US3080685A - Grinding machine - Google Patents

Description

March l2, 1963 w. T. HocKlNG GRINDING MACHINE Filed Nov. 25. 1960 2 Sheets-Sheet 1 A TTOENE Y March 12, 1963 w. T. HocKlNG 3,080,685

GRINDING MACHINE Filed Nov. 25, 1960 2 Sheel'.sSheeiI 2 INVENTOR. WIA/FRED T Hocfgnve ATTORNEY nite Patented Mar. 12, 1963 3,080,6ss GRlNDlNG MACHINE Winfrcd T. Hocking, Northboro, Mass., assignor to Norton Company, Worcester, Mass., a corporation of Massachusetts Filed Nov. 25, 1960, Ser. No. 71,788 S Claims. (Cl. 51-,-92)

The invention relates to grinding machines and more particularly to a cutter and tool grinding machine.

In grinding machines of this type either the grinding wheel slide is manually traversed toward a workpiece or Ithe work support is vmanually traversed toward the grinding wheel on a slideway consisting of a pair of atways or atlat and a V way. The feed mechanism for this pur-r pose,l commonly a nut `and screw feed mechanism, is usually located to one side of the grinding -wheel slide, above orbelow the horizontal plane of the slideways, and extending through the machine so l,that it is operable from either the front or the back of the machine. An offset feed mechanism of this type has an inherent tendency to bind up and is not smooth in operation so that the slide tends to cock on its slideway due to 'the moment arm resulting from the offset location of the feed mechanism and due to friction introduced by the weight of the slide.

lt is `one object of this invention to provide a rigid simplied and economically constructed slideway, wheel slide and wheel slide traversing mechanism.

Another object of this invention is to provide a well balanced wheel slide whose center of gravity -lies between ya pair of slideways supporting it.

Still another object of this invention is to provide tubular slideways that pass through and engage ma-ting internal surfaces in a wheel slide.

Yet another object of this invention is to provide a slideway of such a cross section that it wi-ll only allow movement of the wheel slide in a direction parallel to the slideway, thereby eliminating distortion of the grinding machine.

v A further object of this invention is to provide a simplified feeding mechanism that operates smoothly and easily Vwithout binding.

An additional object of the invention is Ito provide a traversing mechanism that is enclosed within one of the slideways. Other objects and advantages of the invention will be lapparent by reference to the following specification and the accompanying drawings illustrating one embodiment of the invention in which:

FIG. l is Ia plan view, partly in section, of a cutter and tool grinding machine showing the grinding wheel slide and its feeding mechanism,

FIG. 2 is a partial sectional View taken approximately on line 2-2 of FIG. l, showing the construction of the wheel slide, and its supporting slideways and feeding mechanism, and

FIG. 3 is a sectional view [taken approximately on line 3-3 of FIG. 1, through one of slideways showing a por tion of the feed mechanism.

Referring to the drawings, the machine comprises a base upon which a table 12 is slidably mounted by means of the customary ways, not shown. The table 12 supports a swivel table 14 upon which is adjustably mounted a pair of work supports 16 andlS, between which may be placed and retained la workpiece to be ground. A plurality of manually operable cranks or knobs 2t) are part of a table traversing mechanism not a part of the instan-t invention and well known in -th'e art. Accordingly, details of thetable traversing mechanism are not shown. Rotation of the knobs 20 in one direction or the other will correspondingly traverse the table The base 10 is provided with an elongated cavity 10a between its sides .10b and 10c land rear and front portions 10d and 10e within which is traversed a grinding wheel slide 22 supported y'by a pairof . tubular slideways 24 and 26 fixed against movement relative to the base 10' and extending from within front portion 10e, spanning the cavity 10a, and projecting into the rear portion 10d. The wheel slide 22 consists of frame 22a extending down into the cavity 10a land has integral therewith a transversely disposed housing 22b at the top and Ia pair of horizontally spaced parallel slideway housings 22e kand 22d reinforced by a pair of gussets 22e and 221' and a cross member 22g integral with the wheel slide 2 2.

A vertically mounted feed screw 28 located at the mid point between the slideway housings 22e and 22d is rotatably mounted within the frame portion 22a of the wheel slide 22 but fixed against axial movement relative thereto. The feed -screw is journalled at its upper end in Ia bearing 3f) and at its lower end in a bearing 32, bearings 30 and 32 in t-urn being `secured to the frame portion 22a. At its upper end is fixed a helical gear 34, meshing with a helical gear 36 fixed to a rotatable shaft 38 journalled within bearings not shown in the transversely disposed housing 22b and to which is fixed, at its opposite ends, a pair of manually rotatable handwheels 40 and 40a. Thus, rotation of shaft 38 by either of the handwheels 40` and 40a produces rotation of the feed screw 28. Also enclosed within 'and supported on the frame por-tion 22 is a vertical dovetail slideway 22h engaged by a vertical slide 42 with coacting mating surfaces The ventical slide 42 is supported and positioned relative to the dovetail slideway 22h by a nut 44 fixedly secu-red to the slide 42 and engaged by the vertical rotatable feed screw 28.

VA wheelhead supported by and adjustably mounted at the upper end of the vertical slide 42 comprises a rotatably adjustable base 52 secured to the vertical slide 42, an adjustable wheel spindle housing 54 tiltable about a horizontal pivot 56 and locked by a screw 58 in the desired position against a pair of flat upright surfaces 52a of the adjustable base 52, and a wheel drive motor 66 mounted on an adjustable motor base 62 fixed to the wheel spindle housing 54 and swivelable or tiltable therewith. The motor 60 has a variable V groove pulley 64 fixed to its shaft and connected by a belt 66 to another variable V-groove pulley 68 xedly mounted on a spindle 7i? for rotating the grinding wheels or cutting tools 72 and 72a. It can be readily seen that when it is desired, the wheelhead 50 and the grinding wheels can be raised or lowered in elevation by manually rotating either of the hand wheels 40 or 40a; can be manually rotated 360 in a horizontal plane and locked in any position relative to the vertical slide 42; and can be angularly swivelle'd or tilted in a vertical plane in either direction from a horizontal position parallel to the table 14.

As above described, the wheel slide 22 consists of a pair of elongated lslideway housings 22C and22d, substantially equally spaced from the axis of the feed screw 28, and of the vertical slide 42 which is located at the center of the frame 22a of the wheel slide 22 at approximately its center of gravity. This well balanced construction 'distributes the weight equally between the slideways 24 and 26, resulting in a freely moving slide.

Within each of the slideway housings 22e and 22d are spaced bearings 23 which engage the ' slideways 24 and 26 and may be lubricated in any suitable manner such as by filling the space between the respective bearings 23 in each of the slideway housings with a lubricating medium, thereby continuously lubricating the slideways.'

As illustrated in the drawings, the slideways 24 and 26 Aare preferably round tubular members engaging the entire internal surfaces of the large bearings :23 fixed within the slideway housings 22e and 22d. Thus, unlike at and V ways, these fully encircled slideways positively conspaanse strain the wheel slide slidable thereon at all times against any displacement relative thereto including angular displacement, except relative displacement in either direction along a line parallel to the longitudinal axes of the slideways 24 and 26.

An enclosed feeding mechanism is provided for traversing the grinding wheel slide 22 on the slideways 24 and Z6, relative to the work supports 16 and i8. It comprises a rotatable feed screw shaft 74 journalled at its opposite ends in anti-friction bearings 76 and '73 and also constrained thereby against axial movement. The bearings 76 and 78 are in turn secured in fixed positions within the slideway 26 which is fixedly mounted upon the base lil as described above. A pair of rotatable hand wheels Si) and 80a are fixed to each end of the feed screw shaft 74 so that it may be rotated from either the front or back of the machine.

Located within the slideway 26 and engaging the threaded portion of the feed screw shaft 74 is a full nut 82 ixedly mounted to the underside of the slideway housing 22C of the grinding wheel slide 22. The nut 82. has for its entire length a narrow section 82a integrally inter-connecting the circular nut portion S2b and a base portion 82e, attached by screws 84 to a plate S6 in turn fixed to the slideway housing 22C by screws S3.

As shown in the drawing, a plurality of openings 90 and 92 are provided through the bottom of the slideway housing 22C and the slideway 26 for inserting the nut 82 into a central position within the hollow slideway 26 so that the nut 82 is properly disposed to be threadably engaged by the feed screw shaft 74. Putting the necessary openings in the bottom of the slideway 26 provides an enclosure for the feed mechanism protecting it from dirt and grit, maintaining a smooth and easily operable mechanism. In order that the nut 82 may be traversed a sutilcient distance, an elongated slot 94 is provided in the slideway 26 through which the narrow portion 82a of the nut 82 passes with sufficient clearance for unrestrained relative movement.

Noting the symmetrical disposition of the slideways 24 and 26 relative to the wheel slide 22 and the favorable vertical distribution of weight of the wheel slide 22 with approximately equal portions disposed above and below the horizontal plane in which slideways 24 and 26 lie, it should be apparent that wheel slide 22 is arranged to move easily in either direction along slideways 24 and 26 without any inherent tendency to shift angularly about a horizontal axis. Moreover, the location of the feed mechanism coaxially with one of the slideways avoids the introduction of the vertical moment arm for the thrust applied -by the feed mechanism which is characteristic of vertically oifset feed mechanisms. Hence, thrust loads applied through the feed mechanism do not tend to tilt the wheel slide 22 about a horizontal axis. Finally, the relatively wide spacing of bearings 23 within the respective elongated slideway housings 22e and 22d and the closely intertitting engagement of the bearings 23 with the slideways 24 and 26 they enclose on all sides effectively constrain the wheel slide 22 against angular displacement about either a horizontal axis or a vertical axis. Thus, the instant invention provides a compact configuration of relatively simple construction for a combination of elements comprising slideways, a wheel slide, and a wheel slide feed mechanism so disposed and interconnected as to be highly resistant to distortion in use of this combination of elements either by internal distortion of any element or by undesirable relative displacement of coacting elements.

From the foregoing it can be seen that an improved substantially enclosed grinding wheel feed mechanism has been provided in combination with a well balanced grinding wheel slide supported on improved slideways having increased bearing surfaces, thereby eliminating binding and distortion therein and assuring smooth vibrationless movement of the grinding wheel.

Having thus illustrated and described the preferred embodiment of the invention, it will be understood that many modifications may be made of the invention within the scope of the following claims.

What is claimed is:

l. A cutter and tool grinding machine comprising a base, an elongated table longitudinally movable on said base, work supporting means mounted on said table, a pair of transversely disposed horizontal spaced parallel hollow slideways fixed to said base and disposed transversely of said elongated table, a transversely movable wheel slide slidably supported by said parallel slideways and otherwise continuously fully constrained against any movement relative to said slideways, a wheel slide traversing mechanism asymmetrically disposed along one side of said wheel slide and substantially enclosed within one of said parallel slideways, a vertical slideway on said Wheel slide symmetrically disposed midway between said parallel slideways, a vertical slide movable on said vertical slideway, a rotatable and tiltable wheel head including at least one grinding wheel mounted on said vertcial slide, and means to move and position said vertical slide in cluding the wheel head mounted thereon vertically relative to said work supporting means.

2. A machine tool comprising a base, a pair of transversely disposed spaced parallel slideways, at least one of which is hollow, both mounted fixedly on said base, a transversely movable wheel slide substantially symmetrical about a vertical plane midway between and parallel to said slideways slidably supported by said slideways and continuously fully constrained against any other movement relative to said slideways, and a wheel slide traversing mechanism asymmetrically disposed along one side of said wheel slide and substantially enclosed within one of said slideways.

3. A grinding machine comprising a base, a transversely movable wheel slide, a pair of horizontally disposed hollow slideways fixed to said base, said slideways slidably engaging and otherwise continuously fully constraining internal bearing surfaces of said transversely movable wheel slide supported by said slideways, and a wheel slide .traversing mechanism manually operable from either end thereof and substantially enclosed within one of said slideways.

4. A machine tool comprising a pair of horizontally disposed parallel tixedly mounted tubular supporting slideways passing through and slidably engaged by rst and second pairs of fully encircling bearing surfaces of a machine tool slide respectively spaced longitudinally of the respective slideways, a single externally rotatable feed screw threaded through a nut fixed to and movable with the machine tool slide and substantially enclosed within one of the supporting slideways, said supporting slideway enclosing said feed screw having an elongated clearance opening along its underside through which the nut attached to said machine tool slide extends and is traversed.

5. A machine tool comprising a base, a pair of horizontal parallel slideways, one of which is hollow, supported by said base, a movable slide having internal bear ing surfaces in continuous sliding engagement with spaced portions of said parallel slideways so that said slide is continuously fully constrained against any other movement relative to said slideways, and externally rotatable feed screw passing through and substantially enclosed by said hollow slideway, and a nut threaded on said feed screw and fixed to and movable with said slide in response to rotation of said feed screw.

6. A machine tool including horizontally disposed parallel slideways at least one of which has a central opening through its entire length, said parallel slideways having external bearing surfaces about substantially their entire exposed perimeter and length, a movable slide supported by said parallel slideways having internal bearing surfaces including mutually opposed portions c0ntinuously disposed in bearing engagement with complementary mutually opposed portions of the external bearing surfaces of said parallel slideways, a feed screw passing through the opening through one of the parallel slideways, said feed screw being xed against aXial movement in said slideway and rotatable from either end thereof, a nut engaging `said feed screw fixed to and movable with said slide, and an elongated clearance opening through the underside of the slideway having a central opening therethrough for inserting and traversing said nut.

7. A machine tool comprising a base, a pair of transversely disposed horizontall spaced tubular parallel slideways xed to said base, a transversely movable wheel slide with its center of gravity substantially midway between a pair of openings therethrough having internal bearing surfaces fully encircling and continuously maintained in sliding engagement with but otherwise fully constrained relative to the external surfaces of said tubular slideways so that said wheel slide is continuously limited solely to sliding movement lengthwise of said slideways, and a wheel slide traversing mechanism substantially enclosed within one of said parallel slideways.

8. A grinding machine comprising a base, a pair of transversely disposed spaced hollow circular parallel slideways disposed with their axes in a common horizontal plane and xed to said base, a transversely movable wheel slide having its center of gravity between a pair of holes therethrough with bearing surfaces fully encircling and continuously in full bearing engagement with said parallel slideways, a wheel slide traversing mechanism including a nut connected to said wheel slide and an externally rotatable screw disposed concentrically within and fully protected from falling grit by one of said parallel slideways.

References Cited in the le of this patent UNITED STATES PATENTS 877,170 Carlson Ian. 2l, 1908 921,343 Bastian et al May 11, 1909 1,172,183 Wardwell Feb. 15, 1916 2,203,488 Carlson June 4, 1940 2,239,639 Amidon Apr. 22, 1941 2,486,108 Brunel Oct. 25, 1949 2,905,211 Weinstein Sept. 22, 1959

Claims (1)

1. 8. A GRINDING MACHINE COMPRISING A BASE, A PAIR OF TRANSVERSELY DISPOSED SPACED HOLLOW CIRCULAR PARALLEL SLIDEWAYS DISPOSED WITH THEIR AXES IN A COMMON HORIZONTAL PLANE AND FIXED TO SAID BASE, A TRANSVERSELY MOVABLE WHEEL SLIDE HAVING ITS CENTER OF GRAVITY BETWEEN A PAIR OF HOLES THERETHROUGH WITH BEARING SURFACES FULLY ENCIRCLING AND CONTINUOUSLY IN FULL BEARING ENGAGEMENT WITH SAID PARALLEL SLIDEWAYS, A WHEEL SLIDE TRAVERSING MECHANISM INCLUDING A NUT CONNECTED TO SAID WHEEL SLIDE AND AN EXTERNALLY ROTATABLE SCREW DISPOSED CONCENTRICALLY WITHIN AND FULLY PROTECTED FROM FALLING GRIT BY ONE OF SAID PARALLEL SLIDEWAYS.

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