Patent GB-406251-A (GB)
Title: Improvements in hand operated screw threading machines
IPC: B23G1/32
Filed: 1932-05-13
Abstract: 406,251. Milling screws. FOUQUET, E., 112, Rue Jean Jaures, Bois-Colombes, Seine, France. May 13, 1932, No. 13802. Void [Abridged as open to inspection under Sect. 91 of the Acts, May 14, 1932]. [Class 83 (iii).] In a machine for cutting internal or external screw threads on pipes by means of a rotary milling-cutter, the body of the machine may be fixed in a vice &c. and the work rotated with a chuck therein, or the work may be secured in the vice and the machine rotated around the work and chuck. The machine comprises a body 1 carrying radially movable chuck jaws 3 for gripping the work T and rotatably mounted within a casing 12 provided with a guide 121 for the cutter slide 13. A toothed wheel 10 is secured to the chuck body and engages a pinion 35, Fig. 2, attached to a shaft 36 splined by keys 40 within a sleeve 37 carrying a gear 38 which is rotated through a reducing train 84, Fig. 1, from a pinion 80 on the cutter shaft 70 to which is keyed the hand operated wheel 78. An elongated pinion 44 on the shaft 36 rotates a lead screw 21 engaging a half nut on the slide 13 and drives a gear 49 in a housing 45 pivoted on the pinion. A gear 46 in the housing 45 is driven from the gear 49 and is engageable with any one of the gears 28 secured to the lead screw, the housing being retained in position by catches 53, 54 thereon and notched plates 51, 52 on the gear casing 18 and cover 56 respectively. The cutter head 64 is pivotally mounted on a boss 63 on the slide 13 concentrically with the shaft 36 so that the cutter 73 may be adjusted to operate on different diameters of work and locked by nuts 65, Figs. 2 and 5, on studs 67 passing through arcuate slots in the head. In operation, to cut an external thread on a long pipe T, the pipe is secured stationarily and the chuck jaws 3 are caused to grip it. A catch 58, Fig. 1, on the gear cover 56 is released by a handle 59 and the cover is raised about its pivot 57 to allow the housing 45 to be oscillated about the pinion 44 and disengage the gear 50 from the lead screw 21. The latter is then rotated by a handle 97 to move the cutter slide until a pointer 98, Fig. 1, thereon registers on a scale 99 on the guide 121 the length of thread required on the work, whereupon the gear 50 is engaged with the gear 28 appropriate to the pitch of thread required and is locked by closing the cover 56. The cutter is set to the diameter of the work by rotating a dial 87, Figs. 2 and 5, until one of the long radial lines thereon, bearing the number of the pitch of thread required, is adjacent a scale 95 on the cutter head 64 and in line with the horizontal plane MN of the machine. The division on the scale 95 numbered according to the diameter of the work is next brought opposite the short radial line of the dial 87 and locked there by the nuts 65, the distance between the corresponding long and short lines of the dial representing the depth of the thread for that particular pitch. The screw is then cut by rotating the hand wheel 78 and causing the pinion 35 to roll around the gear 10, thereby rotating the casing 12 and cutter head about the work and also traversing the head and slide 13 axially. When the pointer 98 reaches the zero mark of the scale 99 the required length of thread has been cut. For cutting an internal thread the scale 91, Fig. 5, is used in conjunction with the dial 87 to set the cutter to the required diameter and a cutter of smaller diameter is used. In operating on short work pieces the casing 12 may be.secured on a bench by a foot or stirrup piece &c. or in a vice and the chuck and work are then rotated by the pinion 35 whilst the cutter head is traversed axially only. In order to rectify or bore the work prior to screwing, the cutter 73 is replaced by a cylindrical cutter which also receives a planetary motion relatively to the work, but in setting the cutter to the correct diameter the scales 91 or 95 are set to the long lines of the dial 87. Screw threads of pitches other than those provided for by the gears 28 may be cut by changing these gears, together with the cutter, and square, half round, acme and other threads may be cut by appropriate cutters. Chucks.-The chuck jaws 3 are located in radial slots 2 in the body 1 and are pivoted on pairs of links 4 which are pivoted at 5 to the body to give the jaws a parallel motion when moved axially by a flange 7 on a screwed sleeve 8 which is actuated by a rotatable sleeve 8<1> knurled at 8<11> for rotation by hand. Cutter arbors and mountings.-The cutter spindle 71 is secured in the driving shaft 70 by a milled nut 74 and end play of the shaft is taken up by a nut and lock nut 76.