US2069189A - Hydraulic motion-controlling means - Google Patents

Description

Jan. 26, 1937. w. TAYLOR 2,069,189

HYDRAULIC MOTION CONTROLLING MEANS Filed Oct. 25, 1934 4 Sheets-Sheet 1 Li G] Hull lllll Illlllllilfllllll INVENTOR BY h; ATTORNEY Jan. 26, 1937. TAYLOR 2,069,189

HYDRAULIC MOTION CONTROLLING MEANS Filed Oct. 25. 1934 4 Sheets-Sheet 2 l VENTOR M l M ATTORNEY wan 1.14m

Jan. 26, 1937. w. TAYLOR 2,069,189

HYDRAULIC MOTION CONTROLLING MEANS Filed Oct. 25, 1934 4 Sheets-Sheet 5 INVENTOR #4 ATTORNEY Filed 0m. 25, 1934 4 Sheets-Sheet 4 ":VENTOR ATTORNEY Patented Jan. 26, 1937 PATENT OFFICE HYDRAULIC MOTION-CONTROLLIN G MEANS William Taylor, Leicester, England, assignor to Kapella Limited, Leicester, England, a corporation of England Application October 25,1934, Serial No. 749,966 In Great Britain October 26, 1933 This invention relates to and has for its principal object the provision of means for hydraulically actuating and controlling the cutter of a copying machine of the kind in which the cutter 5 is mounted on a frame which swings in an are about an axis. Such machines may be of the lathe type where it is desired to reproduce articles of varying diameter or configuration, such as ornamental columns or the like. Another type of machine to which the invention is applicable is an engraving machine of the pantograph type.

Heretofore, in machines of that kind the pressure required to force the cutter against the work has been supplied manually through the stylus. According tothe present invention such pressure is supplied hydraulically, and all. the work the operator has to do is move a suitable control valve or valves by operating the stylus.

Three suitable-forms of construction embodying my invention are shown, by way of example, in the accompanying drawings, in which:

Fig. 1 is a plan view of a machine of the lathe type designed to reproduce articles of varying diameter;

Fig. 2 is a front elevation of the machine shown in Fig. 1;

, Fig. 3 is an end elevation of the same machine; Fig. 4 is a plan view of a copying machine of the pantograph type adapted for engraving objects in two dimensions.

Fig. 5 is a front elevation of the machine shown Jm 6 is a" plan view of a similar machine adapted for engraving objects in three dimensions; and Fig. 7 is a front elevation of the machine shown in Fig. 6.

In every application of this invention, there are certain essential features which I will first describe.

A hydraulic cylinder adapted to move the machine member may have any convenient form. It may be an ordinary cylinder fitted with a piston, and either the cylinder or the piston may be connected to the machine member while the other is connected to the machine base or other part with respect to which the member is to be moved.

A single-actuating cylinder of this kind is shown in Fig. 3 at N, in which case its piston O is lifted by the hydraulic fluid and depressed by gravity when the fluid is allowed to escape from the cylinder. Another form of hydraulic cylinder is the wing pump, such as is shown, in section,

at K1 in Fig. 7, also in cross-section at B in Fig.

6. This comprises a cylindrical casing K1 provided with a cover 173 and a shaft b4 concentric with it, and provided with adjustable stufiing boxes b5, be. The casing or the shaft may be 5 attached to the machine member to be moved, and the other of them to the part with respect to which it is to be moved.

Attached to the shaft, and filling the casing freely without shake, is a pair of opposed radial 10 blades b7 ba, carried by their hub b9 and attached to the casing; and fitting closely against the hub b9 are a pair of inwardly projecting radial diaphragms 102 Its.

The arrangement is such that the casing is 15 divided into four compartments such that, by admitting fluid under pressure to any opposite pair, the shaft will be turned in one direction or the other.

In order to connect opposite pairs of these 20 compartments two holes bm bu on different levels are drilled radially through the shaft and the hub In so as to connect such opposite pairs independently of one another.

Pipes 1': 18, connected through the casing to the 25 two pairs of compartments respectively, convey fluid from the control valve to the compartments. or serve as drainpipes therefrom.

The fluid, to actuate the hydraulic cylinder, must be under pressure, and is generally supplied 30 in well-known manner by means of a pressure pump adapted to draw fluid from a reservoir at atmospheric pressure, and supplied through a pipe or pipes, which maybe flexible, to a control valve and therefrom to the hydraulic cylinder. 35 Such pumps are well known, and it is unnecessary to describe them in detail.

The control valve, which is actuated by motion of a directing member to control the supply of fluid to the hydraulic cylinder, is a novel and 40 essential part of this invention; and such a valve is shown in section at L in Fig. 4, as well as in other figures, as hereafter described. It comprises a casing L which, most conveniently, is a cylinder, in the bore of which a piston l is fltted so as to slide freely but without substantial shake. The piston is formed near the middle of its length with a groove or neck Z1 into which fluid under pressure from the source is supplied through a pipe M and through. the-cylinder wall. 50

The cylinder has two internal grooves la la formed in it, with a space between substantially equal to the width of the neck 1-: 1n the piston. The piston is also necked at and In so as to leave on it lands of length corresponding sub- 55 the cylinder. The ends of the pistons outside the necks I10 111 are formed to act as guides to centre the piston in the cylinder, but they are grooved or drilled longitudinally to permit fluid to escape from said necks Z10 In to the ends of the cylinder from which the fluid may be drained away by the drainpipes n1 m to the pump reservoir. The grooves Z8 Z9 in the cylinder are connected by a pair of pipes Z3 14 to the two sides of the machine actuating hydraulic cylinder K2.

The arrangement is such that, when the lands 212 ha of the control piston are centred in the grooves la 19 in the cylinder, the fluid in the neck 11 is imprisoned therein and unable to pass freely into the wing pump, while at the same time, the fluid in the wing pump is unable to escape from either of the grooves la la in the cylinder; but when the piston is moved either way in, or relative to, its cylinder, for example in the direction of the arrow in Fig. 4, then the fluid under pressure passes from the piston neck 1 into the groove 15 in the cylinder and thence by the pipe 14 to the chambers k3 k4 of the wing pump, thereby turning the vanes and the shaft of the wing pump in the clockwise direction as seen in Fig. 4. At the same time, the chambers k5 ks in the wing pump are connected via the pipe I: and the groove la in the control cylinder so that fluid escapes therefrom and returns by the drainpipe m to the reservoir.

It will be seen that such a. control valve acts differentially on the two ends of a double-acting hydraulic cylinder, reducing the pressure in one end while it builds up pressure in the other end.

The control valve shown in Fig. 4 is a doubleacting valve adapted to actuate a double-acting hydraulic cylinder, but a control valve may be single-acting and one such is shown in Fig. 5, which is adapted to control the supply of fluid to the single-acting cylinder N which gives motion in one direction against the action of gravity.

While I generally prefer to construct my control valve as above described, I may, instead of using the pipes Z3 Z4, both to supply fluid to the hydraulic cylinder and to withdraw it therefrom and return it to the reservoir via the drainpipes n1 n2, connect the drainpipes m 112 directly to the hydraulic cylinder, one to each end thereof, and so throttle these exits from the cylinder that a sufficient working pressure may be maintained therein whenever the piston of the control valve is displaced from its central position; and for this purpose I may make the central groove 1-: in the control piston of a widthsomewhat greater than that of the corresponding land in the control cylinder so that, these being centred, fluid may pass thereby at a suflicient rate to maintain pressure in the two ends of the hydraulic cylinder, but at these pressures will vary difierentially as the control piston is moved more or less to one side or the other of its central position.

In order that such a control valve shall, with but slight endwise movement of its piston, operate in the cylinder, the diameter of the cylinder should be relatively large.

In the roller-engraving machine shown in Fig. 1, A is a. shaft housed in bearings on a base, and having mounted concentrically thereon an object roller B to be engraved, and a model roller C whereen is already engraved an original of the pattern which it is desired to cut on the object roller B. D is a shaft adapted to slide and to rock in bearings E, E1 on the frame, and the *stantially with the widths of the grooves la 19 in shaft is screwed at F and engaged by a nut G rotated mechanically at a slow rate by any convenient means, for example the pulley H and a belt. The nut G is provided with teeth on its periphery, and engages a wheel I keyed to the shaft A so that the shaft D is caused to move slowly endwise while the rollers B and C rotateslowly.

Fixed to the shaft D is an arm J adapted to carry a spindle mounted in a quill K and driven by a pulley L, and carrying at its lower end a rotary cutting tool M. The axis of the spindle and of the cutting tool approximately intersects the axis of the shaft A. The arm J has a forward extension J; beneath which, and fixed to the base, is a hydraulic cylinder N and a piston 0 whose rod 01 is connected to the arm J1 by the pin and slot J2 so that, as the piston 0 moves in the cylinder N, the tool carriage J rocks around the axis of the shaft D, and the tool M moves correspondingly toward or from the axis A.

Fixed on the shaft D is a collar P and a bracket P1, to which is attached the cylinder of a singleacting control valve P2, and between the collar P and the bracket P1 is mounted, for slight r0- tation on the shaft D, a tracer carriage P3 carrying a tracer P4 adapted to bear on the surface of the model roller C, the operative point of the tracer corresponding substantially in form to that of the cutter M. The tracer carriage P3 has an arm P5 linked to the outer end of the rod of the control valve.

A pipe Q supplies liquid under pressure to the control valve P2, a pipe N1 conveys the fluid to the hydraulic cylinder N, and a. drainpipe R returns fluid to the reservoir. The whole arrangement is such that, as the shaft A and the nut G are slowly rotated, the tracer P4 and the cutting tool M are slowly traversed so that they trace helical paths on the model roller C and the object roller B respectively; and as the tracer P4 which, in the arrangement shown, is urged downwards by gravity, moves up and down according to the varying contours of the model C on which it rests, it actuates the control valve alternately to supply liquid to and withdraw it from the hydraulic cylinder N, and thereby causes the cutter to rise and fall in harmony'with the motion of the tracer.

The engraving machine shown in Figs. 4 and ,5 may have a base of any convenient form adapted to hold the object to be engraved and a model thereof, and to such base is fixed an arm A having lugs A1, A2, wherein is housed a shaft B on an axis which I will term the principal axis of the pantograph system to be described.

The pantograph comprises five members C, D, E, F, G, pivotally connected together at the points (1, e, f, g, h, so that they form, as seen in Fig. 4 in plan, a. species of pantograph, such that any motion of the point I gives to the point I, which is intermediate and in a straight line between e and g, a corresponding motion but on a reduced scale.

In the axis I, in a quill J, is mounted a rotary cutter J1 which may be driven by the pulley J2, and is adapted to operate on any object fixed beneath it. In the axis j is flxeda tracer 11 which may be moved manually about the outlines of a model also fixed to the base. The shaft B, which is fixed in the member C of the pantograph, forms also the shaft of the hydraulic cylindexin the form of a wing pump K, the casing of which is fixed to the lug A2. At the upper end, 75

- and surrounding the upper end, of the shaft which to the piston rod ls of a double-acting control forms the combination pivot g of the members 0 and G is a second hydraulic cylinder in the form of a wing pump K2, the casing of which is fixed to the member C and the movable wings to the shaft 9. The member E, at the part between the junction pivot e and the tracer at f, is constituted by a double-acting control valve L, whose casing forms one of the members pivoted at f and whose piston l is pivoted at 11 in the plane of the axes f, e, d. Similarly, the member F is constituted by a control valve L1 whose cylinder forms. one member pivoted at f and whose piston l2 forms one of the members pivoted at h. Fluid under pressure is supplied to the control valves L and L1 through the branched pipe M. From the control valve L, fluid is supplied by-the pipes l3 14 to the two pairs of chambers in the wing pump K2; or, alternatively, is drained therefrom by the branched pipe N. Similarly, pipes 15 1c convey fluid from the control valve L1 to the two opposed chambers in the wing pump K, or, alternatively,

drain fluid therefrom, and the branched pipe N:

drains such fluid to the reservoir.

The arrangement'is such that, on any movement being given to the tracer f1, for example in the direction I, d, the control valve L is actuated to supply fluid to that pair of chambers in the wing pump K2 whereby the member G is caused to turn on the member C round the axis 9, and thereby move the cutter I in the direction 1, (1. Similarly, if the tracer f1 be moved in the direction f, h, the control valve L1 is caused tosupply fluidto the wing pump K, so as to move the cutter I in the direction f, h, and thus movement in any direction of the tracer 1! causes the control valves L, L1, or one or them, to actuate the hydraulic cylinders or wing pumps K, K2, to give corresponding motion to the cutter J1. Figs. 6 and '7 show how the panto'graph engraving machine, illustrated in Figs. 4 and 5 and just described, may be adapted for engraving in a third dimension. In this, the outlines of the pantograph defined by the points d,.e, f, g, B, correspond with those similarly'lettered in Fig. 9, as also do the wing pumps K, K2, and the tracer f1.

For clarity, I have abstained from repeating, in'

' tracer 1'1 is adapted to slide endwise in the members F and E at their junction f, and the quill J is adapted to slide up and down in its housing in the member G. Pivoted about a secondary axis b, In, intersecting at right angles the primary axis B, is mounted, on a bracket be attached to the shaft B, a third hydraulic cylinder in the form of the wing pump K1 of the kind already described, the shaft of this being fixed to the bracket b: and

' the casing to an arm 0 capable of up and down movement round the axis b, In, and this may be counter-weighted by the weight P. Mounted on the arm 0, and capable of sliding along it in a straight line to and from the primary axis B, is a pair of sliders 0, 01. the former of which is adapted to engage the upper end of the quill J so as to depress it when thearm 0 moves downwards; When the arm O'moves upwards, the quill J may be lifted by means of a spring, or may be pivotally connected to the slider o, and thereby to the arm 0. The slider 01 embraces all sides of the bar 0, and is pivotally connected at the point valve Le of the kind already described, and whose cylinder is fixed to the upper end of the tracer f1. Fluid under pressure is supplied to the control valve by the pipe me and thence to the hydraulic cylinder K1 by pipes 11 la for the purposes already described. 1

Fluid is drained from the control valve by the branched pipe Ne.

As the tracer fl is moved in any direction, so as to move its axis nearer to or further from the principal axis B, the sliders o, 01 move correspondingly along the bar 0, and as the tracer h is moved in any direction tangential to the line B, i, the bar 0 swings correspondingly round the primary axis B.

The whole arrangement is such that, as the tracer I1 is moved up or down upon the surface of any model, for example Q, the control valve L2 is actuated to supply fluid through the pipe la to the wing pump K1, whereby the arm 0 is lifted and therewith the cutter J1 and the piston It in the control valve.

This action continues so long as the tracer f1 continues to rise, but, on its returning, the action is reversed, fluid is drained to the reservoir from the wing pump K1 by the pipes la, No, while fluid under pressure is supplied to the other pair of chambers in the wing pump, whereby the arm 0 and the cutter J1 are lowered in unison with the motion of the tracer f1.

It will be seen that, in all these applications of my invention, the' motion of the piston in the control valve is limited; in other words, its stroke is small; and this may be limited and varied by any convenient means such as screw stops in the ends of the control cylinder; but where, as in accurate engraving of metal surfaces, the cutter must follow all movements of the tracer or directing member with but trifling lag, the back lash in the control valve must be very small. In such cases it may be convenient to actuate the control valve not directly, by motion of the directing member or tracer, but indirectly, by fitting to the directing member one or more electrical contacts adapted to be made or broken by its motion, and by actuating the control valve by means of one or more electro-magnets energized by a current, or currents, established by said contact, or contacts, in a manner which will be rmderstood without detailed description. In such case the control valve may be fixed wherever it is convenient to place it, for example on the frame of a machine or on any moving member, or adjacent to the hydraulic cylinder which it is to actuate.

In this specification, when I speak of the directing member and the hydraulically moved machine member being linked together so that they move in unison, I mean that they move simultaneously subject only to the small lag between them resulting from that freedom of the direct-,

' able, among other reasons, on account of economy in manufacture, and because the piston tends to float centrally in the cylinder with a fluid fllm between them.

-By a hydraulic cylinder I mean any suitable kind of chamber expansible by the fluid under pressure therein and adapted, in expanding, to move the movable machine member.

What is claimed is:

1. A forming machine, comprising a shaft adapted to carry an object roller to be formed and a model roller, means for rotating said shaft and rollers, a frame adapted to swing about an axis parallel to said shaft, means for moving said frame in the direction of its axis, a former and a follower mounted on said frame, the portion of the frame carrying the follower being movable angularly with respect to that portion of the frame which carries the former, a hydraulic motor for moving the second portion of the frame aboutsaid axis, and a valve, one part of which is connected to one of said portions of the frame while the other part is connected to the other of said portions, whereby relative angular move ment of said portions permits fluid to pass through said valve to or from said motor until the initial relative angular position of the two portions is restored. a

2. A forming machine, comprising a pantograph, a follower and a former mounted thereon, two hydraulic motors for moving the pantograph with respect to its pivot of support, one of said motors being arranged to move the former circularly around said pivot while the other motor is arranged to move theformer toward or from said pivot, and two valves connected to the follower, one valve being arranged so that when the follower is moved circularly around said pivot fluid is supplied to the first motor to produce a corresponding movement of the former, and the other valve being arranged so that when the follower is moved toward or from said pivot fluid is supplied to the second motor to produce a corresponding movement of the former.

motor comprising a segmental cylinder having one radial wall fixed and the other radial wall movable with respect to the cylinder, one of said walls being connected to said pivot and the other connected to said support, and means for admitting or discharging fluid to or from the space between said walls to move said support relatively to said pivot.

4. A forming machine comprising a pantograph including a link mounted at one end to swing about a fixed axis, a second link parallel thereto, two supplemental links connecting the two links, a former mounted on the supplemental link furthest from said axis, two telescopic links pivotally connected together at one end and pivotally connected at their other ends to the ends of the first and second links furthest from said axis, a follower carried thereby, a hydraulic motor for moving the first link about said axis, a second hydraulic motor for moving one of the supplemental links relatively to the first link, and

valves forming a part of said telescopic links and operated by telescopic movement of the parts of such links for controlling the supply of operating fluid to said motors.

5. A forming machine comprising a pantograph, a follower and a former mounted thereon,

a hydraulic motor for moving the pantograph with respect to its pivot of support, said motor comprising a segmental cylinder having one radial wall fixed and the other radial wall movable with respect to the cylinder, one of said walls being connected to said pivot and the other com nected to the pantograph, and means controlled by movement of the follower for admitting or discharging fluid to or from the space between said walls to move the pantograph relatively to said pivot.

WILLIAM TAYLOR.

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