US2574687A - Control - Google Patents

Description

Nov. 13, 1951 m m 2,574,687

CONTROL Filed Sept. 7, 1946 -%.IHAIN$N TOR. l

Patented Nov. 13, 1951 CONTROL Edward P. Bullard, III, Fa

t The Bo ard C p Connecticut irfield, Conn, assignor any, a corporation of Application September 7, 1946, Serial No. 695,533 3 Claims. (Cl. 175-335) This invention relates to machine tools, and particularly to a manually-operated control for effecting selected speed-changes of a rotating part in a machine tool.

Ob ects of the invention include the provision of a manually-operated control for a rotatable part of a machine tool, freely suspended in space and easily accessible to an operator; the provision of such a control in which as many as twenty speed changes can be effected by turning a single rotatable lever through 360; th provision of such a control in which numerous solenoids are adapted to be energized in different groups of predetermined solenoids each to effect a greater number of speed changes in a transmission than 7.

e e are s l n ids for efi tins such chan es; the provision of a penda t co t l or the headstock of a machine tool; the provision of such a pendant control in which a single, rotatable shaft within the pendant includes as many cams thereon as there are solenoids to be operated and so arranged that the cams cooperate to close combinations of switches to energize the solenoids in groups of pro-determined solenoids each; the provision of such a pendant control for operating headstock gear-shifting solenoids in which a rotatable member for selectively actuating a plurality of switches is combined with a single, switch actuator for a solenoid adapted to eifect operation of a headstock clutch and brake; and the provision of an interlock between the rotatable switch actuating'member and the single switch actuator so that the former cannot be rotated when the latter is in a pre-determined position.

a The above, as well as other objects and novel features of the invention, will become apparent from the following specification and accompanying drawing, in which:

Figure 1 is a front elevational view of a vertical turret lathe to which the principles of the invention have been applied; and

Fig. 2 is a schematic wiring diagram of an electrical circuit employed in the practice of the invention.

Referring to Fig. 1 the invention is shown as applied to a vertical turret lathe including a base 30 in which the spindle of a work-supporting table 3! is journaled. A standard 32 extends vertically behind the table 3| from the base 310 and includes vertical ways 33, 34 along which a cross rail 35 is adapted to be reciprocated in a vertical plane. A saddle 36 is mountedon the cross rail 35 and is adapted to be moved horizontally therealong by the action of a screw 31 thatis caused to be rotated in both directions by ieedworks transmission 38. A slide 39 is mounted on the saddle 36 for vertical motion through the action of a splined shaft 40 that is also driven through the transmission 38. A turret 4| for supporting tools is'mounted on the slide 39, and from the foregoing it is evident that tools mounted thereon can be moved relatively to work mounted for rotation on table 3|.

A better understanding of the details so far described can be obtained from Patent 2,384,809 granted in the name of E. P. Bullard, III, et al. The "feedworks 38 is driven from a headstock transmission that rotates table 3|, and which is shown and described in the above-identified patent. The headstock transmission of said patent includes sliding change-speed gears that are adapted to produce twenty different rates of rotation of the table 3| upon the selective actuation of nine hydraulic control valves that are operated by a rotatable drum as clearly disclosed in said patent. A tenth valve described in said patent controls the operation of a clutch and brake for the headstock. In the present invention, ten valves similar to those in said patent are adapted selectively to be operated by ten solenoids, A, B, C, D, E, F, G, H, I and J, for setting up twenty d fferent rates of rotation of the work-supporting table 3| and for operating a clutch and brake therefor.

Referring to F g. 2, solenoids A to I inclusive provide t e sear change in the h a k transmission ior table 3!, while solenoid J effects operation of the clutch and brake for said transmission. The solenoids A to J inclusive may be located at any convenient point of the machine tool, but preferably are positioned within a housingcontaining the hydraulic control valves which they ar a apted t op at S e ive r zetion of the solenoids A to J is effected, in accordfe e i h e princip es o e sent i ntion y operatin a con rol t a. poi t in cl se pro imity to the wor able 3 that th o a r as free. access the eto as Well as to he ork; o table .31. The. contr l de i e fo p a i g .6- noids A to J is in the fo m. of a fre ly suspende pendant or housin 42 of box-like. constructio t ched to the end of .a flexible c ndui 43 tha extends upwardly through a hollow tube 44 pivotally attached to the. top .of the standard 32.

The boxe'like pendant .42 is. adapted to support make-and-break switches A to J, one fo each of the solenoi A to J. It also u por shaft 45 having cams 46 to 54 thereon for closing switches A to I in accordance with a predetermined order so that twenty different groups bination of groups of solenoids A to I for pro-. 3 ducing twenty difierent combinationsis as folw A, C, ,;H;-' A; C;'I;;' i;1. A, D, G; A, D, H; A, D, I; BI'QF'; B, C,G; B, C, H,"

C. I; B. D, I; E. F;

E, G; E, H; E, I. From the foregoing; it is evi 4 to be energized. Accordingly, cam 54 is provided with an effective portion 80 that maintains switch E closed when index 56 is in positions 17, 18, 19 and 20. Finally, the last four combinations require the successive energization of solenoids F, G, H and I, and, cams 41, 49, 5| and 53 are provided with points 81, 82, 83 and 84 that successively close switches F, G, H and I when index 56 is successively in positions 17, 18,

19 and 20.

When the pendant control is employed to en- .-ergize solenoids that control the speed changes of a work-supporting spindle, as is the present case, a clutch and-brake must be operated bedent that solenoid A is energized ir1 th e first 3 eight combinations. Accordingly, cam 55 on' shaft, 45 isprovided withan effective. portion 58 adapted to close switch A during the first eight positions of the pointer 56, namely, from position 1 to' position 8. The first four combinations require solenoid C to be energized. Accordingly,

the cam 58 is provided with an effective portion 59 that maintains switchC closed d'uringthe first four'positions of. pointer 56. 'These first I four combinations also require solenoids F, G, H

, and I to be energized successively. Accordingly,

cams 51, 49, 5! and 53 are provided with effective j portions 68, 81, 62 and 53 that successively close switches F, G, H and'I during the first four positions of pointer 55.

The second four combinations require solenoid D to be energized. Accordingly, cam 52 is provided with an effective portion fi l that maintains switch Dclosed during the second four move- 'ments of indicator 55, namely, from position 5 to position 8. The secondfour combinations also require the successive re-energization of solenoids F, G, H and I. Accordingly,- cams d1, d9, 51 and 5:) are provided with effective portions 65, 55, 67 and 58 that successively close switches F, G, II

and I when indicator 5c is at positions 5, 6, 7

and 8, respectively. The combinations repreisented by positions 9 to 16 of the index 55 require the energization of solenoid B. Accordingly, cam 48is provided with an effective portion 59 that maintains switch B closed when index 5 5c is at any of positions 9 to 16. The third four; combinationsalso require solenoid C to be ener- 'gized. Accordingly, cam 58 is provided with a second effective portion HI-that maintains switch C closed when index 55 is at positions 9,*10, -11 and 12. tions require the successive energization of solenoids F, G, H and I, and for this reason cams "41, 49, 51 and 53 include additional effective points ll, 12, i3 and 14 that successively close switches F, G, H and I when index 56 is re--; 60

spectively at positions 9, 10, 11 and 12.

The fourth four combinations represented by positions 13, 14,15 and 15 of the index 58 not only require solenoid B to be energized but also solenoid D. Therefore, cam 52 includes a second-;.

effective portion 15 that maintains switch D closed when index 55 is in positions 13,14, 15 and 16. Additionally, these four combinations require the successive .energization of solenoids F, G, H and I. For this reason, cams d1, 35, 5! and 53 include additional effective portions 15, H, 18 and 19 that successively close switches F; G, H and I when index 58 is-successively' in positions 13, 14, 15 and 16. a

- r The last four combinations requiresolenoid E Additionally, the third four com'bina-q.

i supporting spindle prior to making a change, and

to re-engage said headstock and spindle after a new rate" of speed has been initiated. The solenoid J is employed to operate a hydraulic valve similar to the one employed in the above-referred-to patent that controls the action of the clutch and brake in that case. The switch J is adapted manually to be closed by a toggle switch lever including a cam disc 86 that cooperates with the switch J. It is important, however, that the shaft 45 be interlocked with the switch J so that a different speed rate is not initiated when the headstock is clutched to the work-supporting table 3!. Accordingly, a ratchet 81 is fixed to shaft 45 and includes twenty teeth adapted to cooperate with a detent 88 that is spring-urged into engagement with said teeth. A-draw'bar 89 is attached to the cam 85 and is adapted to reciprocate upon operation of switch lever 85 such that it permits detent 88 to descend when switch J is open, but prevents such action when switch J is closed. From the foregoing 'it'is evident that shaft 45 can be rotated only when switch J is closed and hence work table 3i de-clutched from the headstock transmission. Although the various features of the improved control mechanism have been shown and described in detail to fully disclose one embodiment of the invention, it will beevident that numerous changes may be made in such details, and certain "features can be used without others, without de- -parting from the principles of the invention. 'What is claimed is:

1. In a machine tool, nine solenoids adapted to be energized in different combinations of predetermined solenoids each to provide twenty' different combinations; nine switches, one for each of said solenoids; a cam shaft adapted to be moved to twenty different angular positions 'in' one revolution; four cams on said cam shaft, 'each having five effective portions so arranged that four of said switches are closed in succession five times during the movement ofsaid cam shaft to its twenty positions; two cams on said cam shaft having effective portions for respectively maintaining two of said switches closed during the first and second eight positions to which said cam shaft can be moved; two additional cams on said cam shaft, each having effective portions for maintaining two of said switches closed alterfnately during the first, second, third and fourth four positions to which said cam shaft is adapted to be moved; and a single cam on said cam shaft having an effective portion for maintaining one of said switches closed during the last four positions to which said cam shaft is adapted to be jmoved.

2.In a machine tool, a plurality of solenoids for-controlling the rate of 'rotation' of a rotatable member within said machine tool; a housing adjacent the rotatable member of said machine tool; a plurality of switches within said housing, one for each of said solenoids; a cam shaft within said housing including cams for closing all except one of said switches; a handle for rotating said cam shaft; means for manually operating the switch not affected by said cam shaft; and means between said manually-operable means and said cam shaft for preventing the latters rotation except when said manually-operable means is in a pre-determined position.

3. In a machine tool, a plurality of solenoids adapted to be energized in certain groups to provide more combinations than there are solenoids; a housing in close proximity to said machine tool so as to be freely accessible to an operator; a plurality of switches in said housing, one for each of said solenoids; a cam shaft within said housing, adapted to be moved to as many angular positions in one revolution thereof as there are desired combinations of solenoids to be energized; a plurality of cams on said cam shaft, each having effective portions so arranged that all except one of said switches are closed in accordance with a pre-determined order during the movement of said cam shaft through one revolution; a manually-operable lever on said housing for operating the switch not affected by said cam shaft; and means between said lever and said cam shaft to prevent the latters rotation when said lever is in a pre-determined position.

EDWARD P. BULLARD, III.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,193,250 Gorman Aug. 1, 1916 2,250,847 Torkelson July 29, 1941 2,339,435 Stephan Jan. 18, 1944 2,384,809 Bullard Sept. 18, 1945 2,398,007 Hunter Apr. 9, 1946 FOREIGN PATENTS Number Country Date 539,586 Great Britain Sept. 17, 1941

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