US2444664A - Machine tool - Google Patents

Description

July 6, 1948. F. E. MUNSCHAUER MACHINE TOOL Filed June 1, 1945 /V R y m w c 5 0m mmfibm a mmmmofm mm mw m w Nw/ M jm 1 Em g H m h@ m 7 w. m cm w mm 4% ww w M rm H wm Patented July 6, 1948 rslcs MACHINE TUOL Frederick E. Munschauer, Bufialo, N. Y., assignor to Niagara Machine & Tool Works, Buffalo,

Application June 1, 1945, Serial No. 597,137

Claims. 1

This invention relates to reciprocating work tables for machine tools and the like and particularly to fluid operated tables for machines of this class.

Heretofore in this art definite length limitations have existed which prevented satisfactory fluid operation of reciprocating work tables beyond certain stroke lengths, other factors considered. These limitations arise as a result of natural lateral fiexural deflection of the parts when unusually longcylinders and pistons or piston rods are employed, deflections suflicient in degree to militate against satisfactory operation of hydraulic piston and cylinder constructions which by their nature must have accurate fluid-tight engagement, not only as between the pistons and cylinders but also as between the piston rods and the cylinder heads.

The present invention provides means whereby sturdy, accurate and wholly satisfactor hydraulic operation may be employed at stroke lengths hitherto deemed impractical and unworkable. The general desirability and advantages of hydraulic drives for machine tool and other reciprocating work tables are well established and recognized and the present invention extends the benefits of this expedient to ranges of operation not previously available.

Other objects and advantages of procedure in accordance with the principles of the present invention will occur to those skilled in the arts involved. While a specific example of the practice of the present invention is illustrated in the drawing and described herein by way of example, it is to be understood that the underlying principles are not limited thereto or otherwise than as defined in the appended claims. In the ensuing description, reference will be had to a surface grinder as one specific example of a machine tool wherein the principles of the present invention may be advantageously employed,

In the drawings: I r

Fig. 1 is a longitudinal cross sectional view of one form of the apparatus of the present invention taken on line 1-1 of Fig. 2; and

Fig. 2 is a transverse cross sectional view on the line II-II of Fig. 1.

Figs. 1 and 2 show apparatus for achieving the aims of the present invention by the use of a single piston with a traveling support which is at all times substantially midway between the cylinder head and the other end of the piston, thus giving medial support to the extended piston without interfering with free and full entry of the Y piston into the cylinder at its other limit of in the present application contemplates the pro.

vision of duplicate but opposite piston and cylinder arrangements, one set for pushing the Work table in each direction. One piston and cylinder assembly is shown in elevation in Fig. 1, that be.- ing the right-hand piston. and cylinder arrangement of Fig. 2. The left-hand piston and cylinder arrangement of Fig. 2 is not shown in Fig. 1.

In Figs. 1 and 2 the numeral 66 designates a bed and the numeral til designates a work table which is reciprocable thereon. Referring to Fig. 2, bed 68 has Ways 63 and 84 and work table 65 has complementary longitudinal formations at its under side for free longitudinal movement along bed 60. Depending marginal flanges 66 and El are provided on bed SI for further guiding engagement against the upper marginal longitudinal portions of bed 60. The under side of work table ti! and the upper surface of bed 60 have cooperating well formations 68 and 69, respectively. which house the piston and cylinder assemblies and their accompanying mechanism.

Referring to Fig. 1, a cylinder "til has one of its ends fixed securely to bed 60 as by means of a bracket H adjacent one end of bed 60. The other end of cylinder NJ is likewise securely supported upon bed till as by means of a bracket 12. A piston it has one of its ends secured rigidly to the end of Work table lit by a bracket which is opposite to the end of the bed which supports cylinder Hi. The other free end of piston 14 extends into cylinder 16 and the latter has a suitably packed cylinder head arrangementvas at 16 A bearing 85 is fitted about piston 14 for relative axial sliding movement and bearing has a flanged base 8! for longitudinal movement along bed 60 in a guide groove 82. Bearing 80 is provided with a laterally extending trunnion M which rotatably supports a pinion 85.-

The companion piston for movement of the work table 61 in the opposite direction is designated 88 in Fig. 2 and it is likewise provided with an axially sliding supporting bearing 89 having a flanged base 9d. Retaining rails 9!, 92 and 93 are depicted in Fig. 2.

A rack 95 is fixed to bed 50 and a second rack 98 is fixed to the under side of work table 6|. Pinion is in constant mesh with both of the column, will always be just half of the length of lo the part of the piston projecting from cylinder"- l0, because of the lateral restraint imposed by bearing 85 which is securely guided in bed 60.

The opposite bearing 89 is provided witha similar but opposite pinion and rack-mechanism which is merely designated generally at 9B in Fig.

2, and the description need notbe-duplicated in-- further detail.

What is claimed is:

1. In a machine tool, a bed element, a work table element mounted for. guidedlineal move-1 mentrthereon, and drive meansiorefiecting lineal movement ofsaid worktable element, said drive meanscomprising. a cylindenfixed to oneoisaid elements and piston means secured. at oneend to the othenof. said elements,.the other-endooi said piston-meanszbeing disposed for reciprocation in said cylinder-, means guidingwsaidzpiston means against lateral deflection and slidably engaging the-piston means betweencits ends, gear meanscarried by-theguiding means'for free rotation, a rack fixed to said had element and meshing with said .gear means, and a rack fixed -to said, worktable elernentand meshing with said gear mcans'at the opposite side thereof, whereby said- I guiding -meansautomatically -moves along said bed elementat a-rate having a fixed fractional relation to the'rate of movement'ofthe work table element.

2. a machine -tool, a bedelement; a work table element mounted for 1 guided lineal -move-- ment thereon, and-drive-meansior effecting lineal movementof said-worktable element;--said drive means comprising a cylinder -fixedto one of said elements and piston means secured atone end to the-other of said elements the other endof-saidpiston means being -disposed forreciprocation'in said cylinder, means-guiding said piston meansagainst lateral deflection and-slidably engaging the piston means between its ends,- a pinion carriedby the guiding means for 'free rotation; arack fixed to said bed-element andmeshing with said-.pinion, and a rack fixed to said-work table: element andmeshingwith-said =pinion" at the opposite side thereoi, whereby-said guiding-means automaticallymoves along said bed element at one-half the rate of movement of the work table element 3. In a machine tool, a bed element,-a .wor-ktable element mounted for reciprocation thereon; anda pair of opposed drive means forefiecting alternate lineal movement of said-work table elementin oppositev directions-each: of said drive means comprising a cylinder fixed to one-of said elements and piston means secured at-one-end to the other-.ofsaid elements the otherend of .4 said piston means being disposed for reclproca tion in said cylinder, means guiding said piston means against lateral deflection and slidably engaging the piston means between its ends, gear means carried by the guiding means for free rotation, a rack fixed to said bed element and meshing with said gear means, and a rack fixed to said work. table'element and meshing with said gear means at the opposite side thereof, whereby said guiding means automatically moves along said bed element at a rate having a fixed fractional relation to the rate of movement of the work table element.

4. In a machinevtool, a bed element, a work tableelement mounted for reciprocation thereon, and a pair of opposed drive means for effecting alternate lineal movement of said Work table element in opposite directions, each of said drive means-comprising a cylinder fixed to one of said elements and piston means secured at one end to theother of said elements, the other-endoisaid pistonmeans being disposed for reciprocation .in; said cylinder, means guiding; said piston means.

against lateral deflection and slidably engaging the piston means between-its ends, a, rotatable pinion carried by. the guiding means for free rotation, a rack fixedto said bedelement and meshingwith said pinion-, and a rackqfixedto said work table element .andimeshing with said. pinion at the opposite side thereof, whereby said,

guiding means automatically moves along said bed element at one-half the rate of-movementsof the work table element.-

5. In a machine tool,-ua bed, a work, table mounted. for guided lineal movement. thereon,- and drive means forefiecting-lineal movemen-t oi said work table element, said drive means .com-,- prising a cylinder fixed to said-bed and piston;

means secured at one end to=said-work,table, the

otherend of said piston means. being -disposed.-

for reciprocation in said cylinder, means. guiding said piston means against lateraldeflection and slidably engaging the piston means betweenits ends, gear means carried by the guidingameans:

for free rotation, a rack fixed to said bed and meshing with said gear means,- and a rack fixed; to said Work table andmeshing with said gear means at the opposite side. thereof, wherebysai-d guiding means automatically moves along said bed at a ratehavingafixed. fractional relation to the rate ofmovementof theworktable.

FREDERICK E. MUNSCI-IAUER.

REFERENCES CITED"? Tim-following references-are of. record. in the file of this patent:

UNITED STATES PATENTS."

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