a crosspiece 15 formed with holes enabling it to be bolted to the end face of the limb 4 of the body 1 with the template I I removed, and with a central aperture 16 for passage of the drill bit.

The crosspiece 15 has extended side portions 17 in which are formed, respectively, two bores receiving with a sliding fit two cylindrical guides 18.

7 Each guide has a flange 19 at one end and a coaxial screw-threaded bore 20 at the other end which is engaged by a bolt 21 securing a washer 22 to said end of the guide (FIGURE 4).

The guides18 also extend into bores in side portions of a second crosspiece 23 and are fixed to it by bolts (not shown) each of which is engaged in a screw-threaded aperture 24 formed in the crosspiece and is tightened into contact with a circumferential groove 25 in the associated guide. The second crosspiece 23 is formed in its upper face with holes to enable the crosspiece 8 of the jig 6 to be bolted to it (instead of to the body 1) and in its end face with holes to enable the template I I to be bolted to it (instead of to the body).

The first crosspiece 15 is therefore movable manually towards and away from the second crosspiece 23, sliding over the guides 18, between a first position in which the crosspieces are spaced from one another, and a second position in which they are in contact with one another. These positions are determined, respectively, by circumferential grooves 26a,26b formed in the guides 18, the crosspiece 15 being formed with two screw threaded bores receiving two adjustable screws 27 which are arranged, respectively, to engage in the grooves 26a when the crosspieces are in the first position and in the grooves 26b when the crosspieces are in the second position so that the crosspieces can be locked in each position. Each screw is provided with a knob 28 to enable it to be tightened into contact with the associated guide, and 8 released to permit relative movement of the crosspieces. Two stops 29 secured to the crosspiece 15 by screws are arranged to be contacted by shoulders formed on the screws to prevent the screws being turned to such an extent that they become fully disengaged from their respective screw threaded bores in the crosspiece. Movement of the crosspieces apart is limited by the crosspiece 15 coming into contact with the washers 22.

When using the drill fitted with the extension device to drill a hole in the rail R, the operation is commenced with the crosspiecesl5, 23 in the first position. The drill bit is advanced to the end of its permitted stroke but the thickness of the web W of the rail R is such that the hole thus formed in the web only extends partway through the web. To enable the remaining part of the hole to be drilled, the drill bit is first moved back to its retracted position and then the screws 27 are released by turning the knobs 28 and the crosspiece is moved up to the crosspiece 23 to the second position. As a result the drill is moved closer to the rail R so that it can then be advanced again to cut right through the web W.

The extension device can be easily and quickly fitted to the drill simply by disconnecting the jig 6 and the template 11 from the body 1, attaching the device to the body and then refitting the jig and the template by attaching them to the device.

FIGURE 6 shows a modification of the arrangement illustrated in 9 FIGURES 2 to 5 in which a template designated I V is formed integrally with the crosspiece 23' of the extension device 14' as a single component. This enables the overall length of the drill/extension assembly to be reduced, which is an advantage when drilling a rail within a physically restricted area. In this case, when the template I I is disconnected from the body of the drill, there is no need to refit it to the extension device 14'. The crosspiece 8 of the jig 6 is connected to the crosspiece 23' in the same way as in the arrangement shown in FIGURES 2 to 5.

It

Claims (1)

1. In or for a drill of the kind specified an extension device comprising two parts connected or connectable, respectively, to the body and the mounting means of"'the drill so as to provide the connection between them, these parts being movable relative to one another to adjust the position of the mounting means relative to the body.

2. An extension device as claimed in Claim I which includes means for locking the two parts thereof in two predetermined positions.

3. An extension device as claimed in Claim 1 or 2 wherein the part of the device connected or for connection to the body of the drill is mounted for sliding movement relative to the part connected or for connection to the mounting means of the drill.

4. An extension device as claimed in Claim 3 wherein the two parts comprise crosspieces one of which has fixed to it two spaced guides which are slidable in bores provided in the other crosspiece.

5. An extension device as claimed in Claims 2 and 4 wherein the guides are provided with grooves for engagement by adjustable screws for the purposes of locking the two parts in position.

6. A method of drilling a rail using a drill of the kind specified, which method comprises fitting an extension device as claimed in any one of the preceding claims between the body of the drill and the mounting means, securing the mounting means to the rail, with the extension device in an extended position operating the drill so that the tool drills part-way through the rail, contracting the extension device and operating the drill to cause the tool to cut right through the rail.

8. An extension device for a drill substantially as herein described with reference to FIGURES 2 to 5 of the accompanying drawings.

9. An extension device for a drill substantially as herein described with reference to FIGURES 2 to 6 of the accompanying drawings.