US2638659A - Rail clamp for machine tools - Google Patents

Description

May 19, 1953 J. M. WALTER RAIL CLAMP FOR MACHINE TOOLS Filed Sept. 29, 1948 1N VEN TOR.

ATTORNEYS- Q Q dmv M MLT'EK. BY 4. 44 M Patente'd May 19, 1953 RAIL CLAMP FOR MACHINE TOOLS John M. Walter, Cincinnati, Ohio, assignor to.The

G. A. Gray Company, Cincinnati, Ohio, a corporation of Ohio Application September 29, 1948, Serial No. 51,737

6 Claims. (01. 9 -1) This invention relates to a rail clamp for machine tools, and more particularly to a clamp for clamping the rail with respect to the columns in such machine tools as planers, boring mills and the like.

It has been conventional to provide clamping.

means to clamp the rail to the columns in a desired position of adjustment, but the clamping means has heretofore always been so arranged that the clamping effect was normal to the di' rection of movement of the rail on the columns, and no lateral clamping effect had ever been attained.

It is an object of my present invention, therefore, to provide a novel clamping arrangement in which a lateral clamping effect is obtained in addition to the normal or conventional clamping effect.

It is a further object of my invention there-' fore to achieve this lateral clamping effect by a relatively simple modification of existing clamp-' ing means, whereby the clamping means of the present invention, although more effective than any known heretofore, will be very littlemore expensive than the present types of clamping means.

These and other objects of my invention which will be pointed out hereinafter, or which will become apparent to one skilled in the art as the description proceeds, I accomplish by that cer tain construction and arrangement of parts of which I shall now describe an exemplary embodiment. Reference is made to the drawings forming a part hereof, and in which:

Figure 1 is a horizontal cross-sectional view through the columns of a planar or the like, showing the relation of the rail thereto and illustrating the clamping means.

Figure 2 is a detailed view of one of the clamps in plan with parts in cross-section.

Figure 3 is a fragmentary. vertical cross-sectional view taken on the line 3-3 of Figure 1.

Figure 4 is a fragmentary cross-sectional view taken on the line 4--4 of Figure 3.

I shall first describe so much of the structure of a conventional planar columns and rail and conventional means as is necessary to an understanding of the present invention. Thus, the columns of the machine tool are indicated at I and the rail arranged for travel thereon is indicated at II. Relative movement between the rail II and columns III is accomplished on the cooperating ways Illa and Ila. A portion of the rail indicated generally at I2 enters into a recess between the columns III and contains the actuating mechanism for the rail clamping means. As best seen in Figure 3 there is provided a motor I3 and a speed reducer I4 which drives a threaded shaft I5. The screw I5 engages a nut I6 having a T-shaped head IBa fitting within a boss ll of the cross-bar I8 so as to be non-rotative with respect to the bar I8. The nut is held in place in the boss I1 by meansof a washer I9,

engaging over the shaft I5, pressed against the boss IT by means of a helical spring 20 which bears at its other end against a portion of the rail casting Ill). The end of the shaft I5 as at I5a has a bearingin the portion I Ib.

Asthe shaft I5 rotates the nut I6 will travel along it toward the right or left as seen in Figures 3 and 4, and movement of the nut will carry.

with it the cross bar It. At each end the cross bar I8 engages a lever 2| pivoted in the rail as at 22 so that the rotation of the screw I5 produces rocking of the levers 2I about their pivots 22. Each of the levers 2I is provided with a recess 23 within which is pivotally mounted as at 24 a rocking equalizing member 25 having contact elements 26 and 2'I. The members 26 and 21 engage respectively the push rods 28 and v29 which actuate the clamping members to be described hereinafter. By virtue of the mounting of the member 25 an equal thrust is exerted on the members 28 and 29 when thelever 2| is rocked in a counterclockwise direction, as seen in Figure 3.

Referring now to Figure l, the push rods 28.are

shown as engaging respectively the ends of the levers 30, the other ends of which as at 3I engage the shoulders 32 on the columns. The levers 30 are secured to the rail by means of the screws 33 which are threaded into the rail II. The heads of these screws 33 have a spherical underside at 34 cooperating with a spherical counterbore in the lever 30 and the bore through the lever 30 is oversize so that the lever 30 may rock slightly with respectto its bolt 33, thus the bolt 33; cooperating with the spherical counterbore in the lever 30 provides a ball and socket action. When the motor I3 is energized causing the screw I5 to rotate rocking the lever 2I in a counter-clockwise direction so as to exert a thrust on the push rods 28 (this thrust on the levers 30 being in an upward direction as seen in Figure 1), each of the levers 30 is rocked about its bolt and socket joint so as to produce a downward thrust of the edge 3| against the shoulder 32, thus clamping the rail to the columns. The clamping system thus far described is in all respects conventional.

The clamping means of my invention are thus seen at the upper portion of Figure 1 which in the particular instance illustrated are actuated by the lower push rods 29. While the levers 30 of the conventional type may be considered as levers f the first class, the clamping members 40, according to my invention, may be considered as levers-cf the second class. These levers-have the portions 41 engaging the shoulders 42' of the columns, and they are also provided with the bolts 43 having the ball and socket action- -44, all as described above in connection with the levers 30. The bolts 43 however instead of being threaded into the rail are threaded into the wedge blocks 45. These wedge blocks are disposed in a space between each column and the rail and are constrained to travel. up and. down: with the rail by the guide plates 46. As illustrated these wedge blocks have a straight side 45a arranged to coact with the straight surface on the column, and they have the angular sun"- face-ESZ J arranged to cooperate with the :-angul ar surface 2b on the: rail. Thus, when pressur'e is exerted by the push rods 29 the levers Mi -are rocked about their fulcrum: :at- M and draw the. wedge blocks 45 upwardly. By the :coaction of the surfaceslfiw and 45b ala-teral clamping effect is-al'so attained and, therefore, any lateral play is eliminated.

the drawings: L'have shown an arrangement which has proven sati'sfiactory wl-iere- 2 of the usual 4 clamps are according to my invention. It will be clear that there may be installations where only a single pair of-clamps according to my invention may be required, oritmaybedcs-i'rable a 4-cl'amp arrangements: to all 4 theclamps according to my invention.

It will also becl'ear numerous modifications may be made in details: of construction:- without-departing from the spirit of rnyinvenvention. Itherefore donotintend tobe limited otherwise than asset forth in the claims which fOHUW'.

Having-now f-ully d'escribed myinventiom what li claim as and desire to secureby rictters Patent is:

1; 111a; machine tool having columns and-a nail arranged to: tizaveli thereon; by: means of? co-- operating ways, there being spaces between said columns and rail longitudinallyof the directionof relative movement of said columnsand-1 rail;

spaces shaving: converging side walls in a direction. normal thereto, a pair of clamps flcr clamping said rail-with:v respect. to said columns and each comprisingza lever oilthyssmhdl class having its fulcrum: onone of saidbolumns and the force being: appliedfronrsaid rail; and' th'e: load: comprising-a wedge block disposed iii each said space andse'cuved to: one" of said levers be tween. said fulcrurm and said force; said-wedge blocks, when. force is. :applied to .saidtlevers, ext gagingrsai'di converging walls. to exert a-alateval clamping action between said: co'lumnsrand': rail.

2. In a machine tool having columns and a rail arranged to travel thereon by means of cooperating ways, a pair of clamps for clamping said rail with respect to said columns, each clamp comprising a wedge block between one of said columns and the rail, means secured to said rail and engaging said blocks to constrain said blocks to move with-said rail, a lever secured to each of said'blocks and having a portion engageable with one of said columns, said wedge blocks adapted to exert a wedging action between said columns. and: said rail upon actuation of said levers.

3 13h amachine tcol having columns and a rail arranged to travel thereon by means of cooperating ways, a pair'of clamps for clamping said rail with respectlto said columns, each clamp comprising a wedge block between one of said columns and the rail, means secured to said rail and engaging said blocks to constrain said blocks to: mate with: said'maiip a lever otfxthe :second' class secured to: eachzof: saidbiocks an'dzhaving its: mil-- crumon; one of said columns, the; force benigta'p plied: toeach or saidll'eversafrom thera'i'l, andisaidi wedge blocks constituting the loads and; exerting. al'ateral'sclarmping-action. between said columns and said upon a'ctuaifion' ofsa'id levers-1 4''.. III. tut-machine toolzzhaving cclumnszand: axrail-v arranged; toatravel thereon by mean .0fcooper-ating ways-,. :a firstpair of clamps adjacent the bottom-and at the rear of said rail tor clamping sa id :railywi-th' respectto-saidi columns, each clamp comprsing a wedge block between one oi said columns and the rail, means secured. to-said rail andengaging saidblocks-toconstrain-said-blockstor move.- mth saidrail, alever. secured to-each' ot said blocks andihaving. a-portion' engageable with one of said columns, said wedge blocks adaptedto-exert-a w-edging action between: said colunms and. said railupon actuation ofisaid levers; and an. additional. pair of. clampsadjacent the top and. at the front of said. rail tosecure said rail in cooperation withsaidfirst pair of clamps.

.5.. A.-m'achiI-ietool accordingto claim- 2, whereinmeans are provided-tor equalizing the actuating forces on said levers.

6 vA machine :tool accocding to claim 4,,w-hereintmeanss-areprovided. for equalizing the actuatingv forces on the leversof said first pair of clamps; means. are provided on equalizing the: forces on thesclamps otlsaidladditionalpair, and meansrare provided forequalizing the forces applied, to. said means:-

JOHN M. WALTER Refenences Cited in the file ofthispatent- UNITED -S l?A'I ES* PATENTS Number Name- Date 1 37-33904 Muller July '30; 159 18 1,942,414 Eumsenet'al Jan. 9; 1934* 1 976 17 13 Ca-rd ull'o' Oct. 16; I934 2,649l8'42 Kli'ng Aug. 4, I936 2'jl 7i8di I-Tailenbecket all Jan; 23, -1"40

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