US2863263A

US2863263A - Work support

Info

Publication number: US2863263A
Application number: US634452A
Authority: US
Inventors: Fred T Perkes; Joseph M Vernon
Original assignee: Thompson Products Inc
Current assignee: Northrop Grumman Space and Mission Systems Corp
Priority date: 1957-01-16
Filing date: 1957-01-16
Publication date: 1958-12-09
Anticipated expiration: 1975-12-09

Description

Dec. 9, 1958 F. T. PERKES ET AL 2,863,263

woRK SUPPORT Filed Jan. 1e, 1957 m 4% wfg United States Patent O WRK SUPPORT Fred T. Perkes, Willoughby, and Joseph M. Vernon, Euclid, Ohio, assignors to Thompson Products, Inc., Cleveland, Ohio, a corporation of Ohio Application January 16, 1957, Serial No. 634,452

8 Claims. (Cl. 51-238) This invention relates to an improved work support assembly of the type used in centerless grinding operations, and more particularly relates to an improved work support assembly that utilizes an axially journaled roll at the point of contact between a workpiece and the work support, such that the relative rotative movement between the workpiece and the work support will be accommodated by the roll, and displaced work and abrasive fragments will be harmlessly directed away from the area of contact between the roll and workpiece.

In the past, conventional work supports or rests were either of the stationary bearing plate or roll type, the latter type having the rolls supported in bearings at their end extremities or at various points along their axial length. ln each case, the work supports were formed from relatively soft materials and in the stationary bearing plate type support, a relatively unmovable point of contact was presented between the support, each of these factors contributing to the wear of the support.

These work supports were constructed of soft materials not only to prevent scoring of the workpiece, but also to prevent the picking up of work or abrasive `materials, which would otherwise accumulate between the work support and workpiece and thus cause excessive wear of the support as well as producing a size control problem requiring continual adjustment on the part of the operator to compensate for the wear and irregularities of the work support at the area of contact.

ln addition, the possibilities of chattering between the workpiece and support were substantially enhanced when a stationary blade type support was used, and the maximum surface speed that could be tolerated between the workpiece and support were therefore limited.

The present invention offers a solution to many of these problems in the form of an improved work support having a roll at the point of contact between the workpiece and blade, the roll having a helical groove formed in its outer cylindrical surface and being journaled in a bearing har or channel along its entire axial length, such that not only will the work support be more rigid, but that accumulated abrasion and workpiece particles will be harmlessly swept away from the point of contact between the workpiece and support due to the pumping and cleansing action of the helical groove rotating in the bearing bar. in addition, the useful life of the work support will be substantially extended due to the utilization of the lower rolling coefficient of friction between the workpiece and support, and the possibilities of chatter between the workpiece and support will thus be minimized, due to the more rigid roll support, thereby permitting higher surface speeds for longer periods. Moreover, the roll and bearing bar-may be constructed of a substantially harder material than was'formerly used in the conventional stationaryrwork support blade due to the cleansing action of the helical groove in the bearing bar and the extended journal area for the roll.

Briefiy described, the present invention contemplates a conventional work rest base having an upstanding plate ICC or blade portion, which may be fastened to the base either by suitable fasteners or integrally formed therewith. The plate portion has a hardened channeled bearing bar connected thereto, along its upper surface, to receive and journal a cylindrical roll, and thereby provide a rolling contact point between the workpiece and supporting base,

according to the principles of the present invention.

The roll is substantially equal in length to the bearing bar, an-d is journaled therein along its entire axial length to thus provide the rigid work support features of the invention permitting bigger cuts and higher surface speeds of the workpiece. The end portions of the roll are inserted in a pair of associated roll supports, which prevent axial shift of the roll in the bearing bar during operation.

The helical groove in the outer cylindrical surface of the roll coacts with the workpiece and bearing, to provide a cleansing and pumping action along the point of contact between the workpiece and roll, such that displaced workpiece or abrasive fragments will either be entrapped in the groove and carried away from the contact point with the flow of coolant which lls the groove, or swept away from the point of co-ntact due to the action of the roll in the bearing bar.

Thus it will be appreciated that the work support of the present invention not only provides a cleaner contact surface between a workpiece and the work support of the present invention, but also permits a longer useful life of the work support before servicing or replacement is necessary, as well as reducing the amount of adjustments normally required to compensate for wear in a stationary type work support, while at the same time permitting higher surface speeds without: the danger of chatter, due to the utilization of a rolling point of contact between the support and the work.

lt is an object then of the present invention to provide an improved work support.

Another object of the present invention is to provide an improved work support utilizing a rolling point of contact between a workpiece and the work support, thereby permitting the use of a harderl material at the point of contact between the workpiece and support to thus extend the overall useful life of the work support assembly,

A still further object of the present invention is to provide an improved work support that will minimize the accumulation of undesired work and abrasive particles at the point of contact between the workpiece and work support, that will permit higher surface speeds between the workpiece and support, that requires fewer adjustments to compensate for wear and that is easy to service and maintain.

,Another object of the present invention is to provide a work support having a cylindrical roll journaled for` rotation in the support, the roll having a helical groove formed in its outer surface to effect a pumping action at the point of contact between a workpiece and the roller, and thereby cleanse the surface of the roll and harmlessly carry away displaced work and abrasive particles from the area of contact betweenthe workpiece and roll, to thereby reduce the tendencies of chatter between the workpiece and support and extend the useful life of the work support assembly.

Another object of the present invention is to provide a work support having a relatively hard roll supported" along its entire length in a relatively hard bearing to thus form a stronger and more rigid Work'support for a workpiece. j

Many other objects and advantages of the present invention will become manifest to those versed in the art upon making reference to the accompanying drawings and detailed description which follows, that forni apart of this specification. l

In the drawings:

Figure 1 is a front elevational View of the work support assembly of the present invention, showing the relativepositionof the roll lini-a bearing bar, and showing in phantom, `the operating position `of anassociated workpiece;

Figure 2 is an enlarged cross-sectional view substantially along the line Il-II 'of Fig. l;

Figure?) is an elevational View of the roll of the improved work support assembly of the present invention, showing the helical groove formed in the outer cylindrical surface of the roll; and

Figure 4 is an end elevational view of the work support assembly of the present invention, showing in phantom the relative position of the workpiece when engaged between the tractor and grinding wheels of an associated centerless surface grinder.'

As shown on the drawings: In Fig. l, the work support assembly of the present invention is comprised generally of a base pad P, that includes; an upstanding plate portion p, an elongated bearing bar B that is mounted on the plate portion p, acylindrical roll R that is supported by the bearing bar B and a pair of roll supports S that maintain the roll R in journaled relationship in the bearing bar B. A typical workpiece W, as for example a poppet type automotive valve, is illustrated in phantom as it would be supported during a grinding operation.

The base pad P may be formed in any desired shape, depending upon the particular work location and application of the work support assembly 10, but as illustrated in Fig. l the base pad P is formed with a substantially 4rectangular lower portion 11, having lateral end extremities 12 extending on either side of the upper plate portion p to facilitate securement and fastening of the base portion 1.1' to a suitable holder (not shown) adjacent the work station.

The upper plate portion p may similarly be of any desired configuration, but is illustrated in one exemplary form in Fig. 1 as a rectangular tapering plate (Figs. 2 and 4), having generally vertical lateral edge portions 13 and al horizontal upper surface 14. The upper surface 14' may be groovedto a generally V-shaped configuration as at 16 (Fig. 2) in order to facilitate attachment of the bearing bar B to the upper plate portion p, as by brazing or welding, though any other conventional fastening techniques could also be employed.

The base pad P, including the upper plate portion p, may be formed of any suitable material that is sufficiently strong to support the associated workpiece W at the work station without chattering or excessive vibration during a heavy cut, andof such material as to resist the corrosive effects of the cooling lubricant and temperature conditions present at the work station.

Referring now to Figure 2 in conjunction with Figure v.1, the bearing bar B isformed with a length substantially equal to the lateral width of the upper plate portion p of the bearing pad P, and has a generally rectangular cross-sectional configuration (Figure 2) that includes a pair of vertical sidewalls 17, `a V-shaped lower surface 18 that is complementally formed to the V-shaped groove 16 in the upper plate portionv p, and a generally horizontal at upper surface 19. The lower surface 18 of the bearing bar B is formed with a V-shape to permit a more rigid brazed or welded 4connection between the bearing bar B and the upper plate portion p,-as well as insuring an accurate alignment of these components during assembly of the work support assembly 10.

.As best shown in Figure 2, the flat upper surface 19 of the bearing bar B is axially grooved as at 20, preferably to a hemispherical yshape and having a radiussubstantially equal to the radius-.of theroll R, the groove 20 extending across the full axial length of the bearing bar (Figure 1).

It should be noted that the center vfabtnlt which the bar B is somewhat above theiplane line of the flat upper surface 19, and is also displaced somewhat rearwardly of the midpoint of the fiat upper surface 19 of the bearing bar B, thereby defining a forward at upper surface 19a and a rearward flat upper surface 19h, the forward surface 19a being substantially wider than the rear surface 19b and thus forming a shelf or table to collect work and abrasive fragments that have been dislodged during the grinding operation. The forward shelf surface 19a of the bearing bar B may thus be conveniently cleaned by wiping or with an air jet to remove accumulated work and abrasive particles from time to time, that may not have been swept away by the fiow of coolant or the relative movement of the roll R in the hemispherical journal ing groove 20.

Thus the hemispherical bearing gro-ove 20 serves not only to journal the roll R for rotation with the workpiece W, thereby substantially reducing the wear on the roll R, but also to sweep displaced work and abrasive fragments from the. outer cylindrical bearing surface of the roll R, as well as providing a more accuratework support fixture requiring little or no adjustment.

The bearing bar B may be formed from any suitable material, but is preferably-formed from a hardened wearresistant and corrosion-resistant metal, as for example carbide, thus providing the extended wear characteristics of the work support assembly 10 of the present invention, though it should be understood that any other suitable material might be employed instead, depending upon the particular operating conditions expected.

Referring now to Figure 3 in conjunction with Figures 1 and 2, the roll I has a generally cylindrical configuration and is formed with an axial length somewhat longer than the width of the upper plate portion p of the bearing pad assembly P, and the bearing bar B (Fig. l). The roll R has its external circumferential surface 21 and end extremities 22 ground and polished to a smooth machine finish, to minimize frictional forces and to insure a full length axial bearing support of the roll in the bearing bar B when mounted between the supporting blocks S (Figs. l and 2).

As best shown in Fig. 3, the outer cylindrical surface 21 of the roll R receives a helical groove 23 that extends across the full axial length of the roll R. The groove 23 is of a relatively shallow depth and is formed for example with a hemispherical crossesectional configuration (Fig. 2) and an axial pitch of one inch per revolution for the general length and diameter of the roll R illustrated in Figs. 1 and 3.

It should be understood that the depth, cross-sectional configuration and pitch of the groove 23 may be varied in accordance with the length, diameter, surface speed and working conditions to be expected in a particular installation, and that a multiple-groove construction could also be utilized in order to most advantageously exploit the self-cleansing features of the work support construction of the present invention.

Thus it will be appreciated that when the grooved roll l?. is seated. in the axial hemispherical bearing groove 2G so as to be rotatable with the workpiece W, the rotating sweeping action of the groove 23 as it enters and leaves the bearing surface Ztl generates a pumping action across the outer surface 2,1 of the cylindrical roll R. This pumping action is extremely advantageous in carrying out theprinciples of the present invention, in that dislodged work or abrasive particles will be carried away from the line of surface contact between the roll R and workpiece W, thereby increasing the cleansing action across `the cylindrical roll surface 21 than would otherwise be provided by the mere rotation of the roll R in the bearing bar journalling groove 2,0.H

In addition, cooling lubricant will ,continuously flow through the` groove 23 across the full axial length of the rollR duringa grinding operation, thus at alltirnes assuring adequate cooling and lubrication at the point of surface contact between the work support assembly 10 and the workpiece 11, and thereby also reducing the possibility of chatter or vibration of the workpiece W in the Work support assembly 10.

The roll R may be formed of any suitable material having good wear and corrosion-resistant characteristics, depending upon the particular working conditions to be encountered, but is preferably formed from a hard abra sion-resistant metal, such as carbide, and is ground and polished to a smooth machine finish to assure a precise alignment and contact with the workpiece W.

The roll support blocks S may be formed of any suitable bearing material to engage the end extremities 22 of the bearing roll lR and thereby prevent any axial shift of the roll R in the bearing bar B, the support blocks S not being subject to any Work load imposed on the roll R.

To this end, the support blocks S are bored as at 24 (Figures l and 4) to a diameter substantially equal to the diameter of the roll R, and are counterbored as at 26 to facilitate machining of the end wall of the bore 24 to a at surface, such that when the roll support blocks S are engaged against the lateral edge portions 13 of the upper plate portion p, the roll R will be restrained at its end extremities 22 against axial shift in the bearing bar B by the flat end wall retaining surfaces or" the bore 24 during a grinding operation.

The roll support blocks S may be detachably connected to the upper plate portion p in any conventional manner, but are preferably secured thereto by a plurality of removable fasteners 27, as for example metal screws, which engage appropriately threaded Ibores 28 in the upper plate portion p.

As previously mentioned, the roll support blocks S may be formed of any suitable material that is strong, corrosion-resistant, and affords a bearing action for the roll R, as for example cast iron.

In operation, after the work support assembly 1t) has been assembled according to the general arrangement illustrated in Figure l, and positioned at a work station, such as between a tractor wheel t and a grinding wheel g (Figure 4) of a centerless grinder, or the like, the work rest assembly lt) will be ready for operation according to the principles of the present invention. When properly positioned, the work support assembly l@ will support the workpiece W somewhat above the center lines of the tractor wheel t and grinding Wheel g (Figure 4) the respec tive tractor and grinding wheels being so positioned as to maintain the center line of the workpiece W over the geometric center of the fiat upper surface 19 of the bearmg bar B, this particular position of the Work support assembly 10 being necessary not only to assure a driving relationship of the roll R by the workpiece W duringthe grinding operation, but also to enhance the cleansing action of the roll surface 2l and the accumulation of displaced work and abrasion particles on the forward flat upper shelf surface 19a of the bearing bar B.

The flow of cooling lubricant over the roll R, together with the pumping action afforded by the helical groove 23 sweeping across the hemispherical journaling groove 20 in the bearing bar B, thus exert a continuous cleansing and pumping action at the surface of Contact between the work-piece W and the roll R, thereby reducing wear on the roll R, substantially eliminating chatter of the workpiece, minimizing maintenance and adjustment of the work support assembly l at the work station, as well as increasing the overall accuracy of the grinding operations.

The utilization of the hernispherical journaling groove 20 throughout the full length of the bearing bar B, permits heavier cuts to be taken by the grinding Wheel Without the danger of chattering or excessive wear of the work support assembly by distributing the grinding stress loads more uniformly across the bearing bar B and upper plate portion p, and should replacement of the roll R be necessary, substantial time savings are realized in that the roll support blocks S may be readily removed and the roll R replaced without a complete dismantling of the work support assembly l0.

Thus it`will be appreciated that the work support assembly 10 of the present invention provides many novel advantages over the conventional centerless grinding type work support devices, heretofore used.

It should be understood that variations and modifications may be effected without departing from the scope of the novel concepts herein disclosed.

We claim as our invention:

l. A work support assembly adapted for use with a centerless grinder, or the like, comprising a base, an upstanding support member carried by said base, a bearing bar having an axial hernispherical recess formed therein carried by said supporting member, a generally cylindrical roll having a helical cleansing groove formed in its outer surface journaled in said bearing bar for rotation with an associated workpiece, said groove being cooperable with said bearing bar to cleanse the outer surface of said roll of foreign particles during a grinding operation, and detachable roll support means maintaining said roll journaled in said bearing bar.

2. A Work support assembly comprising a base, an upstanding support plate carried by said base, an elongated bearing bar carried by said support plate, said bearing bar extending across the full length of said support plate, a hemispherical recess in the upper surface of said bearing bar and extending the full. length thereof, a work supporting cylindrical roll journaled in said recess in said bearing bar for rotation with an associated workpiece, said supporting roll having a helical cleaning groove formed in its outer surface cooperating with saidbearing bar to cleanse the outer surface of said roll, and means for maintaining said roll journaled in said recess in said bearing bar.

3. A Work support assembly adapted for use with a centerless grinder, or the like, comprising a base, an upstanding support plate carried by said base, an elongated bearing bar carried by said support plate and'having a width substantially equal to the lateral width of said support plate and extending the full length of said support' plate, said bearing bar having an axial. hernispherical recess formed in the upper surface thereof and extending the full length thereof, a cylindrical roll journaled for rotation in said hemispherical recess of said bearing bar, said cylindrical roll having a helical cleaning groove formed in the outer surface cooperating with said hemispherical recess in said bearing bar to cleanse the outer surface of said roll, said hernispherical recess extending across the full length of said bearing bar having a radius substantially equal to the radius of said cylindrical roll, and detachable roll supporting blocks embodying a bore substantially equal to the diameter of the ends of said cylindrical roll and in Contact with the ends of said roll for maintaining said roll journaled in the hemispherical recess in said bearing bar.

4. A work support assembly comprising a base, an upstanding support member carried by said base, a one piece bearing bar extending across the full length of said supporting member and carried by said support member, an axial hemispherical recess formed in the upper surface of said bearing bar and extending the full length thereof, a cylindrical roll supported along its axial length by said recess in said bearing bar and journaled for rotation therein, said hemispherical recess having a radius substantially equal to the radius of said cylindrical roll,l said cylindrical roll having a helical cleaning groove formed in the outer surface cooperating with said hemispherical recess in said bearing bar to cleanse the outer surface of said roll, and detachable roll support blocks embodying a bore substantially equal to the diameter of the end portions of saidvcylindrical roll and in contact with the end portionsofsaid roll for maintaining said roll journaled in said recess in said bearing bar.

5. A work" support assembly comprising a base, an upstanding support member carriedrby said base, a single bearing bar extending across thefull length of said support member and having an axial hemispherieal recess formed in its-upper surface, said bearing bar rigidly secured to and carried by said support member, a cylindrical roll seated in the hemispherical recess in said bearing bar Vand journaled for rotation therein along its aaial length, the hemispherical recess having a radius substantially equal to the radius of said cylindrical roll, said cylindrical roll having a helical cleaning groove formed in the outer surface cooperating with said hemispliercal recess in said bearing bar to cleanse the outer surface of said roll, and detachable roll support blocks embodying a` bore substantially `equal to the diameter of the end portions of said roll and in Contact with the end portions of said roll for maintaining said roll journaled in said recess in said bearing bar.

6. A work support assembly comprising a supporting member, an elongated bearing carried by said support member, said bearing extending the entire length of said support member, said bearing having an axial hemisplieri` cal recess formed therein, a generally cylindrical roll having helical cleaning groove formed in its outer surface supported along its axial length by said bearing and journaled for rotation in said recess therein, said helical groove being cooperable with said bearing to cleanse the outer surface of said roll of foreign particles when rotating with an associated workpiece in said bearing, and means maintaining said roll journaled in said bearing.

7. A Work support assembly adapted for use with a centerless grinder, comprising a base, an upstanding support member by said base, a V-shaped groove in the having a V-shapedlovver surface andgan axial he'misphe'rical recess in its upper surface carried by saidhsuppo'rt member, a'generally cylindrical ifollhaving afhelical cleansing groove formed in its outer'surface journaleld` in said recess in said bearing bar for rotation with an associated workpiece, said groove being cooperable withjsaid bearing bar to cleanse the outer surface Aof `said roll of `foreign particles during a grinding operationjand roll supporting means in contact with the end portions thereof for maintaining said roll journaled in the recessrin said bearing bar.

8. A Work support assembly adapted for use with a centerless grinder, comprising a base, an upstanding support member carried by said base, a Vshaped groove in the upper surface of said support member, a bearing having a V-shaped lower surface and an aXial hemispherical recess in its upper surface carried by said support member, a generally cylindrical roll having a Vhelical cleansing groove formed in its outer surface journaled in said recess in said'bearing bar for rotation Withan associated workpiece, said groove being cooperable with said bearing bar to cleanse the outer surface of said roll of foreign particles during a grinding operation, and detachable roll supporting means in contact with the end portions thereof for maintaining said roll journaled4 in the recess in said bearing bar.

References Cited in the le of this patent UNITED STATES PATENTS 1,393,046 Singer Oct. l1, 1921 1,676,620 Norton July 10, 1928 2,332,528 Rauschenberger Oct. 26, 1943 2,474,138 Zimmerman June 2l, 1949