Patent GB-670154-A (GB)
Title: File cutting machine
IPC: B24B3/60
Filed: 1949-12-21
Abstract: 670,154. Grinding files. FOUQUET, E. Dec. 21, 1949 [Sept. 5, 1949], No. 32764/49. Class 60. A machine for cutting files by grinding comprises a file-cutting grinder 67, Fig. 3, a crush roller 186 for cutting and renewing the working profile thereof, a maintenance grinder 124 for cutting and maintaining the accuracy of the profile of the crush roller, a carriage 28 in which the grinders and crush roller are detachably mounted in parallel relation and the crush roller is arranged for movement into operative relation with either grinder, and a file-supporting carriage 4 disposed beneath the carriage 28 and displaceable perpendicularly to the axes of the tools; the carriage 28 is mounted for pivotal movement about an axis 25 parallel to the axes of the tools so that it can be swung together with the tools to and from the carriage 4. The carriage 4 is reciprocated on guides 2, 3, Fig. 6, by a rack 19 and pinion 18 actuated by a reversible motor and is provided with an electromagnetic plate 7 on which the files 8 are supported. The pivotal axis 25 of the carriage 28 is a shaft which is journalled in the main frame 1 and rotated to swing the carriage to and from operative positions by pivotally-mounted hydraulic motors 46, Fig. 2; in its lowered position the carriage is adjusted by screw jacks 34 actuated by hand-operated worm gearing. The grinder 67, Fig. 6, is mounted between flanges 72, 73 on a hub 68 which is splined on the stepped part of a spindle 69 and secured thereto by a nut 74 on a threaded part 75 of the spindle. The spindle is journalled at one end in a bearing 108 in one side 3 of the carriage and its opposite extended end carries a sleeve 7 and driving pulley 79, The sleeve 77 is in screw-threaded engagement at 107 with a support 88 fixed to the corresponding side 64 .of the carriage and is maintained against play therein by spring- pressed pistons 89. An hydraulic motor 93, Figs. 6 and 11, acts upon a lever 86 carried by the sleeve whereby the latter may be rotated to cause axial movement of the spindle 69 and grinder 67. A projection 106, Fig. 11, on the lever 86 co-operates with adjustable abutments 99, 101 on the support 88 to control the limits of this movement. The grinder 124 is mounted in substantially the same manner as the grinder 67, but the lever 86 and hydraulic motor 93 are replaced by a hand-operated sleeve for rotating the screwthreaded sleeve and moving the grinder axially. The crushroller 186, Fig. 8, is mounted between the grinders 67, 124 on a slide 155, 162 movable in dovetail guides on the roof of the carriage 28 by screw-and-nut mechanism 165, 166, Fig. 3, actuated by hand-operated gearing. The roller is mounted on ball bearings 187, 188 on an axle 192 which is rotatably and eccentrically mounted at 193, 194 in the depending arms 176, 177 of a carrier 126 bolted to the slide 155. To permit orientation of the roller in the direction of whichever grinder it is. to operate upon, a clutch face 195 on the end of the bearing 193 co-operates with a clutch face 196 on the end of a sleeve 197 rotatable and axially movable in the side 64 of the carriage 28; the roller may be locked against axial play by screwing up a nut 207 on the extended end 208 of the axle 192. The bearing 194 is rotatable in a sleeve 181 having a clutch face for co-operation with a clutch face 236 on a sleeve 224 which is rotatable and axially-movable in the side wall 63 of the carriage; with these clutch faces engaged by sliding the sleeve 224 axially by a lever 226, the roller 186 is rotated from a motor 213 through gearing 217-223 and a pinion 184 on the sleeve 181 meshing with an internal gear 185 on the roller. For grinding files, the carriage 4 with the files 8 thereon, is reciprocated in contact with the grinder 67 which is rotated by its drive. pulley 79, Fig. 6, and, between the strokes of the carriage 4, the motor 93 is energised automatically' to feed the grinder axially a distance controlled by the position of the projection 106 in relation to the adjustable abutments 99, 101. This distance may correspond, for example, to half the pitch of the grinder teeth whereby the file teeth are cut with a pitch half that of the grinder. The machine may also be used for sharpening files, and, during both the grinding and sharpening processes, the roller 186 may be used to dress the grinder 67, and the grinder 124 to restore the roller to its correct shape; when restoring the roller 186 by the grinder 124, the latter is moved axially to a controlled extent by its hand-operated sleeve. The following steps are involved in preparing the machine for grinding: (1) Each grinder 67, 124 is shaped to a profile corresponding to the general profile of the files to be cut by a separate diamond device comprising a carrier 251, Fig. 3, movable transversely of the carriage 28 in a dovetailed guide 249 by a screw 252; a diamond 244 is adjustable axially in a sleeve 257 pressed by a spring 256 against a transverse guide 262 which controls the axial movement of the diamond as the carrier is traversed by the screw. (2) The crush roller 186 is shaped to corresponding form by swinging it about its axis into close proximity to the grinder 124, rotating both the roller and grinder by their respective motors, and feeding the roller into engagement with the grinder by the gearing 165, 166. (3) The profiled roller is dismantled, cut to provide file teeth in a suitable machine, and again installed. (4) This roller is used to shape the grinder 124 by a crush-rolling operation, and then, replaced by a contoured roller which is shaped, in turn, by the grinder 124 and used in a crush-rolling operation to shape the grinder 67. In both these crush-rolling operations, the grinder is driven from the rotated crush roller which is freed for axial movement by releasing the nut 207. In some cases, the teeth may be formed on the two grinders 67, 124 by the same crush roller. When using the grinder 124 to groove the crush roller, the grinder may be fed axially between successive cuts by its hand-operated sleeve to cut grooves of a pitch which is a sub-multiple of that of the grinder teeth. To facilitate dismantling of the grinders and crush roller, a cradle 110, Fig. 2, having upstanding portions for supporting these members is bolted to the carriage 4, and the carriage 28 is lowered so as to position the grinders and roller on to the supports. The nut 74, Fig. 6, is then held stationary by pushing inwardly through the bearing 108 a spring-controlled member so that its ends engage holes 121 in the nut. After raising the carriage 28, the motor 93 is uncoupled from the lever 86, and the latter is connected by a pin with the flanged end of the pulley 79, which is then driven by its belt to unscrew the nut 74 from the spindle 69. The endwise withdrawal of the spindle 69 and pulley 79 is effected by an extractor 139, Figs. 6 and 11, which is slidable on a guide 140 and comprises a cradle portion 143À to support the pulley and a hub to fit over the end of the spindle. The extractor is moved into this position by a rack 136 and pinion 135, the hub is screwed on the threaded end 84 of the spindle by a nut, and the assembly can then be withdrawn by the outward movement of the extractor. A similar arrangement is provided for the grinder 124, and switch means operated by the extractors for the two grinders prevents actuation of the carriage-operating motors 46 except when the extractors are positioned on the spindles.