Dec. ‘10,1946. ‘ A, H, oRcuTT 2,412,284 > CONTROLLING MEANS FOR FLUI-D OPERATED MACHINE TOOLS ' Filed Dec. 26 , 2 Shee‘ts-Sheét 1 1945 h/ r311 H J- |__§ - . X n u ‘4/\/ F, o Z‘ 0 OAH SE’ 0 m ‘’ Q m 61/). I, k 112/ z) éizzftiof ' 02015217 Dec. '10, 1946. A‘. H. ORCUTT ' 2,412,284 CONTROLLING MEANS FOR FLUID OPERATED MACHINE TOOLS Filed Dec. 26, 17945 2 Sheets-Sheet 2 v . Patented Dec. 10, 1946 2,412,284 sTATes PATENT _ 2,412,284 CONTROLLING MEANS FOR FLUID OPERATED MACHINE TOOLS 7' _> v‘Arthur Hitchcock Orcutt, Shirley, near Birming ham, England, assignor to The Gear Grinding Company Limited, Shirley, near Birmingham, England Application December 26. 1945, Serial No. 637,25 - _ In Great Britain December 29, 1944 3 Claims. l ' (01. 51—233)' 2 ‘ valves in a control box It situated at the front. of V This invention relates‘ to ?uid operated ma chine toolsof the kind. in which a reciprocatory‘ the machine. This box'contains a pair ‘of‘ro work- or toolé-carrying slide is movable on a hori tary valves whichserve to determine whethergthe zontal bed by pressure of oil 01' other liquid in a cylinder containing a plunger. In such machine tools it is usual to provide on the machine a tap machine shall be operated at‘ a high or a low rate of speed. Levers m on the outer ends of_ the the slide at or near either limit of the movements spindles q of these valves are operable by a hand lever n. The machine is intended for grinding longitudinal splines on the work piece. For aue of the slide, the tappet being adapted to actu tomatically controlling the reciprocation of the pet adapted to be actuated by adjustable dogs on ate a stopping or reversing valve _(herein termed 10 slide (at the rate determined bygthe position of the hand lever 11), a pair of adjustable dogs 0 a controlling valve) in the system associated with the cylinder. Also there is usually arranged with are secured on the front of the slide. These dogs such a machine tool, means for regulating the actuate a tappet associatedv with a controlling valve (in this case a reversing valve) so that at rate of speed of the slide which means may be incorporated ‘with the said. valve, or may con 15 the end of eachtravel ofvthe slide the/direction of action is automatically reversed. ' ' ' " sist of a separate valve or valves: ‘It is well known It will be understood that when the slide travels that when the slide operates at relatively high ' at its high rate of speed it tends to overrun the speed it tends to over-run its normal limits un position at which reversal of motion is required, der momentum. Thus if the dogs are set to stop or reverse the motion of the slide at a given po 20 as already explained. This condition is usually undesirable and in some cases must be prevented, sition when the slide is moved at its slow rate, especially when the splines extend along only a the slide will often over-run that position with part of the length of the work piece, it being the same setting of the dogs when moved at its essential in this case that at either rate of speed higher rate of speed. For some purposes it is important that the slide should be stopped or 25 the motion of the slide should be reversed at exactly the correct position. The purpose of the reversed at a given position independently of present invention is to enable this requirement to its rate of motion, and the object of the present be satis?ed in a convenient manner. invention is to enable this requirement to be met The mode of carrying out the invention on the in a simple and satisfactory manner. machine shown in Figure 1 will now be described The invention comprises the combination of with reference to Figures 2 and 3 which illustrate a tappet, and a connection between the said speed the invention more fully than Figure 1. The valve regulating means and the tappet whereby on levers m are interconnected by a link 10, and on moving the said means to the fast or slow posi one of the levers m is formed or secured a cam tion an appropriate change is made in the posi tion of the tappet. 35 r. The hand lever n is connected to one of the In the accompanying drawings: ‘levers m by a link Z. Also on the front of the valve box It is pivoted a lever s one end of which Figure 1 is a front elevation of a spline shaft grinding machine provided with the invention. rests on the cam, this end being held in contact with the cam by a spring 15. The other end of Figures 2 and 3 are respectively front eleva tion and plan illustrating to a larger scale than the lever s is connected by a link u to a lever 22 pivotally mounted on the top of the box It. To Figure 1 the portion of the machine which em the lever 'v is pivotally attached a tappet lever to bodies my invention. carrying a pin :1: which serves as the tappet, the To elucidate the purpose of the invention I will upper projecting end of the tappet pin being ?rst describe brie?y the main features of the machine shown in Figure 1. On the bed a of the .45 arranged in the path of the dogs 0. The lower end of the tappet pin :0, in this example, engages machine is mounted a horizontal reciprocatory slide b which carries an indexing head 0 and a a connecting piece 1:; which is carried by and is tail stock (1, the work piece 6 being carried by the transversely slidable on a slide bar 2, which is parts 0 and :1. At the left hand end or the slide movable in the direction of its length as indicated is mounter a trimmer f for periodically trimming 50 by the arrow in Figure 3. This bar serves to the grinding wheel .17, the latter being carried actuate the controlling valve in any convenient on a vertically movable slide it which is adjust manner. As the bar 2 and the controlling valve able by a hand wheel 1'. The slide is recipro are already known, it is unnecessary for the cated by a plunger in a hydraulic cylinder (not present purpose to describe or illustrate them, it shown), and ‘the motive ?uid is controlled by 55 being su?icient for the’ present purpose to under 2,412,284 " " " 3 cation of the invention to a spline shaft grinding i stand that longitudinal movement of the bar 2 serves to operate the controlling valve. It will be noticed that each dog 0 is formed with an in machine, it may be applied in essentially the clined striking face, andthe arrangement is such same manner to gear wheel grinding and other forms of ?uid operated machine ‘600,181 . ' that when either dog strikes the upper end of the tappet pin :c' the latter is moved by the dog in the claim as new and desireto secure byLetters Pat direction for moving the bar a in the appropriate direction. During each movement the lever w Having thus described my invention what'I ‘ which carries the pin rocks about its pivotal QQne‘ nection with the lever '11. ‘ In the example illustrated it is required to. de ent is: 7 1. In a variable speed ?uid operated machine 'tool having a reciprocatory slide carrying dogs for. actuating a tappet associated with a con trolling valve, and having also manually operable termine accurately the reversing positionof the speed regulating? means, the combination of a slide when it is moving towards the left. When the machine is at rest the hand lever n occupies the position shown in the drawings, To obtain 1.5 slow speed travel of theslide the lever n, is moved to the left. This causes the tappet pin to be moved to the right, thus bringing it to the ap propriate position relatively to the right hand dog. To, obtain high speed travel the hand lever 20 movable tappet, and a connection between the tappet and the speed regulating means whereby on moving the said meansrto the fastor slow position’ an appropriate change is made in the nvis moved further to, the left. ~ This causes the ing means, a tappet'arranged in operative ‘con, nection with the controllingvalve, a lever carry; tappet pin to be moved further to the right and position of the tappet. 2. In a machine tool having the features specié ?ed in claim 1, the combination of a cam arranged in associationrwith the speed regulat ing the tappet, and means interconnecting the _ so cause it to be struck by the right hand dog at a cam and tappetlever, sufficiently earlier period in the travel of the slide 3.. In amachine tool having the features speci to, ensure that notwithstanding the increased 25 ?ed in claim 1, the combination of a cam arranged momentum of the slide it will not over-run, but in association with a lever‘of the speed regulat come to rest at the same position as when the ing means, a lever operable by the cam, a tappet slide was actuated at the slow rate. arranged in operative connection with the con By this invention the desired result, is obtained in a very simple, convenient and reliable man 30 trolling valve, .a' lever carrying the tappet, a lever carrying, the tappet lever,v and a link intercon ner. The invention is not, however, restricted necting the last named’ lever with the‘ lever which ‘to-the example described. as the mechanical de is operable by the cam. tails may be modi?ed to suit different require ments. Also it will be understood that whereas I have in the foregoing described a specific appli-v ARTHUR HITCHCOCK oacurlr; '