US2483535A - Reciprocatory drive for machine tools - Google Patents

Description

Get. 4, 1949. K. F. GALLIMORE 2,433,535

I 'RECIPROCATORY DRIVE FOR MACHINE TOOLS Filed July 31, 1944 2 Sheets-Sheet l I TN mg mglh J7! @aZZz'more 4, 19490 K. F. GALLIMORE 9 95 5 RECIPROCATORY DRIVE FOR MACHINE TOOLS Filed July 51, 1944 2 Sheets-Sheet 2 jieih 1;; GaZZzlm 02 a 9% WM/ Patented Oct. 4, 1949 urnrrno TAT-Es orri .RECIPR'OCAIORgESEFOR :Keith aGallimmi'e, Fond idu Lac, Wis, assignor to Giddings .& (Lewis Machine flinch-(10., Fond du Lac, 1Nis.,=a=-corp0ration of Wisconsin Application liily 3-1, 1944, "SeriaPNo. 547;4s1

4 8 uGlaims. .1

:present invention melates generally rto :imzprovements in le'ciprocatory drives .ior machine :tools, and has particular reference 1012. :new and zirnproved drive orltransmission especially:adapted for Straversingheavy machine'tool omits having :a long range :of movement.

.Onerof :theobjects of :thednvention'is to provide 5a .novel ereciprocatory drive for a .machine :tool unit which is-adaptedrto impart a uniformmoztion, particularly at the points {f .reversal.

Another object :is :to :provide a mew :and improved drive which 'is adapted ;to impart :2. -balanced:for.ce toithemachine-unit soras to-avoid zanyltjendency-of the unit tho :IIOCkiCIQSSWiSe Df'the :guiding means. 1

.A further object :is :to provide ainovel drive of the ioregoing :character adap.ted to translate the unit over a long range :of movement xwitlmiit :requiring ;a supporting "base of :a length :anpre- :eiably :greater than that :necessary to zaccom- .modate the movement.

.A :general object is to provide :a new and aim- .pr.ov.e.d reciproca-tory :drive zfor Eheavy zmaohine .tool'units whichiis simpleiandinexpensivezin coin struction, -=which is sturdy and :reliable in :opera- :tion, and whichireadilyzadjustable to avary the :rate and range of movement.

Gther objects and advantages 'will rbecome 'apparent as the description proceeds.

In the accompanying drawings,

Figure 1 is arfront :elevational view ef a amaichineembodying the .features of .my invention.

Fig. 2is-an end elevational viewzof itheimachine.

Fig. '3 [is ran-enlarged fragmentary plan aview ei the :machine, partially :in horizontal section :to illustrate the drive.

Fig. 4 .is a transverse vertical sectional view taken'along line 4-14 of .Fig. 3.

Fig. 5 is a :diagrammatic representation of the drive and :a reversal control therefor.

Referring more particularly to the drawings, the invention :is adapted :for use generally various types of machines jior traversing rh'e'avy machine unitsadjustably over-an extended range of movement. Such machines may be adapted to performvarious kinds of-rnetalremovingnperations, such for example asmilling orygrin'din g long surfaces.

The invention is particularly useful :for, and hence shown and described :as embodied :in, a machine :for precision grinding hardened steel ways and otherzsuriacesson large machine units, such for :example as :beds, =jco1umns, tables, saddles, rails, etc. Heretofore, machine 'ways ihave commonlyabeemfinished byslowzand itedions hand scraping. The pre'sent machine eliminates these hand operations and their attendant difficulties by finish grinding the ways or 'other surfaces economically and I with a hig'h degree of -accuracy.

'l he :machine'constituting the preferred -em- -bodi'ment Of the irivention comprises an -e'lon- :ga'ted floor plate l adapted 'to support :the work to lbe ma'chined- For example, a machine bed =(not-shown having longitudinal way surfaceson =the to'p to Zbe ground niay be supported in stationarypositiomonthe plate The machine-also comprises a-stationary base structure having an elongated asubbase 2 positioned alongside the il'oo'r pla'te l-, and -'an elox'ig'ated bed 4%, preferably ro'f box-type constr'uction, resting on the sub -base and substantially coextensive in' length therewith. l ke ibed Z3 is formedon the top with suitable spaced parallellongituilinalways 4 and 5 for slidably supporting a reci rocame saddle t. In the present instance, the ways 4 and 5 .are formed salong the marginal edges of the bed t/Jone way 4 ibeingia guiding M -way, and the other way 5 being ia fiat supporting' way. Suitable guards l in the :form @of accordion mellow-s are attached at :op- :posit'e ends to the ends o'f the bed 3 and saddle 6, ;and serves allzposition's 0f the saddle to en- -c10se1the top-surfacesof the bed to protect the .latter sagainst the entry of foreign matter.

Supportedon'one endof the saddle 5 for movement therewith is a vertical column 8 which preferably is rsquare in transverse construction a nd form'ed with ve'rtic'al guiding means at the ifour :corne'rs. A tool supporting arm structure .9 1s mounted on therbolumn a for :vertical adj nstment along the guiding means,-and is suitably counterbalanced-and adaptedtote-adjusted manua'lly by operation 'of a -h a'nd wheel LL and to be :cla-mp'edin slectediaoSitiohof adjustment. The :arm -structure9 iis form'ed with'oppositely extending :rad ijal overarms M and '92 adapted to .be supported selectively in :operative rposition .over ithe 'Ifloor plate A! f-or reciprocation wvith the saddie :5 along the surta'ces .of the workpiece to be frnachined. f-llhe overarm l l supports a motorized roughing t'tool unit orihead l t-which may corn- .prise 'a-la-rge end face grindin-g wheel lo'cated on a vertical axis. ilviountedronitheother overarm #2 :in laterally :spaced :relation :and sfor indepen' ent adjustment longitudinally offthe arm andalso for angular adaiustment :are two itool :units or heads :M sand 1115. Each of the units :55 and 45 comprises awerti'c'al :grin'di'ng spindle 5H5 driven by azmotorzll and havingasgrinding-wheel l8 on'the lower :end adapted "to finish grind the -w0rk -surfaces. a

The present invention relates primarily to a reversible translatory drive for traversing the saddle 6 on the bed 3, and thereby causing the grinding wheels I8 to traverse the surfaces of the work to be ground. In the preferred form, the drive comprises two parallel longitudinal gear racks l9 and 22 mounted in fixed position in the top of the bed 3, and disposed with their teeth in opposed relation. Two suitable gear pinions 23 and 23 are in mesh respectively with the gear racks l9 and 22, and are fixed on the lower ends of two stub shafts 2i and 24 suitably journaled in the saddle 3. To avoid tooth interference, the pinions and 23 and their shafts 21 and 2d are spaced longitudinally of the saddle 6, and are offset with respect to each other transversely of the saddle. The upper ends of the pinion shafts 2i and 2 extend into a gear chamber 25 formed by the webs in the upper portion of the saddle 6 and closed at the top by a removable access plate 26. Secured respectively to the upper ends of the shafts 2i and 24 within the chamber 25 are two worm gears 21 and 28 in mesh at opposite sides respectively with driving worms 29 and 30. Preferably, the worms 29 and 33 are of the hourglass type and formed to provide extensive engagement with the teeth of the worm gears. To permit a close center distance between the shafts 2| and 24, the worm gears 21 and 28 are disposed in difierent horizontal planes so as to permit overlapping of their peripheries.

It will be evident that the rack and gear drive for the saddle is simple and compact in construction. By providing the two rack and pinion assemblies, a strong and balanced drive is obtained. It should also be noted that both rack and pinion assemblies are located in closely spaced relation to the guiding V-way 4 with the result that during the normal translation of the saddle 6, and particularly at the points of reversal of movement, any tendency to rock the saddle crosswise is substantially avoided. Preferably, both racks i3 and 22 are mounted in the top of the bed 3 at the inner side of the way 4, but in closely spaced relation thereto. The innermost rack 22 thus is spaced somewhat further than the other rack [9 from the way t, but due to the compact arrangement permitted by the use of the pinion drive, the racks are located closely together and the unequal spacing in relation to the way does not have any appreciable effect. It is to be understood, however, that the two racks I9 and 22 might be disposed at and along opposite sides of the V-way if an absolutely balanced relationship should be desired.

The drive worms 29 and 30 are, in turn, fixed respectively on two shafts 3| and 32 which extend through the gear chamber 25 transversely of the saddle 6 and which are suitably journaled in bearings supported in the saddle web structure. Provision is made for driving the worms simultaneously in the same direction with a balanced or differential action so that both rack and gear assemblies will act jointly and with equal force to drive the saddle 6. In the present instance, a hydraulic drive is employed, and this drive in its preferred form comprises two rotary hydraulic motors 33 and 34 coupled respectively to the worm shafts 3! and 32. The hydraulic motors may be of any suitable type, such for example as type C-Ml made by the Oilgear Company, of Milwaukee, Wisconsin. These motors are of the reversible constant displacement type, and are flange-mounted on the rear wall of the saddle 6, and disposed with their operating shafts in axial 4 alinement with and directly coupled to the worm shafts 3| and 32.

Any suitable source of fluid under pressure may be provided for supplying fluid reversibly to the motors 33 and 34. In the present instance, the pressure source comprises a rotary pump 35 driven by an electric motor 36, and having discharge and return sides connected in a closed circuit through suitable conduits 37 and 38 in parallel to the intake and exhaust sides of the motors 33 and 34. Both the pump 35 and motor 36 are mounted on the saddle 6 and enclosed in a suitable control housing 39.

The pump 35 may be of the type DX-411 made by the aforesaid Oilgear Company. The details or this pump per se form no part of the present invention and, therefore, are not fully disclosed herein. It is sufiicient to state that the pump 35 has a volume control member 40 which is shiftable through a, central or neutral position defining zero displacement into opposite limit positions defining respectively preset displacements in opposite directions of delivery. The member 40 is operable under the control of valve means adapted to be actuated by solenoids M and 42. Thus, when the solenoid 4! is excited, the pump 35 will be adjusted to deliver fluid through the line 37 to the motors 33 and 34 and receive the return fluid from the motors through the line 38. Consequently, the motors 33 and 33 will operate simultaneously to efiect rotation of the pinions 20 and 23, for example in the direction of the full arrows (Fig. 5) to translate the saddle 6 to the right. Upon energization of the solenoid 42, the pump 35 will be reversed to deliver fluid through the line 38 and receive return fluid through the line 31 so as to operate the motors 33 and 34 in the reverse direction, and thereby eifect rotation of the pinions 20 and 23, for example in the direction of the dotted arrows to translate the saddle 6 to the left. When both solenoids are deenergized, the pump 35 will be adjusted into position of zero displacement, under which condition the saddle 6 will be idle. It will be understood that the rate of travel of the saddle 6 may be varied by adjustably limiting the operative positions of the pump control member 40 so that any preset pump delivery in either direction may be obtained.

By providing two hydraulic motors 33 and 34 of the reversible rotary type, the use of long 001- umns of fluid tending to result in unevenness of travel is obviated, and the extent of saddle movement in both directions is not restricted by any physical limitations of the motors, but can be varied both as to extent and location, restricted only by the'length of the bed 3. If motors of the cylinder and piston type were employed, they would be mounted within and extend longitudinally of the bed, and for a, given maximum length of travel would require the bed to be provided with a greatly increased overall length.

The two hydraulic motors 33 and 34, being connected to receive fluid under pressure in parallel from the pump 35, and being connected through like parallel gear reduction drives to the rack and pinion assemblies, serve to exercise a differential action so that the pinions will exert substantially the same thrust against their respective racks I 9 and 22 to share and equalize the load, and at the same time any slight irregularities or unevenness that may be present in the gear teeth of the racks and pinions will be compensated for.

Provision is made for effecting automatic re- 'trol housing 39. rotationin synchronism withthetranslation of thei-saddle-fi, and tothis end is driven from the mas es :versal of the pump .35Jto reciprocate ltheisaddle 6 through -a predetermined adjustable range.

This means comprisesa rotary control disk 43 mounted on .-a shaft projecting :from the con- The shaft .44 connected for example 300, for translation of the saddle 6 through its maximum range ofmovement.

Adjustably mounted on thelcontrol disk43 are two reversing stops or dogs '49 and 50 adapted for engagement-alternately and respectivelyupon movement of the saddle 6 in opposite directions with-a switch operating lever L This lever is .mounted for swinging movement at the rear of the control disk 83 in the path of the dogs 49 and 50, and has an operating shaft 52 for actuating a limit switch ES controlling the selective-excitation of the valve solenoids 4| and 42.

In operation, at the end of the movement of the saddle 6 in one direction into one predetermined position, the dog 69 will engage the switch lever 5! to initiate swinging movement of the latter into one extreme position, for example as shown in Fig. 5. .A suitable over-center device (not shown) is provided ifor-completin'g the movement of the lever 5i witha snap action. In this position, a circuit is completed for the solenoid -42 from a suitable source of electric current through a line 54, one contact 55 of the switch'53, a line 56, the solenoid 42, andaline 5-1. Consequently, the pump adjusting member 4%] will be actuated through neutral into one adjustable limited orpresetpositionlto reverse the delivery of the pump 35 and thereby effect reversal of the saddle 6. Upon movement of the saddle 5 in the opposite direction intoanother predetermined position, the other dog .59 will engage the switch lever 5| to initiate swinging movement of the latter into its opposite extreme position. The lever 5i thereupon will reverse the switch 53 to deenergize the solenoid 42 and energize the solenoid M, the circuit being completed from the source through the line 54, the contact 58 of the switch 53, a line 59, the solenoid 4 I, and the line 5'1. Consequently, the pump adjusting member 40 will again be shifted through neutral into its opposite adjustable limit position to reverse the delivery of the pump, and thereby the direction of translation of the saddle 6.

With the control as shown, the saddle 6 will continue to reciprocate back and forth and, for each reciprocation, the total head may be manually adjusted downwardly in a feed increment. To stop the reciprocation when the work surface has been ground to the desired depth, or for any other purpose, the operator need merely shift the lever 51 into central and neutral position, thereby opening the switch 53 and permitting the pump adjusting member 40 to adjust the pump for zero displacement. A positive latching device may be provided for securing the lever 5| releasably in stop position.

It will be evident that I have provided a new and improved hydraulically actuated reciprocatory drive which is simple and compact in construction, and which is sturdy and reliable in operation and adapted to impart a balanced double thrust to the machine unit to be reciprocated. By arranging the drive in the immediate proximity of the guiding means for the :machine any side thrust against the guiding means is substantially avoided. Theihydraulic drive provides an equalizing 'force :adapted to compensate for any .mi-nor irregularities Iin the mechanical gear transmissions so that'the machine unit-is operated uniformly and smoothly. Byemployingrotary hydraulic motors, longcolumns of fluid under :pressure with their attendant "difficulties are.avoided,so that thesaddle will be translated :and reversed smoothly.

ll claim: asi-myv invention ,1.. A.reciprocator-y drive .for a;transl-ator machine unit slidable on an elongated bed having a longitudinal guideway, said-drive comprising, in'combination, twoiclosely spaced parallel opositely facingzlongitudinal gearracks mounted on said bedadjacent to and alongside said guide- .way, two vertical shafts ljournaled in said unit and having drive pinions secured thereto and meshing respectively with said racks, two-transverse shafts journaled in-and extending crosswise of said unit, worm and worm gear assemblies respectively connecting said transverse shafts to said vertical shafts, two reversiblerotary hydraulic motors :mounted on said unit and coupled respectively .to said shafts, a reversible variable delivery pump mounted on said unit and connected iin a closed circuit in parallel with said motors whereby to rotate said "motors in the same direction, said worm and-worm gear assemblies *being operable by said motors to rotate said vertical shafts relatively in opposite directions, and control means movable in synchronism with said unit and operable automatically to :reverse the-delivery-of said pump upon movement of said unit respectively in opposite directions into predetermined positions of reversal.

2. A reciprocator drive for a translatory machine unit slidable on an elongated bed having a longitudinal guideway, said drive comprising, in combination, :two parallel longitudinal gear racksmountedon said bedadjacent to andalongside said guideway, two pinion shafts journaled in said unit and having drive pinions secured thereto and meshing respectively with said racks, two drive shafts journaled in and extending crosswise of said unit, worm and worm gear assemblies respectively connecting said drive shafts to said pinion shafts, two reversible rotary hydraulic motors mounted on said unit and coupled respectively to said shafts, a reversible variable delivery pump connected in parallel to said motors, and control means movable in synchronism with said unit and operable automatically to reverse the delivery of said pump upon movement of said unit respectively in opposite directions into predetermined positions of reversal.

3. A reciprocatory drive for a translatory machine unit slidable on an elongated bed having a longitudinal guideway, said drive comprising, in combination, two parallel longitudinal gear racks mounted on said bed adjacent to and alongside said guideway, two pinion shafts journaled in said unit and having drive pinions secured thereto and meshing respectively with said racks, two reversible rotary hydraulic motors operatively connected respectively to drive said shafts, and means for supplying fluid under pressure reversibly and in parallel to said motors.

4. A reciprocatory drive for a translatory machine unit comprising, in combination with an elongated bed having longitudinal guide means thereon, two spaced parallel oppositely facing longitudinal gear racks mounted on said bed adjacent to and alongside said guide means, two vertical shafts journaled in said unit and having drive pinions secured thereto and meshing respectively with said racks, hydraulic motor means of the rotary type mounted on said unit and peratively connected to drive said shafts reversibly and relatively in opposite directions with a differential action, and means for supplying fluid under pressure reversibly to said motor means.

5. A reciprocatory drive for a translatory machine unit comprising, in combination with an elongated bed having longitudinal guide means thereon for said unit, two parallel longitudinal gear racks mounted on said bed adjacent to and alongside said guide means, two shafts journaled in said unit and having drive pinions secured thereto and meshing respectively with said racks, hydraulic motor means of the rotary type mounted on said unit and operatively connected to drive said shafts reversibly and relatively in opposite directions with a differential action, and means for supplying fluid under pressure reversibly to said motor means.

6. A reciprocatory drive for a translatory machine unit comprising, in combination with an elongated bed having longitudinal guide means for said unit, dual mechanical drive means connected in parallel to translate said unit reversibly along said guide means, two rotary hydraulic motors respectively connected to operate said drive means jointly with a differential balanced action, and a reversible variable delivery pump connected in parallel in a closed circuit with said motors to supply fluid under pressure reversibly to the latter and thereby to efiect reciprocation of said unit in opposite directions, and means operable in response to movement of said unit into its opposite end positions to reverse the delivery of said pump.

7. A reciprocatory drive for a translatory machine unit comprising, in combination with an elongated bed having longitudinal guide means for said unit, dual mechanical drive means con- '8 nected in parallel to translate said unit reversibly along said guide means, rotary hydraulic motor means respectively connected to operate said drive means jointly with a differential balanced action, and a reversible variable delivery pump connected to supply fluid under pressure reversibly to said motor means and thereby effect reciprocation of said unit in opposite directions, and means operable in response to movement of said unit into its opposite end positions to reverse the delivery of said pump.

8. A reciprocatory drive for a translatory machine element slidable on an elongated bed having a longitudinal guide way, said drive comprising, in combination, two closely spaced parallel oppositely facing longitudinal gear racks mounted on said bed adjacent to and alongside said guide- Way, two vertical shafts journaled in said unit and having drive pinions secured thereto and meshing respectively with said racks, and two drive motors mounted on said unit and operatively coupled respectively to said shafts to rotate said pinions respectively in opposite directions, whereby the side pressures between said racks and said pinions are balanced.

KEITH F. GALLIMORE.

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

UNITED STATES PATENTS Number Name Date 1,671,323 Cole et al Feb. 2, 1926 1,912,060 Beattie et al. May 30, 1933 1,990,237 Lloyd Feb. 5, 1935 2,033,406 Vancil et a1 Mar. 10, 1936 2,118,489 Carter May 24, 1938 2,120,196 Wright June '7, 1938 2,303,639 Herfurth et al Dec. 1, 1942 2,336,911 Zimmermann Dec. 14, 1943 2,360,671 Haas et al. Oct. 17, 1944

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