US2606403A - Device for producing noncircular profiles - Google Patents

Device for producing noncircular profiles Download PDF

Info

Publication number
US2606403A
US2606403A US91351A US9135149A US2606403A US 2606403 A US2606403 A US 2606403A US 91351 A US91351 A US 91351A US 9135149 A US9135149 A US 9135149A US 2606403 A US2606403 A US 2606403A
Authority
US
United States
Prior art keywords
tool
support
grinding
rotatable
profiles
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US91351A
Other languages
English (en)
Inventor
Musyl Robert
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
MANUF DE MACHINES DE HAUTE RHI
MANUFACTURE DE MACHINES DE HAUTE RHIN
Original Assignee
MANUF DE MACHINES DE HAUTE RHI
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by MANUF DE MACHINES DE HAUTE RHI filed Critical MANUF DE MACHINES DE HAUTE RHI
Application granted granted Critical
Publication of US2606403A publication Critical patent/US2606403A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B19/00—Single-purpose machines or devices for particular grinding operations not covered by any other main group
    • B24B19/08—Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding non-circular cross-sections, e.g. shafts of elliptical or polygonal cross-section
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q27/00—Geometrical mechanisms for the production of work of particular shapes, not fully provided for in another subclass
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q27/00—Geometrical mechanisms for the production of work of particular shapes, not fully provided for in another subclass
    • B23Q27/006—Geometrical mechanisms for the production of work of particular shapes, not fully provided for in another subclass by rolling without slippage two bodies of particular shape relative to each other
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/51—Plural diverse manufacturing apparatus including means for metal shaping or assembling
    • Y10T29/5104—Type of machine
    • Y10T29/5109—Lathe
    • Y10T29/511—Grinding attachment
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T409/00—Gear cutting, milling, or planing
    • Y10T409/30—Milling
    • Y10T409/30084—Milling with regulation of operation by templet, card, or other replaceable information supply
    • Y10T409/302968—Milling with regulation of operation by templet, card, or other replaceable information supply including means for operation without manual intervention
    • Y10T409/303248—Milling with regulation of operation by templet, card, or other replaceable information supply including means for operation without manual intervention with provision for circumferential relative movement of cutter and work

Definitions

  • ROBERT MUSVL A T TORN V Aug. 12, 1952 R. MUSYL 2,606,403
  • the presentinvention relates to a device and/or machine-tool capable of precisely producing noncircular cyclic innerand outer-profiles, whereby non- -circular cyclic profiles are, understood in this description to cover mainlyeccentrics, elliptical two-cornered profiles, as well as three-cornered, four-cornered, etc. profiles. These profiles serve chiefly the purpose of Connecting shafts and hubs.
  • the task which the invention intends to solve is to create a machine on which both the preliminary work of turning and milling, and the finishing work of outer-. or inner-grinding can be carried out.
  • a further disadvantage of the hitherto devices consists in that the whole grinding block participates in the oscillating movement of the tool in respect to the workpiece," necessary for obtaining the non-circular profile. Thereby forces of inertia are generated which reduce the precision of the profile. Besides the finish is impaired by the shocks caused by the driving motor, which participates in the oscillation of the grinding block, being but uncompletely balanced.
  • thermore there is the danger of the'finished surfaces showing a dilferent degree of hardness in case of a surface-hardening process being carried out between the preliminary work and the finishing.
  • the device according. to'jthe present invention not only permits to eliminate these drawbacks, but additionally renders possible the production of non-circular profiles'ot any number of corners (multi-corneredprofiles).
  • the ch e feature of the invention are put forth:
  • the oscillating motion is not imparted to the entire tool-block, but solely tofthetool and to the tool-holder.
  • the cyclic non-circular profile is, in a manner already known, so shaped that it can be producedfwith the workpiece rotating at a uniform speed.
  • the tool-block does not participate in' the oscillating motions of the tool, the driving motor too remains stationary, so thatthe quality of the finish is not impaired even if the dynamical balance of the motor is not quite irreproachable.
  • FIGs. 1-12 an embodiment of the invention is represented by way of example.
  • the Figs. 1-3 show various positions of the workpiece in respect to the tool.
  • Fig. 4 is a diagram representing a gear for driving a grinding Wheel for innerand outer-grinding operations.
  • Fig. 5 shows the continuously adjustable control eccentric.
  • Figs. 6 and 7 are a longitudinal and a transversal section through the drive of the milling device.
  • Fig. 8 is a frontal view of the whole machinetool.
  • Fig. 9 is a lateral view thereto.
  • Fig. 10 is aview of the machine frame above with the grinding spindle for inside work being located in the operation.
  • Figs. 11-12 are a plan and an end view of the machine, when used for milling.
  • the Figs. 1-3 represent by way of example a non-circular two-cornered workpiece, whereby the method of grinding the outer profile is illustrated in various working positions.
  • the motion of the tool is arranged in such a manner that the operation is always carried out in the perpendicular to the curve, which means that the shape of the profile generated is independent of the diameter of the tool.
  • the workpiece I executes one revolution the tool 2 is compelled, on the strength of the geometrical laws, to travel n-times (for an n-cornered workpiece) through the generating curve 3.
  • the cinematics of these motions are known.
  • the perpendicular to the curve 11. is displaced upwards by the length of the great axis of the generating curve 3.
  • the center of the grinding wheel coincides with the left-hand apex of the generating curve, and in Fig. 3 with the right-hand apex.
  • the shape of the generating curve results, with mathematical precision, from the shape of the non-circular profile which is to be produced. If said shape is selected so that, with profiles having an odd number of corners, the same measuring distance is produced in any position, i. e. that a body of equal thickness is attained-which is highly advantageous in view of the possibility of employing usual calibres (grooves) in outer profileson basis of the mathematical laws the generating curve is formed to be an ellipse, the ratio of the axes of which corresponds to the number of corners. This relation is the basis for the design of the controlling gear according to Fig. 4.
  • control eccentric is designated by numeral 4, the control movement being derived from said eccentric.
  • this eccentric is continuously adjustable from the eccentricity zero (circular working) up to the maximum eccentricity.
  • the tools used are, on the left-hand side, an outer-grinding wheel 5 for working the outer profile 6, and on the righthand side an inner-grinding wheel 1 for working the inner profile 8.
  • the motion of the tool required for realizing the profile shape is composed of two components, the one coinciding with the feeding direction of the tool (i. e. horizontal according to Fig. 4), and the other to the direction perpendicular to the feeding direction (1. e. vertical according to Fig. 4).
  • the component acting in the feeding direction is, by the control eccentric and the tappets 9 and 9a, directly transmitted on to the tool support, whereas the component acting in the perpendicular direction thereto is transmitted indirectly by way of the tappets l0 and Illa. located one behind the other in the drawing, the double-armed levers l l and I la, and the tappets l2 and I2a. All tappets are guided in the tool-block.
  • the ratio of transmission of the levers l l and I la is adjustable according to the number of corners of the profile to be produced by means of stuck-in bolts I3 and I3a, located between the levers II and Ila, and the lever supports [4 and Ma. The ratio of transmission amounts to 1:11., whereby n is the number of corners of the profile to be produced.
  • the suspension of the grinding wheel support is taken care of by the oscillating levers l5 and 15a, supported in the tool-block, as well as by the links I6 and Hill.
  • This mode of suspension assures a guidage parallel to the axis without, however, reducing the mobility in the direction perpendicular to the grinding spindle axis, the traction springs I1 and lla warranting a positive operative connection of the tool support with the control eccentric 4.
  • the drive of the grinding wheels 5 and I of said embodiment. is derived from the motor [8, fixed to the tool-block and consequently not partaking in the oscillation, two V-shaped belt drives l9 and 19a, as well as 20 and 20a taking care of the transmission of the energy.
  • the mean belt pulley support is lodged in the guide so that the belt length is not altered by the control motions of the tool.
  • Fig. 5 shows the adjustable control eccentric (4 in Fig. 4).
  • a second eccentric 22 having the same eccentricity, is rotatably arranged on the eccentric 2
  • the amplitude of the efficient eccentricity can be adjusted continuously from zero to 2e. This is effected by operating the hand wheel 23 which acts on the gear wheels 24, 25, 2B and the inner toothing 21.
  • the position of the two eccentrics is fixed in regard to each other by means of the clamping sleeve 28 and the clamping screw 29.
  • the movement of the eccentric is transmitted to the tappets 9, 9a, l0 and [0a (Fig. 4).
  • the drive of the eccentric shaft supported in the tool-block is effected by the control motor 32, acting by way of the gear wheels 33.
  • the control motor 32 acting by way of the gear wheels 33.
  • Figs. 6 and 7 showthe support and the drive for a milling device preferably intended for the preliminary workon outer profiles which this case infinite, no control motion is necessary in the perpendicular to the feeding direction which feature is of great importance for the precision of the tool guidage in view of the-relatively high cutting pressure occuring in milling.
  • the tool only carries out: an oscillating motion in the feeding direction which is either derived directly from the tappet 9a. (Fig. 4) or as represented in the embodiment under consideration from a bushing 34, rotatably arranged on the bearing sleeve of the inner grinding spindle I.
  • the hollow shaft 36 rotatably journalled in an additional casing 35, rigidly connected to the tool-block, is actuated by the motor l8 (Fig. 4) by way of a belt drive (not shown) as well as by a worm 31 and a wormgear wheel 38.
  • the milling spindle 39 is longitudinally shiftable, but is rotatably coupled with said shaft.
  • the milling spindle 39 shows a conical bore for 'the shank of the milling cutter 42, whilst at the other end an arrangement is provided for the bearing of a rotatable mushroom-shaped part 40 which rests on the bushing 34 of the inner grinding device 1 or directly on the tappet 9a (Fig. 4).
  • assures a permanent and operative connection between the milling cutter 42 and the element from which the oscillating motion is derived.
  • the Figs. 8 and 9 are a frontal view and an end view of the machine-tool as a whole.
  • Numeral 43 designates the machine base on which the carriage 44, supporting the headstock 45 and the tailstock 46, is so arranged as to be shiftable in the longitudinal direction.
  • the tool-block 41, located behind, is shiftable in the feeding direc tion of the tools, besides being rotatable about a vertical axis 48 in such a manner that the various tools such as the outer-grinding wheel 5 in Fig. 8, the outer-grinding wheel 5 and the milling cutter 42 in Fig. 9 can be moved into their operating position.
  • Fig. is an overall plan of the machine-tool, whereby the tool-block 41 is turned through 180 in respect to the positions shown in the Figs. 8 and 9, whereas the inner-grinding wheel I occupies its working position.
  • the Figs. 11 and 12 also show the whole machine seen from above, and by way of an end view, but in its case with the milling head 42 in its operating position.
  • the numeral 43 refers to the machine base, 44 to the carriage, 45 and 46 to the headstock and the tailstock, and 4'! to the tool-block.
  • the outergrinding wheel 5 occupies a position outside of the tool-block turned away from the workpiece.
  • a machine tool comprising a rotatable work supporaa tool, arotatable support for-said tool mounted to move parallel to its axis of'rotation, a
  • single rotating cam means having a continuous single surface, and-two cam follower means engaging different portions of said surface and being guided for movementindifferent directions, said follower means'eng'ag-ing said tool support for moving it parallel to] its axis of rotation in a direction resulting from the combination of the movements of said follower-means.
  • one of said cam. follower means being formed by a tappet' rod having one end engaging said cam and another end engaging said tool support, and the other follower means being composed of two tappet rods and atwo arm lever, one end of one tappet rod engaging said cam and the other end engaging one arm of said lever, one end of the other tappet rod. engaging the other arm of said lever and its other end engaging said tool holder.
  • a machine tool as-set forth in claim 2 comprising resilient means pressing said tool holder to the two tappet rods by which i-tis engaged.
  • a machine tool asset-forth inclaim 2 said lever having a displaceable fulcrum for chang ing its leverage. 1 u H I 6.
  • a machine tool having a rotatable work support, a tool, a rotatable'support for said tool mounted to move-parallel to its axis of rotation, an eccentric, and two motion transmitting. means actuated by said eccentric andibeingguided to move in different directions and individually engaging said tool support for transmitting'the movement of said eccentric thereto and moving it parallel to its axis of rotation in a direction resulting from the combination of the movements of said two transmitting means.
  • a machine tool as set forth in claim 7, comprising means for rotating said eccentrics relative to one another for changing their composite eccentricity.
  • r I V v 11 A machine tool for shaping the surface of a workpiece comprising, in combination, a rotatable work support, a tool, a rotatable support for said tool movable parallel to its axis of rotation, a rotatable cam means, and two motion transmitting means actuated by said cam means and guided to move in different directions and individually movably connected with said tool support for transmitting the movement of said cam means thereto and moving it parallel to its axis of rotation in a direction resulting from the combination of the movements of the two transmitting means.
  • one of said transmitting means comprising variable transmitting means for changing the extent of motion imparted to the tool support by the last mentioned transmitting means relative to the extent to which it is actuated by said cam means.
  • a machine tool for shaping the surface of a work piece comprising, in combination; a rotatablework support, a tool, va rotatable support for said tool movable parallel to its axis of rotation, a rotatable cam means, two motion transmitting means actuated by said-cam means and guided to move in different directions and individually movably connected with said tool support for transmitting the movement of said cam means theretoand moving it parallel to its axis of rotation in a direction resulting from the combination of themovements of the two transmitting means, a stationary motor, a pulley swingably linked to said motor, means swingably suspending said work support from said pulley, and flexible means connecting said motor with said pulley and said pulley with said work support for rotating the latter by said motor.
  • a machine tool for shaping work pieces internally and externally comprising, in combination, a rotatable work support, two. tools, a rotatable support for each tool, said supports being individually movable parallel to their rotation axes, a rotatable cam means, a motion transmitting mechanism for each tool support, each mechanism comprising two motion transmitting means actuated by said cam means and guided to move in different directions and individually movably connected with one of said tool supports for transmitting the movement of said cam means thereto and moving it parallel to its axis of rotation in a direction resulting from the combination of the movements of the two transmitting means.
  • a machine tool as defined in claim 13, comprising a machine bed supporting said work support and a turret rotatably supported by said bed and supporting said tool supports, said cam means, and said motion transmitting mechanisms.
  • a machine for preliminarily milling and finally grinding the surface of a work piece comprising, in combination, a rotatable work support, a grinding tool, a rotatable support for said grinding tool movable parallel to its axis of rotation, a rotatable cam means, two motion transmitting means actuated by said cam means and guided to move in different directions and individually movably connected with said tool support for transmitting the movement of said cam means thereto and moving it parallel to its axis of rotation in a direction resulting from the combination of the movements of the two transmitting means, a milling tool, and a rotatable and axially movable support'for said milling tool engaged by said grinding tool support for axial movement toward and from the work in accordance with the lateral compor Number nent of the movement of the grinding tool support.
  • a machine for preliminarily milling and finally grinding the surface of a work piece comprising, in combination, a rotatable work support, a grinding tool, a rotatable support therefor movable parallel to its axis of, rotation, a rotatable cam means, two motion transmitting means actuated by said cam means and guided to move in different directions and individually movably connected with said tool support for transmitting the movement of said cam means thereto and moving it parallel to its axis of rotation in a direction resulting from the combination of the movements of the two transmitting means, a milling tool, a rotatable and axially movable support therefor, and motion transmitting means actuated by said cam means and movably connected with said milling tool support for moving it in axial direction.
  • a machine tool for shaping the surface of a work piece comprising, in combination, a rotatable work support, a tool, a rotatable support for said tool movable parallel to its axis of rotation, a rotatable cam means, two motion transmitting means actuated by said cam means and guided to move in diiferent directions and individually movably connected with said tool support for transmitting the movement of said cam means thereto and moving it parallel to its axis of rotation in a direction resulting from the combination of the movements of the two transmitting means, a normally stationary turret, a motor fixed to said turret to rotate said cam means, a second motor fixed to said turret, and flexible means connecting said second motor and said tool support for rotating it.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Geometry (AREA)
  • Grinding And Polishing Of Tertiary Curved Surfaces And Surfaces With Complex Shapes (AREA)
US91351A 1948-05-08 1949-05-04 Device for producing noncircular profiles Expired - Lifetime US2606403A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
AT279706X 1948-05-08

Publications (1)

Publication Number Publication Date
US2606403A true US2606403A (en) 1952-08-12

Family

ID=3670711

Family Applications (1)

Application Number Title Priority Date Filing Date
US91351A Expired - Lifetime US2606403A (en) 1948-05-08 1949-05-04 Device for producing noncircular profiles

Country Status (2)

Country Link
US (1) US2606403A (xx)
NL (2) NL146202B (xx)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2870578A (en) * 1957-03-18 1959-01-27 Nsu Werke Ag Mechanism for machining trochoidal rotors and counter-rotors
US3693297A (en) * 1970-03-24 1972-09-26 Bryant Grinder Corp Apparatus and method for grinding irregular surfaces of revolution
US4617762A (en) * 1983-07-18 1986-10-21 Carl Hoglund Cam controlled machine for forming non-standard surfaces

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US612239A (en) * 1898-10-11 Machine for dressing metals or other materials
GB417612A (en) * 1932-04-22 1934-10-09 Asea Ab Improvements in and relating to the grinding of curved surfaces
US2189931A (en) * 1939-01-27 1940-02-13 Norton Co Grinding machine
US2210273A (en) * 1938-09-23 1940-08-06 Gleason Works Method of and apparatus for relieving cutters
US2290051A (en) * 1939-10-05 1942-07-14 Corning Glass Works Contour grinding apparatus
US2350234A (en) * 1940-11-09 1944-05-30 Super Tool Company Grinding machine
US2378127A (en) * 1943-07-01 1945-06-12 Bryant Grinder Corp Grinding machine
US2415062A (en) * 1946-01-24 1947-01-28 Norton Co Cam grinding apparatus
US2452989A (en) * 1943-12-18 1948-11-02 Nat Acme Co Cam grinding machine

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US612239A (en) * 1898-10-11 Machine for dressing metals or other materials
GB417612A (en) * 1932-04-22 1934-10-09 Asea Ab Improvements in and relating to the grinding of curved surfaces
US2210273A (en) * 1938-09-23 1940-08-06 Gleason Works Method of and apparatus for relieving cutters
US2189931A (en) * 1939-01-27 1940-02-13 Norton Co Grinding machine
US2290051A (en) * 1939-10-05 1942-07-14 Corning Glass Works Contour grinding apparatus
US2350234A (en) * 1940-11-09 1944-05-30 Super Tool Company Grinding machine
US2378127A (en) * 1943-07-01 1945-06-12 Bryant Grinder Corp Grinding machine
US2452989A (en) * 1943-12-18 1948-11-02 Nat Acme Co Cam grinding machine
US2415062A (en) * 1946-01-24 1947-01-28 Norton Co Cam grinding apparatus

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2870578A (en) * 1957-03-18 1959-01-27 Nsu Werke Ag Mechanism for machining trochoidal rotors and counter-rotors
US3693297A (en) * 1970-03-24 1972-09-26 Bryant Grinder Corp Apparatus and method for grinding irregular surfaces of revolution
US4617762A (en) * 1983-07-18 1986-10-21 Carl Hoglund Cam controlled machine for forming non-standard surfaces

Also Published As

Publication number Publication date
NL146202B (nl)
NL85860C (xx)

Similar Documents

Publication Publication Date Title
US3905156A (en) Thread grinding machine with a device for the relief grinding of the threads on tap drills and internal thread formers
US4154145A (en) Bore slotting machine
US3653243A (en) Device for forming closing heads at rivets
US2909010A (en) Process of and apparatus for forming manifold symmetrical non-circular profiles on workpieces
US2606403A (en) Device for producing noncircular profiles
US3751996A (en) Device for transmitting adjustable translatory movements in two axis-directions
US3659496A (en) Machine for shaping gears
US2267250A (en) Production of cross-section profiles bounded by cycloidal curves
US2125304A (en) Cutter relieving means for shaping machines
US2784649A (en) Machine tool for the production of blades of centrifugal machines
US2801505A (en) Cam grinding machine
US2739501A (en) Lathe
US3142940A (en) Machine for lapping gears
US3621618A (en) Apparatus for producing and machining cyclic non-round profiles
US1322352A (en) Automatic lathe
US4638599A (en) Gear grinding machine for radial or helical spur gears
US3516206A (en) Continuously-adjustable variable mechanisms and machine tools incorporating same
US2376110A (en) Machine for machining screw gears
US1958507A (en) Milling machinery
US3736113A (en) Spiral grinding relieving machine with tandem planetary differential drive
US3018699A (en) Device for the realization of cams, especially for controlling automatic tools and the like
US1662109A (en) High-speed-gear-generating machine
US2619878A (en) Apparatus for machining inclined ball seats
US2696066A (en) Grinding machine
US2414283A (en) Gear cutting machine for spur and screw gears