GB1569053A

GB1569053A - Apparatus for removing flash from weld joints

Info

Publication number: GB1569053A
Application number: GB156278A
Authority: GB
Original assignee: Institut Elektrosvarki Imeni E O Patona Akademii Nauk Ukrainskoi Ssr
Current assignee: Institut Elektrosvarki Imeni E O Patona Akademii Nauk Ukrainskoi Ssr
Priority date: 1978-01-14
Filing date: 1978-01-14
Publication date: 1980-06-11

Description

(54) IMPROVEMENTS IN OR RELATING TO APPARATUS FOR REMOVING FLASH FROM WELD JOINTS (71) We, INSTITUT ELEKTROSVARKI IMENI E.O. PATONA AKADEMII NAUK UKRAiNsKOI SSR a Corporation organised and existing under the laws of the U.S.S.R., of Ulitsa Bozhenko 11, Kiev, Union of Soviet Socialist Republics, do hereby declare the invention, for which we pray that a patent may be granted us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to apparatus for removing flash from resistance butt-weld joints in rails.

According to the invention, there is provided apparatus for removing flash from resistance butt-weld joints in rails which have a longitudinal plane of symmetry, the apparatus comprising a claw clamp with two grips arranged to engage respective sides of a rail to clamp the rail during use of the apparatus, a clamping cylinder kinematically linked with the grips to effect operation of the claw clamp, the grips carrying a common upper cutter and respective side cutters, and the cutters being so mounted that in use of the apparatus with the claw clamp closed on a rail, the cutting edges of the cutters form an outline encompassing the cross-sectional perimeter of the rail with the shape of the cutting edge of the upper cutter conforming to that of the top portion of the rail head and the shapes of the cutting edges of the side cutters conforming to that of the side surfaces and foot of the rail, each side cutter being pivotally connected to the upper cutter and to its associated grip with its connection to the grip being such as to enable the cutter to be displaced parallel to the axis of symmetry of said outline, and a clearance take-up mechanism kinematically linked with the clamping cylinder and the upper cutter such that operation of the clamping cylinder to close the grips on a rail also serves to displace the upper and side cutters along the axis of symmetry of said outline to engage the side cutters with the underside of the rail foot.

Apparatus embodying the invention and for removing flash from resistance butt-weld or nuts in rails, will now be particularly described by way of example with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a view taken on line I-I of Figure 7 and shows the apparatus in section; Figure 2 is a section on line II-II of Figure 1; Figure 3 is an enlarged view of upper and side cutters of the apparatus in the closed and open positions; Figure 4 is a kinematic diagram of a preferred embodiment of a clearance take-up mechanism of the apparatus; Figures 5 and 6 show kinematic diagrams of alternative embodiments of the clearance take-up mechanism and relate respectively to where the mechanism employs a clamping cylinder with a non-adjustable stroke piston and to where the mechanism employs a clamping cylinder with an adjustable stroke piston; and Figure 7 is a side elevation of a claw-type resistance butt welding machine incorporating the apparatus for removing flash.

As shown in Figure 1, the apparatus for removing flash from resistance butt-weld joints in rails comprises a base 1 in the form of a claw clamp comprising two grips 2 and 3 mounted for counter rotation relative to each other on a common fixed trunnion 4. Each grip has an upper and a lower portion, the lower portions of the grips 2 and 3 terminating in jaws 5 and 6 for embracing a rail 49. The common fixed trunnion 4 is hollow and is arranged along the plane of symmetry of the claw clamp, this plane being coincident with the longitudinal plane of symmetry of the rail 49 clamped in the jaws 5 and 6.

Mounted on the trunnion 4 for rotation thereabout is a clamping cylinder 7 comprising a housing 8 (Fig. 2), a piston 9 movably mounted in the housing 8, and a rod 10 fixedly attached to the piston 9 and carrying a crossbeam 11 secured thereon.

The crossbeam 11 is connected with the upper ends of the claw clamp grips 2 and 3 by drag links 12 and 13 (Fig. 1). A thrust piece 14 (Figs. 1,2) whose function will be explained hereinafter, is fixed by fastening screws 16 to the crossbeam 11. The thrust piece 14 is vertically adjustable within the length of slots 15 (Fig. 1) through which the fastening screws 16 are fitted.

Each grip 2 and 3 carries a respective side cutter 17 and 18 (Figs. 1,3) and these side cutters are coupled at points 19 and 20 with an upper cutter 21 by means of hinge joints which will be referred to as the first hinge joints. The cutting edge of the upper cutter 21 is shaped in conformity with the shape of the top portion of the rail head. The cutting edges of the side cutters 17 and 18 are shaped in conformity with the shape of the side surfaces and foot underside of the rail.

The side cutters 17 and 18 are connected with the grips 2 and 3 by means of hinge pins 22 and 23 of second hinge joints. The hinge pins 22 and 23 are fixedly secured to the grips 2 and 3 and locate in slots 24 and 25 in the side cutters 17 and 18 for displacement along the slots. The width of the slots 24 and 25 corresponds to the diameter of the hinge pins 22 and 23. The slots 24 and 25 extend parallel to the axis of symmetry of the closed outline formed by the cutting edges of the upper cutter 21 and side cutters 17 and 18 when the latter are closed around the rail 49.

The apparatus further comprises a clearance (take-up mechanism 26 (Fig. 1) which provides for the displacement of the cutters along their axis of symmetry until the cutting edges engage the rail foot. The clearance take-up mechanism 26 includes a pull member 27 (Figs. 1,2,4) coupled with the upper cutter 21, a lever 28 (Figs. 2,4) interacting with the pull member 27, and a pusher 29 coupled with the lever 28 and acted upon by the thrust piece 14 of the crossbeam 11.

In the preferred embodiment of the appar atus, illustrated in Figs. 1,2,4, the pull member 27 is compound and comprises a rod 30 (Figs. 1,2), a crossbar 31 perpendicular to the rod 30, and two side members 32 (Fig. 1) fixedly coupled with the crossbar 31 and attached to the upper cutter 21 by screws 33. The crossbar 31, side members 32 and upper cutter 21 form a frame embracing the fixed trunnion 4 and the side members 32 touch the trunnion at contact points M and N.

Thus the fixed trunnion 4 serves as a guide for the pull rod 27 when the latter effects translatory motion. In addition, such an arrangement enables the pull rod 27 to rotate with respect to the trunnion 4 when the clamping cylinder 7 rotates around the same trunnion.

The lever 28 (Fig. 2) has a fixed fulcrum pin 34 fitted in holes in a bracket 35 fixedly coupled with the housing 8 of the clamping cylinder 7. A first arm 36 of the lever 28 contacts the pusher 29. A second arm 37 of the lever 38 (disposed on the opposite side of the fixed fulcrum pin 34 to the first arm 36) is forked (Figs. 2,4) and has a slit 38 between the fork arms for receiving the rod 30 of the pull member 27.

A compression spring 39 (Figs. 1,2,4) is fitted over the end of the rod 30 extending up through the slit 38 and the spring 39 is retained at its upper end by a washer 40 and a nut 41 screwed onto the threaded end of the rod 30.

The pusher 29 of the clearance take-up mechanism 26 takes the form of two identical pins 42 (Fig. 1) mounted parallel to each other and arranged to slide in guide openings provided in the cover of the housing 8 of the clamping cylinder 7. The pins 42 are mounted so that their top ends project above said cover for a length smaller than the length of the stroke of the piston 9 so that the pusher 29 is acted upon by the thrust piece 14 only over part of the stroke of the piston 9. This arrangement together with the provision of the compression spring 39, compensates for the difference between the actual stroke length of the piston 9 and the length of stroke required to displace the side cutters into engagement with the rail foot underside. The bottom ends of the pins 42 of the pusher 29 push against the first arm 36 of the lever 28.

Figs. 5 and 6 are kinematic diagrams of two further embodiments of the clearance take-up mechanism 26, functionally similar elements being denoted by the same reference numerals as in Figs. 1 to 4 but with single or double primes respectively.

The embodiment of the clearance take-up mechanism 26 illustrated in Fig. 5 differs from the above-described one in that the pusher 291 is fixed to the crossbeam 11 and is hinged at point 43 to the first arm 36 of the lever 28. The difference between the actual length of stroke of the piston 9 and the length of stroke required to displace the side cutters 17 and 18 into engagement with the rail foot underside is in this case compensated for by the compression spring 39 alone.

The embodiment of the clearance take-up mechanism 26 illustrated in Fig. 6 relates to cases where the clamping cylinder has an adjustable stroke piston 9.

The adjustment of stroke of the piston 9 is effected by any suitable known means such as by an adjustable stop (not shown) mounted on the clamping cylinder 7 and interacting with the crossbeam 11. In this case the pull member 2711 is formed as a drag link one end of which is connected with the upper cutter 21 by means of a hinge pin 44, whereas its other end is connected with the appropriately shaped second arm 3711 of the lever 281l by means of a hinge pin 45.

The apparatus for removing flash from resistance butt-weld joints in rails as described above may be used either separately or, which is preferable, as a component of a claw-type machine for resistance butt welding of rails (Fig. 7). As is known such machines generally comprise a stationary clamp for gripping one rail and a movable clamp for gripping a second rail, the movable clamp being displaceable toward the stationary one in the longitudinal direction of the rails to bring the ends of the rails into abutment for welding.

In the case where the present apparatus is incorporated in a welding machine, its base 1 forms the movable clamp of the machine whose stationary clamp is part of the machine's base 46 (see Fig. 7) and takes the form of a claw clamp similar to the claw clamp of the base 1 and having the fixed trunnion 4 in common therewith.

Fixed to the machine base 1 are upset actuating cylinders 47 (Figs. 1,7) whose rods are fixed to the stationary base 46.

The apparatus incorporated into the machine for resistance butt welding of rails functions as follows.

Rails 48 and 49 (Fig. 7) to be welded together are clamped in the jaws 5 and 6 of the claw clamp of the base 1 (Fig. 1) and in similar jaws of the stationary base 46 (Fig. 7).

To effect this clamping, working fluid fed into the upper chamber of the clamping cylinder 7. As the piston 9 (Fig. 2) with the rod 10 and the crossbeam 11 attached thereto moves down, the drag links 12 and 13 turn upwards relative to their hinge pins mounted on the crossbeam 11 and tend to a horizontal position. As a result, the upper ends of the grips 2 and 3 move apart, turning about the common fixed trunnion 4; their lower ends with the jaws 5 and 6 correspondingly move towards each other until they engage the web of the rail 49. On engaging the rail web, the jaws 5 and 6 self-align thereto, this being possible due to the freedom of the grips 2 and 3 to swing, together with the clamping cylinder 7, relative to the trunnion 4. The jaws of the stationary base 46 clamp the rail 48 in a similar manner.

As the jaws 5 and 6 move towards each other during clamping, the side cutters 17 and 18 (which are coupled with the jaws by the hinge pins 22 and 23 and are also hinged with the upper cutter 21 which functions as a tie rod) rotate from an initial position shown in phantom in Fig. 3 towards each other about the points 19 and 20. At the moment when the rail 49 becomes freely resting by the bottom portion of its head on the jaws 5 and 6, the side cutters 17 and 18 start embracing the rail 49 around its cross-sectional perimeter.

The cutting edges of the side cutters 17 and 18 and upper cutter 21 are shaped so that when the edges close around the rail 49, a clearance of about 1-5 to 2 mm is left between the edges and the surface of the rail along the entire perimeter; this eliminates the risk of jamming the rail 49 between said cutting edges.

In the preferred embodiment of the apparatus (Figs. 2,4), towards the end of the stroke of the piston 9 of the clamping cylinder 7 the thrust piece 14 of the crossbeam 11 depresses the pins 42 of the pusher 29 of the clearance take-up mechanism 26. The pins 42 move down, forcing down the first arm 36 of the lever 28 which is thereby turned about the fulcrum pin 34. The second arm 37 of the lever 28 rises and urges the pull member 27 upwards together with the upper cutter 21 suspended therefrom on the screws 33. The side cutters 17 and 18 move upwards together with the upper cutter 21, the walls of the slots 24 and 25 in the side cutters (which walls are parallel to the axis of symmetry of the rail cross-section and vertically disposed at this moment) freely slide relative to the hinge pins 22 and 23 fixedly attached to the grips 2 and 3.

The stiffness of the spring 39 is selected such that the spring is not compressed when there is no resistance to the displacement of the pull member 27 together with the cutters.

If the piston 9 continues to travel after the lower cutting edges of the side cutters 17 and 18 have engaged the underside of the foot of the rail 49, then the lever 28 as it continues to turn under the action of the pusher 29, compresses the spring 39; the presence of the spring 39 thus makes it unnecessary to exactly match the travel of the pusher 29 acted upon by the thrust piece 14 to the required displacement of the cutters.

The entire length of the stroke of the piston 9 can be employed for the displacement of the cutters, as in the embodiment of the clearance take-up mechanism illustrated in Fig. 5, where the pusher 29 is fixed to the crossbeam 11. The compressability of the spring 39 is in this case correspondingly higher than in the above-described embodiment shown in Figs. 2,4.

In the embodiment of the clearance take-up mechanism illustrated in Fig. 6, the stroke of the piston 9 should be adjusted so that, with the selected ratio of the lengths of the arms of the lever 2811, it produces a vertical displacement of the cutters corresponding to the width of the clearance between the underside of the foot of the rail 49 and the lower cutting edges of the side cutters 17 and 18.

The above-described action of the clearance take-up mechanism 26 has the result that the side cutters 17 and 18 jointly with the upper cutter 21 embrace the rail 49 around its entire cross-sectional perimeter with a predetermined clearance being produced at the sides of the web and along the head of the rail while the cutting edges of the side cutters 17 and 18 intimately mate the underside of the foot of the rail 49 as shown in Fig. 3.

Next, heating means of the welding machine are switched on and the actuating cylinders 47 shift the base 1 together with the rail 49 clamped therein, towards the stationary base 46 to effect butt welding of the rails 48 and 49.

The pressure in the clamping cylinder 7 is then relieved, with the result that the end of the rail 49 clamped by the claw clamp of the base 1 is released from the jaws 5 and 6 (Fig. 1). However, the jaws 5 and 6, as well as the side cutters 17 and 18, do not open completely, but only move away from the rail 49 by a distance enabling them to slide along the rail 49. The base 1 is thereafter shifted with respect to the welded rail towards the stationary base 46 by an additional stroke of the upset actuating cylinders 47. During the latter shift, the upper cutter 21 and the side cutters 17 and 18 cut off flash over the entire cross-sectional perimeter of the welded rail, the flash on the underside of the rail foot being cut off with almost zero allowance.

After flash has been cut off, working fluid is fed into the lower chamber of the clamping cylinder 7 (Fig. 2) causing the piston 9 together with the rod 10 and the crossbeam 11 to ascend so that the pusher 29 is either shifted upwards by the spring 39 (Figs. 2,4) or carried up by the crossbeam 11 (Figs. 5 and 6) connected with the pusher. At the same time, the lever 28, 281 or 2811 (respectively Fig. 4, 5 or 6), turns and forces down the pull member 27 together with the upper cutter 21 and the side cutters 17 and 18.

The upper ends of the grips 2 and 3 move toward each other under the action of the drag links 12 and 13, while the lower ends of the grips move apart and open the side cutters 17 and 18 (Fig. 3, phantom lines), thus completely releasing the welded rail.

The remainder of flash on the side and top surfaces of the rail is removed by subsequent machining of the rail. The rail foot underside requires no additional machining.

When the apparatus for removing flash is employed independently of a machine for resistance butt welding of rails, the clamping previously effected by the machine's base 46 and the shifting of the welded rail with respect to the cutters, is carried out by means of separate actuators.

The described apparatus enables the flash to be removed from the rail foot underside with substantially no remainder left and thus makes it possible to cut down the labour and time spent for this operation due to eliminating a subsequent manual trimming of flash remainder. When the above-described apparatus is employed as a component of a rail welding machine, its manufacturing cost is reduced to the cost of the cutters and their associated mechanism; furthermore, the flash cut-off operation requires in this case a minimum power consumption since the metal being removed has not enough time to cool down after welding.

WHAT WE CLAIM IS: 1. Apparatus for removing flash from resistance butt-weld joints in rails which have a longitudinal plane of symmetry, the apparatus comprising a claw clamp with two grips arranged to engage respective sides of a rail to clamp the rail during use of the apparatus, a clamping cylinder kinematically linked with the grips to effect operation of the claw clamp, the grips carrying a common upper cutter and respective side cutters, and the cutters being so mounted that in use of the apparatus with the claw clamp closed on a rail, the cutting edges of the cutters form an outline encompassing the cross-sectional perimeter of the rail with the shape of the cutting edge of the upper cutter conforming to that of the top portion of the rail head and the shapes of the cutting edges of the side cutters conforming to that of the side surfaces and foot of the rail, each side cutter being pivotally connected to the upper cutter and to its associated grip with its connection to the grip being such as to enable the cutter to be displaced parallel to the axis of symmetry of said outline, and a clearance take-up mechanism kinematically linked with the clamping cylinder and the upper cutter such that operation of the clamping cylinder to close the grips on a rail also serves to displace the upper and side cutters along the axis of symmetry of said outline to engage the side cutters with the underside of the rail foot.

2. Apparatus according to claim 1, wherein the clearance take-up mechanism comprises a pull member connected to the upper cutter, a pusher arranged to be acted upon by a piston rod of the cylinder, and a lever with two arms extending on respective sides of a fixed fulcrum pin, the first of the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. mechanism illustrated in Fig. 6, the stroke of the piston 9 should be adjusted so that, with the selected ratio of the lengths of the arms of the lever 2811, it produces a vertical displacement of the cutters corresponding to the width of the clearance between the underside of the foot of the rail 49 and the lower cutting edges of the side cutters 17 and 18. The above-described action of the clearance take-up mechanism 26 has the result that the side cutters 17 and 18 jointly with the upper cutter 21 embrace the rail 49 around its entire cross-sectional perimeter with a predetermined clearance being produced at the sides of the web and along the head of the rail while the cutting edges of the side cutters 17 and 18 intimately mate the underside of the foot of the rail 49 as shown in Fig. 3. Next, heating means of the welding machine are switched on and the actuating cylinders 47 shift the base 1 together with the rail 49 clamped therein, towards the stationary base 46 to effect butt welding of the rails 48 and 49. The pressure in the clamping cylinder 7 is then relieved, with the result that the end of the rail 49 clamped by the claw clamp of the base 1 is released from the jaws 5 and 6 (Fig. 1). However, the jaws 5 and 6, as well as the side cutters 17 and 18, do not open completely, but only move away from the rail 49 by a distance enabling them to slide along the rail 49. The base 1 is thereafter shifted with respect to the welded rail towards the stationary base 46 by an additional stroke of the upset actuating cylinders 47. During the latter shift, the upper cutter 21 and the side cutters 17 and 18 cut off flash over the entire cross-sectional perimeter of the welded rail, the flash on the underside of the rail foot being cut off with almost zero allowance. After flash has been cut off, working fluid is fed into the lower chamber of the clamping cylinder 7 (Fig. 2) causing the piston 9 together with the rod 10 and the crossbeam 11 to ascend so that the pusher 29 is either shifted upwards by the spring 39 (Figs. 2,4) or carried up by the crossbeam 11 (Figs. 5 and 6) connected with the pusher. At the same time, the lever 28, 281 or 2811 (respectively Fig. 4, 5 or 6), turns and forces down the pull member 27 together with the upper cutter 21 and the side cutters 17 and 18. The upper ends of the grips 2 and 3 move toward each other under the action of the drag links 12 and 13, while the lower ends of the grips move apart and open the side cutters 17 and 18 (Fig. 3, phantom lines), thus completely releasing the welded rail. The remainder of flash on the side and top surfaces of the rail is removed by subsequent machining of the rail. The rail foot underside requires no additional machining. When the apparatus for removing flash is employed independently of a machine for resistance butt welding of rails, the clamping previously effected by the machine's base 46 and the shifting of the welded rail with respect to the cutters, is carried out by means of separate actuators. The described apparatus enables the flash to be removed from the rail foot underside with substantially no remainder left and thus makes it possible to cut down the labour and time spent for this operation due to eliminating a subsequent manual trimming of flash remainder. When the above-described apparatus is employed as a component of a rail welding machine, its manufacturing cost is reduced to the cost of the cutters and their associated mechanism; furthermore, the flash cut-off operation requires in this case a minimum power consumption since the metal being removed has not enough time to cool down after welding. WHAT WE CLAIM IS:

1. Apparatus for removing flash from resistance butt-weld joints in rails which have a longitudinal plane of symmetry, the apparatus comprising a claw clamp with two grips arranged to engage respective sides of a rail to clamp the rail during use of the apparatus, a clamping cylinder kinematically linked with the grips to effect operation of the claw clamp, the grips carrying a common upper cutter and respective side cutters, and the cutters being so mounted that in use of the apparatus with the claw clamp closed on a rail, the cutting edges of the cutters form an outline encompassing the cross-sectional perimeter of the rail with the shape of the cutting edge of the upper cutter conforming to that of the top portion of the rail head and the shapes of the cutting edges of the side cutters conforming to that of the side surfaces and foot of the rail, each side cutter being pivotally connected to the upper cutter and to its associated grip with its connection to the grip being such as to enable the cutter to be displaced parallel to the axis of symmetry of said outline, and a clearance take-up mechanism kinematically linked with the clamping cylinder and the upper cutter such that operation of the clamping cylinder to close the grips on a rail also serves to displace the upper and side cutters along the axis of symmetry of said outline to engage the side cutters with the underside of the rail foot.

arms being coupled with the pusher, and the second, with the pull member.

3. Apparatus according to claim 2, wherein the second arm of the lever is forked at its free end, the pull member extending between the fork arms and being spring biased by a spring reacting against the fork arms.

4. Apparatus according to claim 3, wherein a thrust piece is fixed to the piston rod and is arranged to contact the pusher towards the end of the piston stroke.

5. Apparatus according to claim 2, wherein the piston rod of the clamping cylinder is fixedly coupled with the pusher, and the latter is pivoted to the first arm of the lever.

6. Apparatus according to claim 5, wherein the pull member is pivoted at one end to the second arm of the lever and at its other end to the upper cutter, the clamping cylinder having an adjustable stroke piston.

7. Apparatus according to any of the preceding claims, wherein each side cutter is provided with a slot parallel to the axis of symmetry of the outline formed by the cutting edges of the upper and side cutters with the claw clamp closed a pivot pin fast with the grip associated with this cutter engaging in said slot to effect the said connection therebetween.

8. Apparatus for removing flash from resistance butt-weld joints in rails, the apparatus being substantially as hereinbefore described with reference to Figures 1 to 4, and 7 of the accompanying drawings.

9. Apparatus for removing flash from resistance butt-weld joints in rails, the apparatus being substantially as hereinbefore described with reference to Figure 7 and Figures 1 to 3 as modified by Figure 5 or Figure 6 of the accompanying drawings.