US1945034A - Cam controlled hydraulic feed mechanism - Google Patents

Description

Jan. 30, 1934. R. M. GALLOWAY CAM CONTROLLED HYDRAULIC FEED MECHANISM Filed Sept. 26, 1951, 4'Sheets-Sheet 2 IIIIIIIIII Jan. 30, 1934. GALLOWAY 1,945,034-

CAM CONTROLLED HYDRAULIC FEED'MECHANISM Filed Sept. 26, 1931 4 Sheets-Sheet 3 J4 ventoz 4 Sheets-Sheet 4 gwuentoz TILI' I'll-Ill], IIIIIIIIIIIIIIFII-IIII R. M. GALLOWAY CAM CONTROLLED HYDRAULIC FEED MECHANISM Filed Sept. 26, 1931 Jan. 30, 1934.

Patented Jan. 30, 1934 PATENT OFFICE CAM CONTROLLED HYDRAULIC FEED MECHANISM Robert M. Galloway, Richmond, Ind., assignor to The National Automatic Tool Company,

Richmond, Ind., a corporation of Indiana Application September 26, 1931 Serial No. 565,352

11 Claims.

This invention is concerned with power transmission means and more specifically relates to a combination of hydraulic and mechanical feeding means whereby certain attributes of each are.

coordinated in a novel and exceptionally advantageous manner. I

Hydraulic power means have been extensively employed in propulsion systems. Such characteristics of hydraulic power means as exceptional flexibility, including great selectivity as to range and speed of operation in either direction, and ease of automatic or manual control have rendered them of great advantage in the operation of such, mechanisms as machine tools.

Despite the advantages possessed by hydraulic transmissions the more positively regulated types of feed have been required under the circumstances of many cases where a very accurate, regular and positively determined feed is necessary.

The invention, as disclosed herein, proposes a coordination of these types of transmissions whereby the desired attributes of each are rendered available in a single organization. Primary features of the arrangement illustrating the invention include the propulsion of the shiftable member through its major movement in either direction by the medium of hydraulic means; and a mechanically controlled movement through the normally shorter feed range when extreme accuracy and regularity of movement is desired. The mechanical means further serves to definitely limit the final point of advance under the feeding movement whereby the elements of inaccuracy resulting e. g. from overrunning, due to'r'nomentum and other indeterminate variations characteristic of hydraulic transmissions, are avoided. The mechanical control means, as devised, further eliminates the abrupt termination of the forward feed and backing 01f of the head, typical of purely mechanical or hydraulic systems, resulting in a surface not smoothly finished.

These combined characteristics of operation are produced through means of a system in which the machine head, if such be the element to be propelled, is advanced, at any rate or combination of rates, through the larger portion of a stroke until the tool engages, or is about to engage, the work for the machining operation. At this point in the travel of the head it meets with an abutment interposed in its path of movement. The hydraulic pressure remains on but is ineffective to further advance the head, except insofar as permitted by the abutment means. The

feed is then eifected through the operation of mechanical means automatically introduced at this point which serves to produce a progressive adjustment of the abutment means in a direction to permit a correspondingly regulated slow advance of the head under the influence of the hydraulic propelling motor.

A unique organization for producing the adjustment of the abutment means is provided which operates in a very smooth and regular manner. As a primary feature of this mechanism, as specifically devised and disclosed herein, a tapered cam is provided interposed between the head and a fixed abutment, means being provided for sliding the cam transversely of the head whereby the effective portion restraining the advance of the head becomes gradually narrower and the advance of the head becomes a function of. the inclination of the cam and its speed of withdrawal which factors, it will be understood, may be readily altered or varied to suit the circumstances of the particular case.

The functioning then of this general combination, has as itsprimary characteristics, a hydraulic means for advancing the movable head through a long range, if circumstances require, and at any rate desired, in accordance with the ready control of hydraulic transmissions; a mechanically controlled feed automatically thrown into operation at the termination of the rapid advance; and upon the completion of the machining operation a rapid return of the head to its initial position through the medium of the hydraulic' propelling means. The system, therefore, possesses all the advantages of hydraulic propulsion, the hydraulic features being effective for producing long range movements and being capable of ready control thereof; and further, possesses all the advantages of a mechanical feed during the actual machining operation. This latter property of the system is achieved, it will be noted, without resort to cumbersome and impractical cam constructions e. g. for producing long rapid traverses of the translatable head.

An important feature of the arrangement described so far in general, is the availability 01' means for providing a dwell at the termination of the normal feeding advance, such dwell resulting in an accurately and smoothly machined surface difficult of accomplishment in systems where, upon completion of the forward movement, the translatable head is immediately released from the force urging it forward. All that is necessary in the present organization to accomplish this property is to maintain the abutment means stationary in its effect upon the translatable head while the hydraulic motor continues to urge the head forward. As specifically disclosed herein this is accomplished through the provision of a section on the slidable cam of straight contour whereby continued withdrawal thereof produces no variation in the effective position of the abutment means.

A particularly important feature of the present invention, is the ability to maintain an exact time relation between the advance of the head, and some other primary movement of the machine such as the rotation of a tool. This is accomplished through derivation of the drive for the cam from some mechanically operated element in the general mechanical drive of the machine. For example, as shown in the construction herein, the adjustment of the cam is produced through a mechanical drive having its source in a gear train primarily designed for rotating one of the spindles of the machine. The result is that the feeding movement of the head bears an exact relation to the rotation of the spindle. This relation, therefore, it will be seen, may be of suflicient accuracy even as to produce a positive threading operation.

The organization presents further novel features, which will be apparent from a detailed study thereof, chief among which is an 'excep tionally simple, reliable and flexible control means, including unique devices and mechanisms for operating the cam control.

To enable others skilled in the art so fully to apprehendthe underlying features hereof that they may embody the same in the various'ways contemplated by this invention, drawings depicting a preferred typical construction have been annexed as a part of this disclosure and, in such drawings, like characters of reference denote corresponding parts throughout all the views, of whic Figure 1 is a general organizational view depicting a typical machine tool in which the present invention may be employed to advantage. Fig. 2 is a top plan view showing a portion of one of the tool heads. Fig. 3 is a fragmentary .cross sectional view through the tool head of Fig.2. Fig. 4 is a transverse sectional view taken on the line 4-4 of Fig. 3. Fig. 5 is a Partial vertical end view of the inner end of a tool head designed to show the gearing for rotating the spindles. Fig. 6 is a detail view of a. trip dog employed in the automatic operation of the drive means. Fig. 7-is a diagrammatic view designed to show, in a clearer manner, the

general features and organization. I

As shown in Figure 1 the general characteristics ofthe specific machine tool, in which the present invention is incorporated, consists of a long supporting base 10 upon which the translatable heads 11 and 12 are capable of having a relatively long range of movement. Each of the heads carry a plurality of tool spindles, three in number in the present construction, those on head 11 being indicated at 13, 13 and 13. The spindles are designed to carry tools operating on work-pieces supported on the central portion 14 of the base. Details of the work-carrying mechanism are not disclosed but are indicated in general by the dotted outlines 15, it being understood that such outline diagrammatically illustrates a typical work-supporting means which may be fixed or indexible in accordance with the particular charoperation of the complete scribed, is normally at a rapid rate.

vance of the tool heads.

The general construction of the two tool heads 11 and, 12 are similar and the description will, therefore, be limited to only one of these heads, the head 11, being illustrated in Figs. 2, 3, 4 and 5 and shown at the left in the diagrammatic Figure 7. The tool head 11 is translatable on the ways 17,, the translation in general being produc'ed through the medium of the piston 18 operative in the cylinder 19 and connected through the piston rod 20 and bracket 21 to the translatable head 11.

The general features of the tool head include a driving motor 22 mounted thereon having a rotarypower' shaft 23 carrying external gear 24 meshing with and driving the internal gear 25 which latter gear is mounted on the shaft 33 carried by the spindle 13. Similar gear trains lead to the spindles 13 and 13 located at the back side of the head. These latter two spindles being in the same vertical plane coincide in the plan view of Fig. 2. In Fig. 2 only the drive to the lower spindle 13 is shown, the drive to the upper spindle 13 being'omitted in order that the auxiliary drive to the cam control mechanism, to be subsequently described, may be more clearly illustrated. This drive to the lower rear spindle 13 includes the gear 29 which drives the gears 34, and 35 mounted on the same shaft with 34,

which gear 35 meshes with the gear 36, which in turn drives the gear 37 mounted on the spindle 13. A similar drive to the upper rear spindle 13 is provided which includes the gears 29, 34, 35 and 35 (Fig. 5) and additional gears not shown. An auxiliary drive to the cam control mechanism may be taken from one of'these gears in the various trains and, as shown, gear 36 also drives a. gear 38 fixedon the shaft 38, which shaft also carries the gear 39 keyed thereon. The supports for the shaft 38 include suitable bearings in the upright standards 2'7 and 28.

As has been described the head is translated in forward and reverse directions by means of the hydraulic motor with suitable control means.

This travel, except when under the control of the adjustable abutment means, now to be de- The ad- .iustable abutment means limits the forward advance of the tool and prescribes a progressive advance thereof during a relatively short range of movement which, in a machine of this type,

would normally comprise the tool head travelduring which the machiningof the work-piece occurred. The adjustable abutment means consist primarily of an elongated'cam 40'movable transversely of the machine in suitable guides 41 and 42 shown particularly in'Fig. 3. Suitable bearing rollers 43 engage the rear ofthe ad- ,justable cam 40 to form a supporting means therefor but one relatively free of friction as the spur gear 55 cam 40 is transversely adjusted while being sub rack plunger 61, is determined'by its engagejected to the force of the hydraulic motor effective during such period.

The slidable cam 40 and its associated mechanism. for operation thereof, are mounted for the most part in a supporting bracket 44 secured to the main base 45 of the translatable head 11. The forward part of the bracket 44 carries, in a horizontal opening thereof, a stop plunger 46 etxending in the direction of. themovement of the tool head. The plunger is provided with longitudinal teat keys 46 to allow endwise movement but prevent any turning thereof. The inner end of the plunger carries a forked portion 47 having therein a roller 48 adapted to engage with the forward face of the cam 40. The forward end of-the plunger 46, at a particular point in the advance of the tool head, will engage the abutment 16,. subsequent advance of the tool head being dependent uponthe transverse withdrawal of the cam 40. As the cam 40 moves to the right in Fig. 2 the roller 48 of the plunger 46 will ride down the inclined portion 49 of the cam 40 and permit the gradual advance ofthe tool head under the force of the hydraulic propelling means.

The means for translating the cam will. now be described. As shown in Figs. 3 and 4 a bracket 51 is mounted on, and adapted to swing about the shaft 38 as a center which shaft is supported at its outer end by the fixed arm 52 projecting from the vertical wall 2'7. Bushings 53 provide a bearing for the swivelable frame 51 on the shaft 38 The frame 51 carries in suitable bearing bushings the shaft 54 upon which is keyed the and the worm gear 56. The spur gear 55 meshes with the gear 39 heretofore described carried by the shaft 38*.

Reverting to the cam 40, it will be noted that the flange 5'7 thereof is provided with rack teeth 58 which meshes with gear 59 fixed on the stud 60 vertically mounted in the bracket 44 of the tool head. The tool head 11 carries also a plunger 61 operative in fluid pressure cylinder 62, which plunger is provided with rack teeth 63 also meshing with the spur gear 59. Fluid pressure is continuously effective within the cylinder 62 and normally tends to maintain-the cam 40 in the position shown in diagrammatic Figure '7.

The upper end of the stud 60 carries thereon the worm gear 64 with which the worm 56 is adapted to be selectively engaged or disengaged. Engagement is e'fiected through a mechanism consisting of a fluid operative piston 65 working in the cylinder 66, the piston 65 being provided with rack teeth 6'7 meshing with the gear 68 mounted on the vertical stud 69 supported in the bracket 44. Integral with the gear 68, or fixed thereto, is a rotary cam member '70 bearing against the cam plate '71 of the swivelable bracket 51. Admission of fluid to the cylinder 66 in a manner to be described hereinafter serves to rotatethe gear 68 and the cam-70, forcing the worm 56 into engagement with the worm gear 64, thereby effecting a drive of the gear 59 and withdrawal of the cam 40. A spring '73 normally presses against the flange '74 of the swivelable bracket 51 and upon release of the cam '70, frees the worm 56 from engagement with the worm gear 64 and interrupts the'withdrawal of the cam 40. The extent of withdrawal of the cam 40 is determined by-engagement with the operative stem of the fluid pressure valve '75, and.

ment with adjustable stud '76. A double stepped elongated washer '77 having aslot '7'7 therein is provided for the stud '76. By loosening the stud from the position shown in Fig.2 the washer may be slid over and the stud run down to the lower step of the washer, in which case the stud will occupy the position shown in dotted lines in Fig. 2.

Details of the automatic control means for the machine will now be described. These include a main distributing valve '78 having therein a valve plunger '79 adapted to direct the flow of fluid from a suitable source, such as a hydraulic pump delivering liquid through the pipe and alternatively through the pipes 81 or 82 to the forward or reverse ends of the cylinder 19. Exhaust from the valve '18 is through the pipe 83. The control means includes an air pressure system, air pressure being admitted from a suitable source through the pipe 84 to the air valve 85, the pipe 84 having branches 86 leading to the cylinder 62 to maintain a continuous pressure therein'and a branch 8'7 leading to the valve '75. Opening of the valve '75 serves to admit fluid pressure through pipe 88 to one end of the cylinder 66', a connecting branch 89, also leading to one end of the air cylinder 90, having a piston 91 operative therein. An adjustable dog 92, mounted on and movable with the tool carriage, is adapted to engage the plunger 93 of the valve 85 to admit air pressure to the pipe line 94 leading to the end of cylinder 66 opposite to the pipe 88.

The dog 92 is of the one-way operating type, as shown in Fig. 6. The latch 96 of this dog is hung on a pivot at 9'7 and is spring pressed to the .position shown, by the coil spring 98. During movement of the dog 92 to the right inFig. 1, the latch '96 positively depresses plunger 93 of the valve 85; but upon reverse movement of the dog to the left, the dog is permitted to turn on its pivot and ride over the plunger 93. Manual control means of any desired type may be provided, one such arrangement being shown in Figure 1 consisting of a rotatably mounted manual lever 99 having rigidly secured thereto the crank arms 100 connected through links 101 to the valve rods 102. The opposed ends of the valve rods are provided with slots 103 in which a stud on the outer end of the respective links 101 engages. Each v a Figure '7. Subsequent independent movement inwardly of either valve 79 is permitted by slots 103.

Having described the details of construction a typical cycle will now be described. The manual control level is operated to shift the valve '79 to the position shown in Fig. '7 at which time hydraulic fluid is admitted to the left end of the cylinder 19 and the piston 18 moves to the right carrying the head 11 therewith at a rapid rate. Simultaneously with the engagement of the plunger 46 with the fixed abutment surface 16, or immediately previous thereto, the latch memzer 96 of the dog 92 engages the plunger 93 to open the valve 85 admitting air to the right end of cylinder 66 and the piston 65 proceeds to move to the left in Fig. 5 rotating cam '70 and engaging the worm 56 with the worm gear 64. Thereupon the I gear 64 is rotated and likewise the gear 59 which serves to withdraw the cam 40 moving it upward in Fig. '7. Hydraulic pressure through the pipe 81 continues to act on the main piston 18 holding the head in firm engagement with the abutment means. As the cam 40 is progressively withdrawn the inclined surface 49 passes along the roller 48 of the plunger 46 and a slow advance of the head is permitted effecting a feed during which time, in a machine of this type, the actual cutting of the work-piece occurs. The cam 40 continues to be withdrawn and the roller 48 ultimately comes in contact with the straight portion 50 of the cam 40 producing a dwell of the tool head, enabling the production of an accurately finished surface of the work-piece. This proceeds until the cam 40 engages the plunger of the air valve which admits air to the left end of cylinder 66 to cause the piston 65 to move to the right in Fig. 7 and release the worm 56 from the worm gear 64 and interrupts the movement of the cam 40. Simultaneously with the admission of air to the left end of cylinder 66, air is also admitted through the pipe 89 to act on the piston 91 connected to the valve member 79 moving the valve to its extreme right hand position, at which time hydraulic fluid is admitted through the pipe 82 to the reverse end of cylinder 19 causing the rapid traverse reverse of the tool head 11, As soon as the mechanical drive through the gear 59, to the cam 46, is interrupted, the fluid pres sure in the cylinder 62 serves to return the cam 40 to its original position as rapidly as permitted by the withdrawal of the 'head 11. After the complete rapid traverse in the reverse direction of the tool head has been effected hydraulic pres sure continues to act in the same direction on the piston 18 to maintain the tool head 11 in its retracted position until the next cycle is initiated through manual operation of the lever 99 to again move the valve member 79 to the position shown.

The primary features of the arrangement, it will be noted, include a hydraulic motor 19 for producing long range movements of the tool head in forward and reverse directions and a positive mechanically controlled feed. The cam 40, it will be noted, is withdrawn through mechanical means which derives its driving power from a rotary element in a gear train leading to one of the rotary spindles. A feed exactly timed with the rotation of a spindle is thereby produced and is, in fact, of such accuracy as to provide a positive feed for such operations as that of screw threading. I

The rate of mechanically controlled feed may be readily altered to suit the requirements of any particular class of work through selection of different gear ratios in the drive to the cam and/ or variations in the cam contour.

Without further analysis, the foregoing will so fully reveal the gist of this invention that others can, by applying current knowledge, readily adapt it for various utilizations by retaining one or more of the features that, from the standpoint of the prior art, fairly constitute essential characteristics of either the generic or specific aspects of this invention and, therefore, such adaptations should be, and are intended to be, comprehended within the meaning and range of equivalency of the following claims.

Having thus revealed this invention, I claim as new and desire to secure the following combinations and elements, or equivalents thereof, by Letters Patent of United States:

1. A machine tool combining a movable member; a hydraulic motor for propelling said member; adjustable abutment means for limiting the movement of said member: mechanism for adjusting said abutment means; clutch means for controlling said mechanism; and means for operating said clutch means in timed relation with the movement of said member whereby upon engagement of said abutment means the latter is progressively adjusted to effect afeed of said member.

.2. A machine tool combining a movable member; a hydraulic motor for propelling said member; abutment means including an adjustable .cam engageable by said member for positively ing mounted for translatory movement transverse to the direction of movement of said head; a fixed abutment; a stop member carried by said head engaging said cam and also adapted to engage said fixed abutment, said abutment cam and stop member serving to positively limit the movement of said head in one direction under the force of said hydraulic motor; a rotary spindle carried by said head; means for rotating said spindle; and mechanism connected to be operated in timed relation with the rotation of said spindle for transversely translating said cam, the latter being contoured to permit progressive advanca of said head underthe urge of said hydraulic motor whereby a feed is efiected.

4. A machine tool combining a movable member; abutment means in the path of movement of said member; an adjustable cam interposed between said abutment means and said member; a rotary member on said machine tool; mechanism for adjusting said cam in one direction operated in timed relation with said rotary member; clutch means for rendering said mechanism effective or ineffective; said cam being contoured to permit a progressive advancement of said member upon adjustment of said cam; and impositive means acting on said cam and effective to return it to its initial position upon release of said clutch means.

5. A machine tool combining a movable member; a hydraulic motor for propelling said member; abutments means including an adjustable cam therein for positively limiting the movement of said member; mechanism initially operative when said member is advanced into engagement with said abutment means to render operative thereupon said cam adjusting mechanism, said cam being contoured to thereafter permit a progressive advancement of said member in accordance with the rate of operation of said mechanism.

6. A machine tool combining a movable member; a hydraulic motor for propelling said member; abutment means including an adjustable cam therein for positively limiting the movement of said member; mechanism for adjusting said cam; and means for rendering said mechanism operative when said member is advanced into engagement with said abutment means, said cam her; a hydraulic motor for propelling said membeing contoured to thereafter permit a progressive advancement of said member in accordance with the rate of operation of said mechanism; means for rendering sad mechanism inefiective at a predetermined point in the advancement of said member and for reversing said hydraulic motor and thereby the direction of movement of said member; and means for thereupon returning said cam means to its initial position.

7'. A machine tool combining a movable member; a hydraulic motor for propelling said member; abutment means including an adjustable I head;

cam engageable by said member for positively limiting the movement of said member; selectively operative mechanical means for adjusting said cam in one direction at a predetermined fixed rate, said cam being contoured to permit a progressive advance of said member under the force of said motor; and impositive-means acting upon said cam to return it to'its initial position when said mechanical means is inoperative. I

8. A machine tool combining a translatable a fluid pressure motor for moving said head in forward and reverse directions; control means therefor; abutment means including an adjustable cam for limiting the forward movement of said head; power driven means for adjusting said cam; means for rendering said power means effective or ineffective at predetermined points in the movement of said head, said cam being contoured to permit a feed of said head under the forward urge of said motor upon adjustment of said cam and having an area providing a dwell for said head following said feed and prior to reverse movement of said head.

9. A machine tool combining a fixed head; a head movable relative thereto; a fluid pressure motor for propelling said movable head in forward and reverse directions; abutment means for positively limiting the forward movement of said head; power driven means for adjusting said abutment means to effect a slow feed of said movable head at a positively determined rate under the force of said motor; manual control means for initiating the forward movement of said movable head; automatically operated control means for rendering said power means effective to adjust said abutment 7 means upon engagement thereof; and automatically operated means for reversing said motor and head upon completion of said slow feed.

- 10. A machine tool combining a fixed head; a head movable relative thereto; a fluid pressure motor for propelling said movable head in forward and reverse directions; abutment means for positively limiting the forward movement of said head; selectively operable power driven means for adjusting said abutment means to permit a slow feed of said movable head under the urge of said motor at a positively determined rate; control means for initiating the forward movement of said movable head; means automatically operated at a predetermined point in the forward movement thereof to render said abutment adjusting means effective; and means automatically operated at a predetermined point in the adjustment of said abutment means to reverse said motor and movable head.

-11. A machine tool combining a support; a head translatably mounted thereon; a hydraulic motor for translating said head; fixed abutment means on said 7 support; adjustable abutment means for engaging said fixed abutment means in the translation of said head including a transversely adjustable cam carried by said head, means for adjusting said cam when said abutment means are in engagement by advance of said'head whereby a positively controlled advance of said head is thereafter effected.

ROBERT CERTIFICATE or connection.

Patent No. l. 945, 034.

January 30, 1934.

RQBERT M. GALLOWAY.-

it is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 4, line 133, claim 5, for "abutments" read abutment; and line 135, after "mechanism" insert the words fonadjusting-said cam, and means; and that the said Letters Patent should be. read with these corrections therein that the same may conform to the record of the case in the Patent Oifice.

SignetLand sealed this 13th day of March, A. D. 1934.

(Sea l) F. M. Hopkins Acting Connnissioner of Patents.

M; GALLOWAY.

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