US2585216A - Unitary mechanism for performing multiple simultaneous and successive operations - Google Patents

Description

1952 c. A. BICKEL ET AL 2,585,216

.UNITARY MECHANISM FOR PERFORMING MULTIPLE I ill/ I 1952 -c. A. BICKEL ET AL UNITARY MECHANISM FOR PERFORMING MULTIPLE SIMULTANEIOUS AND SUCCESSIVE OPERATIONS 5 Sheets-Sheet 2 Filed May 7. 1945 Y INVENTORS CLIFFORD ABIEKEI. smmsvnsnmosnsuas- BY THEODORE iEEE TEH & ATTO NEYS Feb. 12, 19 v c. A. BICKEL ET AL 2,585,2i6

UNITARY MECHANISM FOR PERFORMING MULTIPLE SIMULTANEOUS AND SUCCESSIVE OPERATIONS 5 SheetsSheet 5 Filed May 7, 1945 INVENTORS CLIFFORD FL BIEKEL 'ETHNLEY' F1. BRBNDEN BURG- BY THEUDURE FOSTER ATTORNEYS 1952 c. A. BICKEL ETAL 2,585,215

"UNITARY MECHANISM FOR PERFORMING MULTIPLE SIMULTANEOUS AND SUCCESSIVE OPERATIONS 5 Sheets-Sheet 4 Filed May 7, 1945 I NVENTOR S CLIFFU ED H. BICHEL 'ETHNLEY RBRBNDENBUEG THEDDCIRE FUSTEP. WJMW' ATTORN EYS 1952 c. A. BICKEL ET AL 2,585,216

UNITARY MECHANISM FOR PERFORMING MULTIPLE SIMULTANEOUS AND SUCCESSIVE OPERATIONS Filed May 7, 1945 5 Sheets-Sheet 5 JWENTOR. CLIFFORD A B/G/(EL STANLEY/4 BRANDE/VBURG Y THEODORE FOSTER Patented Feb. 12, 1952 UNITARYMECHANISM FOR PERFORMING MULTIPLE SIMULTANEOUS AND SUCCES- SIVE OPERATIONS Cliiford A. Bickel, Stanley A. Brandenburg, and Theodore Foster, Sidney, Ohio, assi'gnors'to The Monarch Machine Tool 00., Sidney, Ohio, a

corporation of Ohio Application aya, 1945, SerialNo. 592,507

In co-pending application Serial No. 584,570, filed March 24, 1945, We have disclosed'a machine adapted for a plurality of uses either'alone or as an attachment to varioustypes of well known machine tools. This machine, in general, comprises a base, a main slide movable on and along the base in straight line motion, and an auxiliary tool-carrying slide supported upon the main slide and movable at right angles to the direction of movement of the main slide, to provide for tool relief movement. A motor is positioned in the base and is connected to drive the main slide through separate selective drives having different speed ratios. The driving motor is reversible. A number of switches are lo'catedon the base in the direction of movement of the main slide, and are positioned to be actuated by respective elements on the slide adjustable in the direction of travel thereof to vary the points in the travel of the slide at which speed changes and reversal occur. In a typical cycle of movement, the motor is started and advances the main slide and cross slide rapidly, until just prior to engagement of the tool with the work. At this time one of the switches is actuated to shift the power drive between motor and slide, from high to low speed whereupon, the main slide immediately slows down and is then advanced at feedin speed during actual operation upon the work. A second switch actuating element is so adjusted as to trip a limit switch at the instant the main slide reaches its maximum desired position of travel to thereby reverse the driving motor. Means including a lost motion connection to the main slide are provided whereby, prior to retraction movement of the main slide, the auxiliary or cross slide is given a movement in a direction to relieve the tool from the work. The main slide is then picked up by the driving motor and rapidly retracted until it again reaches the limit of retraction travel as determined by a third switch and adjustable operating means therefor.

The machine described is extremely flexible and is useful for a great many operations formerly requiring a far more complicated device. Among the possible uses may be mentioned turning, chamfering, facing, drilling, boring, forming and grinding. In addition the machine is useful as an attachment to lathes, planers, boring machines, milling machines and numerous others.

While some of the operations described in the precedin paragraph, are preferably carried out with the use of the cross slide and its provisions for tool relief, others require a straight line move- 9 Claims.

, 2 ment of the tool only, such as drilling. In. order to'provide a single machine that is capable of universal use, we have invented a machine that is provided with a cross, or relief slide that may,

at the option of the user, and by a simple adjustment, be cut into or out of use in accordance with the particular operation it is desired to perform. In this manner, a battery of such machines, all the same, may be set up in'a row to perform successive operations upon a work piece such as a cylinder head.

It is, therefore, an object of our invention to provide a machine as aforesaid, in which the cross slide may be easily and quickly out in or out at will. v

A further object of our invention is" to provide a battery of machines able to turn, drill, form or otherwise treat work pieces such as cylinder heads and so arranged that if any one of the machines is out of operation, it will not entail a complete shutdown of the production line as is the case with large automatic machines capable of performing a multiplicity of operations.

Another object is to provide a battery, of machines as aforesaid in which work operations are successively performed upon work pieces as they move along a production line and wherein the successive machines may be quickly shifted from one operation to another whereby the rate of production may be maintained at a maximum and the piling up of work at one or more points is obviated.

A still further object is to eliminate the use of turrets and multiple turret lathes.

In the drawings:

Figure 1 shows a work table or bench mounting three or more machines as disclosed herein, each machine being positioned adjacent a powerdriven chuck and wherein a plurality of successive operations may be performed upon the work pieces, all machines being serviced by one attendant.

Figure 2 shows a bench or support for a plurality of chucks, each power driven and each adapted to successively receive and rotate a work piece while being operated upon by a tool guided and controlled by a respective one of the machines forming the subject matter of this invention.

Figure 3 is a View of a battery of machines pieces mounted in sequence in jigs secured to the respective machine slides.

Figure 4 is a schematic view showing the alternate power drives for the slides, the electro-magnetic clutches for the two drives, the change gears for the slow speed drive, and the mechanism for rendering the cross or relief slide efiective and ineffective, and

Figure 5 is a wiring diagram showing the electrical control system. H

Referring now to Figure 1, we have shown a. work-bench I generally U-shaped in plan and having an inner shelf 2 lower than the main supporting surface 3 of the bench. Surface 3 carries a number of arbors, journaled in housings 4, 5 and 6, each of which arbo'rs carries a chuck I, 8 and 9, respectively wherein a work piece or tool may be rotatably mounted. The lower shelf by shaft 52. A magnetic brake housing 51 and its coil 51a are fixed to the instrument so that portion 2 of bench supports a number of machines, all of which may be substantially the same so that only one need be described.

As disclosed in our aforesaid copending application, each machine lfi'includes a base It! bolted to shelf 2 and slidably supporting a main slide H extending adjacent a chuck, whereby a work piece held in the chuck may be operated upon by a tool held upon the slide, or vice versa. A motor compartment I2, is fixed with base H1 and carries a motor 36, Figure 4. This motor is connected to drive slide H by means that will presently be described. The ends |3 of three adjustment screws, project from slide H and provide for exact adjustment of the points of reversal of the slide and the point in its forward travel at which its speed is reduced from rapid traverse to feeding.

The mechanism for rotating the screw 29 comprises a motor 36 that is shown in Figure 4 as directly connected to a pinion 31. In mesh with one gear 38a is a compound gear 38 keyed to a shaft 39. Pinion 31 is integral with a short shaft journaled in anti-friction bearings and carried by an end wall of a machine bed on the adjacent wall of a motor housing. 39 is journaled in anti-friction bearings and has fixed to its end a core 44a of an electromagnetic clutch 44. The armature 44b of clutch 44 is shaped as shown in Figure 4 to have a splined bore to receive a correspondingly splined The winding or coil 440- clutching engagement with core 44a whereby shaft 39 is connected to drive shaft 45. An electro-magnetic brake comprises a housing 41 and a coil 41a therein both fixed to the frame of the instrument. Thus when the coil 440 is de-energized and coil 41a is energized, armature 44b is drawn into contact with housing 4'! and shaft 45 is held against rotation. Gear 38?) meshes V with an idler 48 that is fixed on a stub; shaft journaled in antifriction bearings. Gear 48 in turn meshes with and drives a gear 5| keyed to.

a shaft 52 journaled in the frame of the instrument. Shaft 52 has attached thereto a core 54a of an electro-magnetic clutch 54. As in the case of clutch 44, the clutch 54 has an armature 54b having a splined bore to receive a correspondingly splined end of a shaft 55 and a coil 54c fixed with its housing 56 to the frame of the instrument.

Shaft- Upon energization of coil 54c armature 54b is attracted and moved axially into contact with when energized and with coil 54c de-energized, armature 54b and shaft 55 are fixed against rotation. The alternate drives from shafts 45 and 55'to screw 29 will' now be described.

Shaft 45 carries a worm 58 in mesh with a worm gear 59 fixed to shaft 60. A change gear 62 is attached to the outer end of shaft 8|) and meshes with-a change gear 63 in turn fixed to a shaft 64. Shaft 64 carries a worm 65 in mesh -with a gear 66 keyed to a shaft 61 and having fixed thereon a pinion 69 meshing with an idler 1|] journaled upon a stub shaft II. This shaft which is fixed to the casing of the machine also journals a second idler gear 16. It will be noted that the end of shaft 55 carries a bevel pin 1'! forming one side of a differential generally'designated as 18. The frame or planetary element 19 of differential 18 is shaped as shown in crosssection in Figure 4. Thisframe has a sleeve or collar projecting axially of shaft 55 and on which a gear 83 is keyed. This gear meshes with and is adapted to be driven by idler gear -'|0 previously mentioned. The sleeve of frame 19 has bearings rotatably mounting a shaft Shafts 55 and 84 are coaxial and a pinion 85 is fixed to the end of shaft 84 and meshes with and drives gear 16 previously mentioned.

At its other end shaft 84 carries the bevel pin Ila forming another side of the differential. Frame 19 carries the usual planetary pinions Slancl 88 journaled upon a shaft 89 extending diametrically across frame 19 and fixed thereto. For the sake of clarity gear 76 is shown broken into halves and it will be noted that the upper half is shown in mesh with a pinion 9D keyed to a screw shaft 9|. Screw 9| is journaled within the frame of the instrument upon an axis parallel to that of screw 29. A pinion 93 has clutch teeth 93a formed thereon and is journaled upon a plane portion of screw 9|. At its side opposite teeth 93a pinion 93 carries an axially projecting lug 93b extending into the path of lug 94a carried by a sleeve 94 fixed to screw 9|. A ring having a lub 95a is journaled on screw 9| between pinion 93 and collar 94. Screw 9| threadedly engages a nut 96 fixed on an auxiliary slide provided with means to carry a tool or work piece.

As disclosed in the copending application identified, supra, nut 28 is connected to main slide while nut 96 is connected to an auxiliary or relief slide 26 (see Figure 1) that actually carries the tool or work piece and that, upon relative rotation between screws, is moved transversely to remove the cutting edge from contact with the work just prior to rapid retraction of the main slide. This relief movement of the auxiliary slide 26 is effected by the lost motion connection afforded by collar 94 fixed to shaft 9|, and gear 93 journaled upon said shaft, whereby, on reversal of motor 36, shaft 9| is given a limited reverse rotation before shaft 29 is picked up and begins to rotate.

This relief movement of the tool is extremely useful in certain classes of operations such as boring, where the finished surface of the work would be marred and perhaps spoiled, in case the cutting edge of the tool were retracted while in contact therewith. However, in other classes of work, such as drilling, it is desirable to eliminate this relief movement. In order to provide an adjustment whereby the relief movement may be cut into or out of the machine at will, we have provided a clutch element 91 splined to the -non-' threaded portion of. shaft 9|, between gears 96 and 93, and having clutch teeth 91a adapted, in one position of element 91, to engage between teeth 93a of gear 93 and thus lock gear 93 to shaft 9!. Under these conditions, shafts 29 and 9| must rotate in synchronism at all times, and no relief movement of the auxiliary slide is possible. Element 91has a circumferential channel adapted to be engaged by rollers, journaled'in the forked ends of a shifting lever 98, pivoted at 99 to and extending exteriorly of, the machine casing I66. v

The electrical circuit controlling the actuating of the clutches and the reversal of the driving motor is shown at Figure 5. Motor 36 is preferably a three phase machine but may be of any other type adapted to be reversed by means of circuit closers. The direct current supply lines are shown at LI and L2. A is the coil of a contactor connected to be energized upon closing of the switch I69 to thereby close the normally open contacts AI and A2, Figure 5, and start rotation of motor 36 in a predetermined direction.

Contactor coil B is connected to be energized by closure of a cycle start switch I6I through the normally closed contacts CI. Coil B, when energized, closes normally open contacts BI and B2, and opens contacts B3. Contacts CI and switch I9I are by-passed by a line including the normally open contacts BI, inching switch I62, the normally closed contacts of a single pole double throw limit switch I23, normally closed contacts of single pole double throw limit switch I26, the normally closed contacts of single pole double throw switch I 63, and the normally closed contacts-of limit switch I25, to thus establish a holding circuit for coil B. The switch I6I and the normally closed contacts CI are further bypassed by a line I64 that includes the normally closed contacts EI, the normally open contacts F2 and FI, line I18, switch I63, and limit switch Contactor coils C and D are connected across the main lines LI and L2 by a line that includes normally open contacts DI of the contactor coil D, the normally closed contacts of switch I 26, the normally closed contacts of switch I63, and the switch I25. A jogging switch I12 is also connected in series with the coil of contactor C and has normally closed contacts I12a andnormally open contacts I'I2b. Contactor coil C, when energized, closes contacts C2 and C3, and opens con tacts CI, C4 and C5. Contactor coil D, when energized, closes contacts DI.

Contactor coil E controlling normally closed contacts E I, is connected across lines LI and L2 through the normally open contacts C2, previously mentioned. A condenser I14 is connected in parallel With contactor coil E. An adjustable resistor I16, in series with contacts C5, is shunted across the terminals of condenser I14. This condenser arrangement is for the purpose of delaying the energization of contactor coil E for a predetermined time after closure of contacts C2, for a purpose that will be subsequently described.

Contactor coils F and G are connected in parallel across-lines LI and L2 and are adapted to be energized through normally open contacts-FI switch I63 and limit switch I25. Coil B may be shunted by coils F'and G through contacts F2 and EI under conditions subsequently described.

Coil 540 of clutch'54 is adapted to be energized by closure of the normally open contacts B2 of coil B while coil 51a of brake 51 is connected across the lines-byway' of "contactsias. The coil 440 of clutch :44 and coil41a -ofbrake 41are connectedacrossthe lines thr'ough contacts C3 and C4, respectively. Contactor coilG isfor the 'purpose of reversingthe direction of rotation of-motor 36 and, for thisipurpose,controls normally I closed contacts 'GI and G4, and normally open bladesGZ and G3, Figure 5. As shown in'said figure,.when coil G is energized, the several contacts GI to G4, inclusive, act to reverse the phase relation and direction of rotation of the motor 36 in amanner wellknown in the art.

In operation, upon manual closure of switchv I66,.contactor coil A is energized to thereby close contacts AI and A2, Figure 5, and start rotation of motor 36. The operator next closes switch I 6I to energize coil B. .Energization of coil .3 establishes a holding circuit from line LI through switches I25, I63, I26, I21, I.62,:now closed con-. At the same tim'a.

from the motor 36 to the mainslideor-carriage Ii, in the manner previously described. At the:

same time, coil 440 of clutch 44 is de-energized while coil 41a of brake 41 remains energized.

Slide I I new advances at-arelatively rapid rate until movementthereof throws limit switch I21 to its position opposite tothat shown at Figure 5, thus breaking the holdingcircuit to coil B and ole-energizing the same. Thereupon, contacts B2 open and B3 close to de-energize coil 54a and energize coil 51a, thus disconnecting shafts52 L lower contacts'of switch I21, line I66 and coil I D to line L2. As contacts I120, of switch I12 are closed, coil C is also energized, as will be obvious m from inspection of Figure 5. Energization of coil D closes contacts DI and establishes a holding circuit for coils C and D. Energization of coil C opens the contacts CI and C4 and closes contacts C2 and C3. Closing of, contacts C3 and C4 acts to energize coil 440 of clutch 44,1and to'deenergize coil 41a of brake 41, thereby freeing shaft 45 and connecting it to .be driven byshaft 39. The drive from motor 36 to slide II is-now by way of the change gears 62 and 63 and the movement of slide I I continues in the same direction but takes place at a reduced speed. Opening of contacts CI makescertain that inadvertent closure of switch I6I will have no efiect upon coil B at this time. Operation uponthe work piece now takes place until movement of the slide II throws limit switch I26 from the position shown at Figure '5 to a position in which it closes its lower contacts, thereby de-energizingzcoils C and,

way of line LI, switches I25, I63, lower contacts of switch I26, and lines I19 and I80 to coils F and G and line L2. Motor 36 is thus reversed by the ensuing openingof contacts GI and G4, Figure 5, and the closing of contacts G2 and G3. As coil F is energized, contacts FI and F2 are closed.

Contacts FIcomplete a' holding circuit for the I coils and G by way'of line Iil, switch 125,"

switch I63, line l'l8, contacts Fl and coils F and G- to line L2. Contacts F2 completea holding circuit for the coil B. The closing of contacts F2, however; is ineffective to energize the coil B until contactsEl have closed. ,The coil E remains energized for a predetermined time, while the energy stored therein is dissipated through condenser I14 and resistor l'lli. As the latter is adjustable, this time interval is correspondingly adjustable within close limits- Inasmuch as both brake coils are, energized at this time, the slide llis locked in position and dwells for a predetermined length of time determined by the aforementioned time delay'circuit.

At the end of the time delay interval, contactor coil E is de-energized and contacts El close to thereby establish a circuit from line L2 to coil B line I64, contacts El, contacts F2 .and Fl, line I18, switch I63, and switch l to line Ll. Coil B is thereby energized and contacts B2 are closed to energize coil 540 while contacts B3 are opened to de-energize coil 51a. This connects the motor 36 to the slide ll through the high speed drive and-since the motor is "now reversed, the slide l l is rapidly retracted.

As the slide reaches the limit of its retraction stroke, the movement of slide ll opens limit switch I25, thus interrupting the holding circuit for coil B so that contacts B2 open and contacts 33' close. The actuation of switch I25 is also effective to interrupt the holding circuit of coils F and G. De-energization of coil G permits contacts GI and G4 to close while G2 and G3 are opened. This restores the original connections, reverses the motor and causes slide l l to advance upon initiation of a new work stroke.

By operation of push button ll2 feeding movement of the tool into the work may be halted at any time or'the slide may be inched by depressing the blade to momentarily connect terminals ll2b. Switch I63 may be depressed at any time to return the slide ll to its initial position, while switch-I62 may be operated at will during rapid traverse of the slide toward or from the work to inch the same; I

It wilbe understood that limit switches I25, l2liv and l2'l are'fixedly positioned within the motor compartment l2 of the machine and are positioned to be sequentially actuated by elements connected to move with slide ll and adjustable in the direction of movement of said slide by the adjustment screws whose ends are shown at l3, Figure 1.

Figures 2 and 3 illustrate further uses of the invention. In Figure 2, a battery of six machines is shown, mounted upon a bench l4 having an upper shelf l4a provided with T-slots l5, and a lower shelf Mb adapted to have the machine bases In attached thereto. A series of live arbors, each journaled in a'frame or support 5 and each carrying a chuck 8, are shown. Frames 5 are secured in adjusted position upon and along shelf l4a by means of T-head bolts, not shown, having their heads engaging within T-slots l5. As an example of the use to which the machine may be put in performing a series of operations upon a work piece, Figure 2 shows the successive steps in the formation of a special collar;

The circular blank of material is first mounted on a mandrel in the chuck 8 at the left of Figure 2. Two machines lllA and lllB' are shown for operating upon the work piece during this operation. Machine lllA may carry a tool on its slide adapted to f nish the cylindrical surface A of larger diameter, while machine IOB may carry a tool upon its slide adapted to finish the part B of smaller diameter and the sloped or frusto-conical surface connecting the cylindrical surfaces A and B. These operations may be performed slmultaneously or in sequence, as desired, each machine being adjusted to advance its slide to the precise limit of cut desired and then to retract rapidly. It will be noted that machine IA is positioned so that its slide moves axially of the work, while machine lOB is located so that its slide moves normal to the work axis. This illustrates the flexibility of the machine. In the case of machine lllA, the relief slide would normally be used, while in the case of machine lOB, its use is unnecessary.

After the turning operations, the work piece is transferred to the second chuck where the inside corner is chamfered at C by a tool mounted upon the slide of machine I80, the use of the relief slide in this case being unnecessary. The work piece is now transferred to the third chuck, where a single machine lllD. with the relief slide cut out of use, operates to drill a central hole D and to face the annular projection E thereof.

In the fourth chuck the previously drilled center hole is bored as at F to final and finished diameter by a machine IHE, having its slide movable parallel to the work axis. In this operation the relief slide is used to make certain that the cutting edge of the boring tool is out of contact with the finished surface during retraction. Finally, the work piece is mounted in the last or fifth chuckand is turned to form a groove G adjacent its end. Thus the part is completed quickly and easily in a series of operations performed by a number of machines. By connecting the machines and power drive for the chucks for joint control, that is, by providing a master switch connected to start and stop all chucks and all motors 3G simultaneously, a single operator can operate the entire battery of machines. After each step all chucks are opened, and each work piece will be advanced by one step for its next succeeding operation. Thus one operator can produce a large number of finished work pieces per unit time. Furthermore, there is no possibility that a breakdown in one machine will hold up the entire production line as is possible where all operations are performed by a single automatic machine. Figure 2, show that it is possible to double up and combine two operations in a single machine. Or by keeping one or more machines in reserve, any machine of the battery that has to be serviced, can immediately be replaced by a reserve machine adjusted for that particular operation, whereby production may be continued substantially without interruption.

Figure 3 illustrates a bench l6 generally U- shaped in plan and having upper and lower shelves, lGa and H51). A number of grinders lla. Ho, Ho, etc. are secured in desired positions upon the upper shelf to have their wheels projecting over the shoulder l6c, between the shelves for operation upon work pieces held in corresponding onesof a battery of machines as disclosed in the aforementioned co-pending application. By this arrangement a series of grinding operations upon a work piece may be carried out in the same manner as has been explained in connection with the procedure described in connection with Figure 2. All grinders and all of the machines may be simultaneously controlled from a master switch and, with, the set-up shown at Figure 3, eight dif- For example, steps A and B,

ferent operations may be performed simultaneously upon as many workpieces. Because'of the extreme flexibility, adaptability and ease of adjustment and operation of our machine, rapid production of precision is assured while any machine requiring servicing may be immediately replaced by a stand-by. Thus production is maintained at all times and anydanger of stoppages because of a breakdown ofany one or more of the machines, is obviated.

While we have shown the form of our invention now preferred by us, we wish itunderstood that the disclosure is illustrative onlyand not to be taken in a limiting sense. Numerous alterations, modifications and substitutions offequivalent-s will occur to those skilled in this art. Accordingly we reserve all such alterations, modifications and substitutions as fall within the scope of the subjoined claims.

Having now described our inventionjwhat we claim and desire to secure by Letters Patent is:

1. In a machine tool, a bed, a main slide reciprocably guided on said bed, a relief slide reciprocably mounted on said main slide and adapted to support a tool, a motor mounted on i said bed, driving connections between said motor and said slides adapted to move said relief slide a predetermined distance in relief movement and then automatically move said main slide, and a separate driving connection operable to cause said slides to move at all times as a unit.

2. In a machine tool, a bed, a main slide reciprocably guided on said bed for straight line motion in a first direction, a relief slide guided on said main slide for movement in a second direction normal to said first direction, a motor on said bed, first and second parallel screws connected to be driven by said motor, means connecting said screws to operate said slides, respectively, a lost motion connection between said screws whereby said relief slide may be operated prior to said main slide upon reversal of said screws, and a separate connection operable to connect said screws for movement in synchronism, whereby relief movement of said relief slide is eliminated.

3. In a machine tool, a bed, a motor housing carried by said bed, a main slide guided for straight line movement on said bed in one direction, a relief slide guided for straight line movement on said main slide in a second direction substantially normal to said first direction, means controlling the movement of said relief slide, including a pair of parallel screw shafts journaled in said bed and a lost motion connection between said shafts, a motor in said housing, driving connections between said motor and shafts, and a clutch operable at will to positively connect said shafts for rotation in synchronism whereby relief motion of said relief slide is eliminated.

4. In a machine tool, a bed, a first slide guided on said bed for rectilinear movement in a first direction, a second tool-carrying slide mounted on said first slide for relief movement relatively thereto in a second direction normal to said first direction, means controlling relief movement of said second slide, including a first screw shaft journaled on said bed connected to operate said second slide, a second screw shaft journaled on said bed and connected to operate said first slide, a motor carried by said bed, power connections between said motor and said first screw shaft, a lost motion connection between said I screwshafts whereby, on reversal of said first screw shaft, said second slide is operated in relief movement prior to reverse movement of said first slide, and clutch means operable to positively connect said shafts for rotation in synchronism whereby relief movement of said second slide is eliminated.

, 5 In a machine tool, a bed, a main slide guided direction, a tool-carrying relief slide guided on direction, means operable to effect relief movement of said relief slide in said second direction and including a first screw shaft journaled on said bed and connected to drive said relief slide, a motor connected to drive said first screw shaft, a first gear journaled on said first screw :shaft, a second screw shaft journaled on said bed and connected to drive said main slide, a second gear fixed to said second screw shaft and meshing with said first gear, a lost motion connection between said first gear and first screw shaft, a collar splined to said first screw shaft, clutch teeth on said collar and first gear adapted to be brought into and out of mesh by axial movement of said collar, and means for axially moving said collar whereby, when said teeth are in engagement, said lost motion connection is eliminated.

6. In a machine tool, a bed, a main slide guided on and by said bed for translation only in one direction, a cross slide guided on and by said main slide for movement relative to said main slide in a second direction at an angle to said first direction, said cross slide being adapted to carry a cutting tool, a power source fixed with respect to said bed, a first mechanical drive between said source and said cross slide, a-second mechanical drive between said first mechanical drive and said main slide and including a lost motion connection operable to move said main slide only after said cross slide has been moved a predetermined amount at one terminus of motion of said main slide, and clutch means operable to positively interconnect said mechanical drives for movement of said slides in unison whereby said lost motion connection is eliminated.

7. In a machine tool, a bed, a main slide guided for translation on and along said bed in a first direction, a tool slide guided for translation on and along said main slide in a second direction at an angle to said first direction, a motor on said bed, a differential having first and second power input means and power output means, a first drive between said motor and said first power input means of said differential, said first drive including a releasable first clutch, a second drive between said motor and said second power input means of said differential, said second drive including a releasable second clutch, a third drive from the power output means of said differential to said slides, said third drive including a lost motion connection to said main slide, and a fourth drive from said power output means to said slides operable to cause said slides to operate at all times as a unit.

8. In an attachment for machine tools, a bed, a main slide guided on and by said bed for straight line movement in a first direction, a tool slide guided on and by said main slide for straight line movement in a second direction at an angle to said first direction, a screw shaft on said bed for controlling movement of said tool slide in said second direction, a motor carried by said 1,1 bed, a difierential having first and second power input means and power output means, drive connections between said motor and said first and second power input means of said differential, a connection from the power output means of said difierential to said screw shaft, a lost motion connection between said connection and said main slide whereby, upon reversal of said motor, said screw shaft is actuated to effect relief motion of said tool slide priorto initiation of reverse movement of said main slide, and clutch means operable to positively interconnect said slides for movement in unison whereby said lost motion connection is eliminated.

9. In a machine tool, a support, a main slide on 15 tive to said. main slide at one terminus of said main slide, and clutch means operable to positively interconnect said slides for movement in unison whereby said lost motion means is eliminated.

CLIFFORD A. BICKEL.

STANLEY A. BRANDENBURG.

THEODORE FOSTER.

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

UNITED STATES PATENTS Number Name Date 522,930 Church July 10, 1894 1,095,322 Foote May 5, 1914 1,130,277 Hartness Mar. 2, 1915 1,673,088 Potter June 12, 1928 2,002,933 Buell May 28, 1935 2,206,886 Granberg et a1. July 9, 1940

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