US2331381A - Profile grinding machine - Google Patents

Description

Oct. 12, 1943. J. w. EKSTEDT PROFILE GRINDING MACHINE Filed Oct. 15, 1941 2 Sheets-Sheet l h v v E 0N 5 i.|1e 0.

M l o b. mm oo M mm t lNVENTOR John WE BY f AGENT Oct. 12, 1943. J. w. EKSTEDT I PROFILE GRINDING MACHINE 2 Sheets$heet 2 Filed 001}. 15, 1941 INVENTOR .foim PIKE/vied! BY AGEN nut l6.

T'atented Oct. 12, 1943 PROFILE GRINDING MACHINE John W. Ekstedt. Union, N. J., assignor to General Tool & Manufacturing Company, a corporation of New Jersey Application October 15, 1941, Serial No. 415.019

12 Claims.

The present invention relates to a grinding machine and in particular to a new and improved means for grinding tools by the aid of a pattern.

In the manufacture of drawn articles, in particular cartridge shells; bullet jackets and the like, suitable tools such as punches and dies are used, the profiles of which must be shaped to a specified contour within extremely small tolerances.

It is an object of this invention to provide an improved grinding machine for speedily and accurately profiling tools, such as punches and die shaping reamers. A further object of the invention is to provide grinding means for profiling a tool in conformity with the contour of a pattern. A further object is to provide a grinding fixture comprising unitary means supporting a fixed pattern and a rotating tool blank freely movable over a table provided with motion limiting stops. A still further object is to provide a grinding fixture having gauge means for setting the tool blank relative to the pattern.

Other improvements, features and advantages of the invention will be manifested in the description and drawings which exemplify one form of the invention, but it will be understood that variations are embodied within the scope of the appended claims.

In the drawings:

Fig. 1 is a front elevation of the grinding machine.

Fig. 2 is an end elevation of the grinding machine including a sectional view of the grinding fixture on line 2-2 of Fig. 1.

Fig. 3 is an elevation of the gauge plate on line 33 of Fig. 1, showing the work piece and pattern in contact with the gauge.

Fig. 4 is a side elevation of a dressing tool mounted on the fixture.

Referring to Fig. 1, a grinding wheel I is mounted on the free end of a horizontally disposed shaft ll rotatable at its opposite end in a pair of bearings I2l2 supported in a stock l3 suitably bolted or otherwise secured to a frame [4. The wheel I0 is secured to rotate with the shaft II by a flanged collar I5 and locking H is a stepped pulley adapted to be driven by a suitable belt connected to a power source. Although one grinding wheel is shown, it will be understood that two or more wheels are contemplated, one being used for roughing purposes and the other for a finished grinding; that the wheel It may be a cutter or any other suitable shaping means; and that any other suitable or equivalent means may be used for rotatably supporting the wheels.

The grinding fixture comprises the work unit hereinafter described and a supporting member therefor, the latter being an L-shaped table 20 having leg portions l8 and H3. The leg I8 is secured to the frame I4 at one side of the grinding wheel I0, and is suitably elevated above the frame by spacer blocks IS. The leg l8 projects forwardly of the frame l4 and extends laterally so as to afford a table surface opposite the periphery of the grinding wheel. Beneath the table portion It is secured a pair of parallel gib members 2l-2| extending from front to rear of the table 20 and substantially in line with the plane of the face of the grinding wheel. The gib members constitute guides for supporting a slidable member or bar 22 having a substantially vertical, planar; hardened steel surface 23 integrally formed or otherwise secured at its end adjacent the periphery of the grinding wheel. The planar surface 23 has two functions, namely to act as an adjustable stop means adapted to be engaged by the end of a pattern during the guiding of the work piece as hereinafter described and to constitute an adjustable stop for guiding a dressing tool 29 in the manner indicated in Fig. 4. The opposite end of the slidable bar 22 is suitably secured to the end of an adjusting screw 25 threadedly engaged adjacent its opposite end in a hole in a plate 26 which is fastened by bolts 21 to the front edge of the table 20. It will be clear that by turning the knurled head of the adjusting screw 25, the bar 22 may be made to slide backwardly or forwardly in the guides 2|2l whereby the planar surface 23 may be adjusted relative to a vertical plane tangen tial to the periphery of the grinding wheel. The slidable bar 22 may be readily locked in the guides by a suitable locking screw 28.

The member for supporting the tool blank and the master punch or pattern is hereinafter termed the work unit" and comprises a block 30 having a pair of laterally extending flange portions 3|3l at the base thereof and surmounted by a pair of axially aligned spaced collars 32-32 having bearings 33,34 adapted to support a horizontally disposed tubular spindle 35. The bearing 34 is extended rearwardly, as shown in Fig. 2, and provided with a threaded end 34' to which a coupling 36 is secured. The coupling 33 is adapted, in a well-known manner, for coupling the usual type of flexible drive shaft 31 to the slotted end 35' of the tubular spindle 35. 38 represents the tool blank, hereinafter termed the work piece, concentrically mounted in the spindle 35 and locked thereto by a slightly tapered centralizing bushing or collet 33 which is slipped on the rear end of. the work piece and wedged between the latter and the tapered inner walls of the spindle 35. It will be understood that by this construction a substantial portion of the shank of the work piece is clear of the walls of the tubular spindle 35. This structural feature is particnlarLv advantageous when adjusting the work piece both longitudinally and concentrically relative to the spindle.

The means for supporting the forward end of the work piece comprises a circular plate 40, hereinafter termed a steady-rest. secured to the face of one of the collars 32 by suitable means, such as screws 40' and provided with a radial slot 4| adapted to accommodate a bronze jaw 42 secured therein by a screw 43. The inner end of the jaw 32 is arcuate and is adapted to be adjusted radially to contact the shank portion of the work piece in order to overcome any eccentricity or vibration set up in the latter due to rotation thereof.

The tubular spindle 35 is restrained against endwise displacement in the bushings 33 and 33 by suitable means engaging the inner faces of collars 32. Such means may be a hardened steel pulley M keyed by a screw 45 to the spindle at substantially the mid-portion thereof and rotatable between a pair of bronze thrust washers 46-45 suitably secured on the inner faces of the spaced collars 32-32. Although bronze washers are specified it will be understood that any other suitable material may be used. The tubular spindle may thus be driven either by the fiexible shaft 31 or by a belt running over the steel pulley 3. Suitable oil holes 4'|4| are provided for supplying oil to the spindle.

The master punch 49, hereinafter termed the pattern, is adjustably mounted in a longitudinal hole 50 drilled through the block 30 immediately below the work piece 33 and in substantially the vertical plane thereof. The drilled hole 50 is made sufficiently large so that the pattern may move freely therein, and means are provided for accurately positioning and holding the pattern. Such means may comprise hardened steel end plates |5| adjacent opposite ends of the hole 50 and secured to the respective ends of the block 30 by screw bolts 52 passing through longitudinal slots 52' in the plates. Each plate 5| is provided with a centrally drilled and ground hole 53 in which one end of the pattern is supported, the size of the drilled holes 53 being such that the shank portion of the pattern makes a tight fit therein. Suitable locking means such as the set screw 5| may be provided for locking the pattern against longitudinal displacement in the end plates. Each end plate 5| is adapted to be adjusted laterally by adjusting screws 5354 suitably supported in studs 54'5| fixed on the adjacent flanged portions 3| of the block 30 and adapted to bear against opposite ends of the plate 5|. By this construction the pattern 49 may be set in perfect vertical alignment with the work piece.

The work unit or block 30 is adapted to move freely over the surface of the table 20 and to this end the bottom of the block is provided with hardened steel bearing surfaces 55. Although substantially flat surfaces are shown it will be understood that spherical surfaces or roller bearings may be used.

It will be clear that since the work piece is continuously rotated it is only necessary for the operator to pivot the work unit through an arc of substantially in order to completely profile the end of the work piece and hence suitable stops are supported on the table for limiting the pivotal movement of the work unit, about the point of contact of the pattern with the stop plate 23, to one quadrant of a circle or substantially 90. In its initial position the work unit or block 30 is mounted on the table 23 with the left hand fiange 3| of the block abutting a pair of limit stops 56 suitably fixed to the edge of the table, the stops being adjusted to limit the displacement of the work unit to the left, as seen in Fig. 1, so that the work piece and pattern lie substantially in the vertical plane of the grinding wheel. The work unit is limited in its angular displacement from its initial position to a final position by fixed stop means shown in Fig. 2 comprising a laterally adjustable pin 51 supported above the leg portion [3 of the table 20 by a lever 58 pivotally supported on a standard 59 bolted to the adjacent rear edge of the table.

Referring to Fig. 3, a suitable device is shown for making the initial adjustment of the work piece and pattern. It will be understood by those skilled in the art that an initial allowance for grinding must be made when adjusting the work piece relative to the pattern, and to this end suitable gauge plates or surfaces 5D5| are integrally formed on the standard 55, the surface 60 being set back from the plane of the surface 6| by an amount substantially equal to the allowance necessary for grinding.

In setting up the work unit the work piece is first inserted in the tubular spindle 35. The pattern is then inserted in the holes of the spaced plates 5| and adjusted laterally by the adjusting screws 54 until the work piece and pattern lie in exactly the same vertical plane. Thereafter the work unit is moved over the standard 58 so that the work piece and pattern are substantially perpendicular to the plane of the surfaces 60 and 6| respectively, the end of the pattern being brought into contact with the surface 5|. While the unit is in this position the work piece is moved longitudinally until its end contacts the surface 60, whereupon the work piece is locked to the rotatable spindle by the collet 39 as described above.

In operating the machine the operator moves the work unit over the surface of the table toward the grinding wheel with the left hand flange 3| of the block abutting the stops 56. As the grinding of the work piece progresses the end of the pattern comes in contact with the adjustable stop surface 23 which has been previously adjusted and locked in a substantially vertical plane tangential to the periphery of the grinding wheel. From this initial position the operator pivots the work unit in a counterclockwise direction, or toward the right as viewed in Fig. 1, while holding the pattern in continuous contact with the stop surface 23, until the work unit finally abuts the stop 51. When the work unit reaches this final position the pattern and work piece have been angularly displaced through substantially one quadrant or 90 and the work piece completely profiled with a contour corresponding to that of the pattern.

What is claimed is:

1. In a grinding machine of the character described, the combination with a frame having a bearing stock, a grinding wheel rotatably mounted in the stock and a table supported on said frame; of a work unit freely movable over the surface of said table, said work unit comprising work piece rotating means and a nonrotatable pattern; adjustable stop means comprising a bar slidably supported beneath said table on a pair of spaced parallel gibs; a vertical planar surface formed on the forward end of said bar projecting above the plane of said table; an adjusting screw supported on said table and threadedly secured in the opposite end of said bar for moving said planar surface and thereby limiting the movement of said work unit relative to the periphery of said grinding wheel; means for locking said bar; and motion limiting stop means comprising a pair of adjusting screws fixedly supported on one side of said table and an adjustable pin pivotally supported on an adjacent side of said table at substantially right angles to said adjusting screws whereby the angular displacement of the work unit when pivoted about a point on said adjustable stop means is limited to substantially 90.

2. In a grinding machine of the character described, the combination with a frame having a bearing stock, a grinding wheel rotatably mounted in said stock and a table supported on said frame; of a work unit comprising a block freely slidable on said table, spindle means for rotatably supporting a work piece in said block, adjustable plates secured at opposite ends of said block for supporting a pattern, and means supported on opposite ends of said block for adjusting said plates; and motion limiting stop means secured to said table for limiting the angular movement of said pattern and work piece relative to a point on the periphery of said grinding wheel.

3. In a grinding machine of the character described, the combination with a frame having a bearing stock, a grinding wheel rotatably mounted in said stock and a table supported on said frame; of a work unit adapted to slide freely on said table, said work unit comprising a block having bearing surfaces, meansfor adjustably supporting a pattern in said block, spindle means for rotatably supporting a work piece in said block, said spindle meanshaving a steady rest secured to said block adapted to support the shank of said work piece, and means for rotating the work piece; and stop means on said table for limiting both the longitudinal and angular movement of said pattern and work piece when moved relative to a point on the periphery of said grinding wheel. g

4. In a grinding machine of the character described, the combination with a frame having a bearing stock, a grinding wheel rotatably mounted in said stock and a table supported on said frame; of a work unit adapted to slid freely on said table, said work unit comprising a block having bearing surfaces, bearing mean including a spindle for rotatably supporting a work piece in said block, a steady-rest for said work piece comprising a plate secured to said block having a radially disposed slot adapted to support the shank of said work piec and a shank engaging jaw secured within said slot, means secured to said bearing spindle for rotating said spindle including a bushing for locking the rotatable spindle to said work piece, adjustable plates mounted on opposite ends of said block for supporting a pattern and adjusting-screws on opposite ends of said block for moving said plates and thereby adjusting said pattern relative to said work piece; stop means on said table comprising a planar vertical surface for positioning the end of the pattern tangential to the periphery of the grinding wheel; and motion limiting stop means supported on said table for limiting the angular movement of said work unit a said pattern is pivoted in point contact with said planar vertical surface.

5. In a grinding machine of the character described, the combination with a frame, a grinding wheel, and a table supported on said frame; of a work unit freely movable over said table comprising a pattern and work piece rotating means; means on said unit for adjusting sai pattern into the vertical plane of said work piece and a' gauge secured to said table for adjusting the work piece longitudinally relative to said pattern.

6. In a grinding machine of the character described, the combination with a frame having a bearing stock, a grinding wheel rotatably mounted in said stock and a table supported on said frame; of a work unit freely movable over said table comprising a pattern and work piece rotating means; means on said unit for adjusting said pattern into the vertical plane of said work piece; and a gauge comprising a standard secured to said table having a pair of gauge surfaces adapted to be contacted by said pattern and work piece respectively for adjusting the latter longitudinally relative to said pattern.

7. In a grinding machine of the character described, the combination with a frame having a bearing stock, a grinding wheel rotatably mounted in said stock and a table supported on said frame; of a work unit comprising a collet for said work piece, means for rotating said collet,

and a pattern, said unit being freely movable over said table; stop means secured to said table for limiting the movement of said work piece and pattern to a point tangential to the periphery of said grinding wheel; and means for supporting said stop means comprising gauge means adapted to be contacted by said pattern and work piece for adjusting the latter longitudinally relative to said pattern.

8. In a grinding machine of the character described, the combination with a frame having a bearing stock, a grinding wheel rotatably mounted in said stock and a table supported on said frame; of a work unit comprising a rotatable collet for supporting a work piece and a fixed pattern, said unit being freely movable over said table; adjustable stop means comprising a vertical planar surface slidably supported on said table for stopping the movement of said pattern and work piece toward said grinding wheel at a point tangential to the periphery of said grinding wheel; fixed stop means secured to two adjacent edges of the table for limiting the angular displacement of the pattern and work piece when the pattern is pivotally moved in constant contact with said planar surface; and gauge means comprising a gauge plate supported on said table adapted to be contacted by said pattern and work piece for adjusting the latter longitudinally relative to said pattern.

9. A fixture for profiling a tool comprising, in combination, a support; an adjustable stop means comprising a vertical planar surface; a work unit movable over said support comprising, means for supporting said work piece, rotating means for said work supporting means, a pattern, and means for adjusting said pattern laterally relative to said work piece; and motion limiting stops mounted on adjacent edges of said table for limiting the pivotal movement of the end of said pattern about a point on said planar surface.

10. A fixture for profiling a tool comprising, in combination, a support; a work unit comprising a sleeve for supporting the work piece, means for rotating said sleeve, and a pattern, said unit being freely movable over said support; stop means for limiting the movement of said work unit; and means for supporting said stop means comprising a gauge for adjusting the work piece relative to the'pattern.

11. A fixture for supporting a work piece in contact with the periphery of a grinding wheel comprising, in combination, a table; a work unit freely movable over said table comprising a rotatable sleeve for supporting a work piece, means for rotating said sleeve, and a fixed pattern; stop means comprising a vertical planar surface slidably mounted on said table; means for longitudinally adjusting the planar surface tangential to the periphery of a grinding wheel: motion limiting stop means for limiting the pivotal movement of the pattern when in point contact with the planar surface; and means for supporting said stop means comprising a gauge fixed to said table for adjusting the work piece relative to the pattern.

12. A fixture for profiling a tool comprising, in

combination, a table; a work unit movable over said table, said unit comprising a block adapted to slide freely on said table said block having bearing surfaces, means including a spindle for rotatably supporting a work piece in said block a steady-rest for said work piece comprising a plate secured to one of said bearing surfaces having a radially disposed slot adapted to support the shank of said work piece, a shank engaging Jaw secured within said slot, means secured to said bearin spindle for rotating said spindle including a collet for locking the rotatable spindle to said work piece; adjustable plates mounted on opposite ends of said block for supporting a pattern and adjusting screws opposite the ends of said plates for moving said plates and thereby adjusting said pattern laterally relative to said work piece; stop means on said table comprising a longitudinally adjustable planar surface for stopping the longitudinal movement of said pattern in a plane tangential to th periphery of a grinding wheel; and adjusting screws fixed to said table for limiting the angular movement of said pattern and work piece when the end of said pattern is pivoted about a point on said adjustable planar surface.

7 JOHN W. EKSTEDI'.

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