US1151785A

US1151785A - Grinding apparatus.

Info

Publication number: US1151785A
Application number: US78152913A
Authority: US
Inventors: Halbert K Hitchcock
Original assignee: Pittsburgh Plate Glass Co
Current assignee: PPG Industries Inc
Priority date: 1913-07-28
Filing date: 1913-07-28
Publication date: 1915-08-31
Anticipated expiration: 1932-08-31

Description

H. K. HITCH'COCK. GRINDING APPARATUS. APPLICATION FILED JULY 28, 1913.

Patented Aug. 31', 1915.

4 SHEETS-SHEET I.

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FIGJ.

WITNESSES H. K. HHCHCOCK.

GRINDING APPARATUS.

APPLICATION FILED 1ULY28, 1913.

Patented Aug. 31, 19 15.

4 SHEETS-SHEET 2.

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WITNESSES h? J] INVEN TOR I fl/{WW' H. K. HITCHCOCK.

GRINDING APPARATUS.

APPLICATION FILED JULY 28. 1913 P11te11tedAug. 31, 1915.

4 SHEETSSHEET 4.

WITNESSES IN'VENTOR ffi/W a: ear

PLATE GLASS COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

GRINDING APPARATUS.

Specification of Letters Patent.

Application filed July as, 1913. Serial m5. 131,529.

To all whom it may concern Be it known that I, HALBERT K. HITCH- COCK, a citizen of the United States, residing at Tarentum, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvementsin Grinding Apparatus, of which the following is a specification.

The invention relates to mechanism for grinding surfaces, particularly of plate glass. It has for. its primary objects; (1) the provision of improved means for adjusting the drive of the runners so that their greater abrading action may be directed at any portion of the sheet of glass requiring such action; (2) the provision of improved means for securing the attachment of the runners to and their disengagement from their supporting means, and (3) the provision of compact and eflicient means for regulating the pressure of the runners upon the glass being ground, the said means being constructed so as to prevent fracturing the glass due to excessive pressure being eoncentrated upon the high places by the runners as the glass rotates there-beneath. Certain embodiments of the invention are illustrated in the accompanying drawings, wh'erei.n'

Figure 1 is a partial section and partial side elevation showing the general arrangement of the parts, Fig. 2 is an enlarged section taken on the line II-II of Fig. 1, Fig. 2 is an enlarged detail partially in section of the bypass construction in Fig. 1, Fig. 3 is a section similar to that of Fig. 2, but taken through a modified form of construc tion, Figs. 4 and 5 are sections taken on the lines IV1V and V-V respectively of Fig. 8, Fig. 6 is a plan view of the central portion of the runner with the parts for supporting it removed, Fig. 7 is a partial side elevation and partial section showing the general arrangement of another modification of the structure, Fig. 8 is an enlarged section through the spring cylinder and parts contained therein, and Fig. 9 a partial side elevation and partial section of another modified type ofthe apparatus.

Referring first to the construction as shown in Figs. 1 andEZ; 1 is a portion of the table of the apparatus, which is rotated in the usual way and may be of any approved type; is one of the runners; 3 is the builtup girder or framework from which the run- Patented Aug. 31, 191.5.

ners are suspended, such girder being supported at the ends by means of the uprights '3 5 is the bar or post by means of which the runner 2 is suspended from the box girder or bridge 3; 6 is a plunger or piston supported upon the lower member of the girder 3 7 is a cylinder-or annular-chamber fitting over the plunger or piston (3 and keyed to the post 5; 8 is a pneumatic hydraulic tank from which the cylinder 7 is supplied with fluid through the pipe 9; 10 is a handwheel by the operation of which the engagement and disengagement of the post 5 with respect to the runner is secured; and 11 is another handwheel by the actuation of which the rotary adjustment of the post 5 with respect to the runner 2 is secured in order to enable the operator to shift the position of the portion of the runner which bears hardest on the glass during the period when the runner is being lowered and before the total weight is applied, thus increasing. and decreasing the drive of the runner at will.

Mounted rotatably in a recess in the center of the runner 2 is the hearing and supporting block 12 around which the runner 2 rotates. This block is held in position in its recess by means of the plate 13 which overhangs the upper edge of the block and is securedto the runner by means of the bolts 14 and 15. The supporting bar or post 5 is rectangular in cross section, and is provided along one side at its lower end with a projecting rib l6 fitting in a groove in the block 12. The rib is held in position in its groove by means of the key 17 having its lower end 18 tapered, and its upper end 19 is turned laterally to receive the screw 20 carried by the handwheel 10. The nut 22 just below the end 19 prevents downward movement of the key 17 with respect to the handwheel 10. It will be seen that by operating the handwheel 10 to raise the key 17 the lower end of the key 16 withdrawn from the socket in the block 12, thus providing room to permit the post 5 to move to the right and release the rib 16 from its groove. 7

Secured to.the upper end of the post 5 is the gear 23, such gear being held in position with respect to the upper frame member bymeans of the nut 24', and being operable from the worm Q-Lt having driving connection with the shaft 25. The shaft Q-2 5 is operable from the hand' fvvheel 11,' so

"i that by rotating handWheel-"thepost 5 and'th'e block be given any, de-.

sired degree of rotation. The purpose of this rotation of the post is to secure an adjustment of the drive'of the runner 2 with respect to the table 1. The rib 16 is off center with respect to the centerline A of the runner, so that the runner is eccentrically supported, and the side of the runner farthest removed from the rib tends to drop down and bear harder on the glass when the weight of the runner is partially sup-- portedon the rib 16, that is, during the starting up of the grinder. By rotating the post 5 and changing the point of eccentric support of the runner, the runner may be made to bear heaviest upon any' desired point of the table, thus shiftingthe driving as above described. The depending, sleeve sage, 28 connecting with the pipe 9. other end ofthe pipe 9 is-conne'cted to the 45-- 7 gives a very rigid support for the" post adjacent the block 12, and the uprights 3 (Fig. 2) connect the horizontal beams constituting the girder 3. I

In order to regulate the amount of pressure between the runner and the glass on the table, the plunger 6 and cylinder 7 are provided, the plunger $3 being supported upon the girders 3, and the cylinder 7 being keyed to the post 5 as indicated at 26(Fig. 2). Packing 27 for the plunger is provided, and fluid is admitted to the space between the plunger and cylinder through the praistank 8, and this tank, 8 is supplied with water under pressure, by means of the pipe 29 leading to an accumulator-or any other desired source of fluid pressure,'and controlled by a threeway hand valve (not shown). The space above the water 30 or other liquid in thetank 8, is filled with air and constitutes with respect to the plunger and cylinder an air spring for securing a resilient application of power tending to raise the post 5 and the runner 2 carried thereby. A throttling valve 9 is placedin the pipe 9 (Fig; 2 and serves to regulate the resistance of the Water flowing from thecylinder to the tank 8. A by-pass 9 is provided around the valve and in this pipe is carried a check valve 9 which per: mits the water to flow through the by-pass to the cylinder, but prevents movement 1n ,th'e reverse direction. The arrangement allows a free flow'of water to the cylinder,

thus permitting the runner "to respond promptly to force tendin'g to raiseit,.while downward movement of the runner is resisted and made morej-gradual" throttling action. of the-T'vailve 9? When it is desired to li'ft'th into the chamber 8, reducing jithe volume of air contained therein until-"thmipressure' of the air and water is such thatthe'zwaterj. acting against the annular cylinder 7 raises erun-nerfrome the table, water under pressure isadmitted ue ltothe the runner 2. When the grinding operation I 1s first started, inorder to prevent excessive breakage where the glass has a rough s'ur 7 I face, thepressure of the runner upon the glass is applied gradually, such result being accomplished by allowing the escape of some of the water in the tank 8. The runner moves downward until it contacts with the surface of the glass, the air in the tank expanding and reducing the pressure in the tank and cylinder, thus permitting the application of a gradually increasing pressure to the glass. The rate at which the increasing pressure is applied is regulated by the rate at which the water is Withdrawn from the tank 8 and can be soadjusted that the pressure on the glass isproportional to the amount of grinding accomplished during the interval in which the increasing pressure has been applied. If desired, the flow of water from the tank'may be interrupted at anytime, thereby fixing the pressure upon the glass at a substantially constant amount, which pressure increases slightly as the runner rises, and decreases'as therunner lowers, due to the unevenness of the surface passing under the runner; Afterthe unevenness of the surface of the glass has been removed, the entire weight of the runher is permitted to rest upon the glass.

It will'be seen from the foregoing that the apparatusdescribed provides a very compact and easily operated meansforregulating the pressure of the runner upon the glass. The arrangement also tends to eliminate the fractures 'or cracks which often occur due to the momentum of the runner as it is caused to move up and down "by the uneven surface of the glass over which it tion resists any violent downward movement of the runner, as any downward movement of the runner must necessarily'cause. the expulsion of the liquid in the cylinder above the plunger, 'and this-expulsion ofthe' liquid is resisted by the friction of the liquid flowing through the pipe 9, and by the compressed air above the liquid int the tank 8. This resistance also increases with the extent of downward movement, since the air in the tank 8 is becoming more and more compressed, and therefore moreand more resistant. It will also be seen that the runner is free of any counterweight tending to increase the momentum ,Of the 111111131 when moved in either direction, so that the momentum of the runner in both directions is reduced to a minimum, and the danger of fracturing correspondingly reduced. Other advantages incident to the construction will be readily apparent to those skilled in the art.

Figs 3 to 6 illustrate a modification of the apparatus just above described. In this construction antifriction rollers 31 and balls 32 are provided to reduce the friction between the supporting block 12 and the socket of the table 2 in which the block is mounted. The construction of the post 5', the key 17, and the operating handwheel mechanism therefor is the same as heretofore described in connection with the structure of Figs. 1-

and 2. The means for adjusting the post 5 rotarily, including the gear 23' and worm 24 are the same as heretofore described, as is also the mounting of the plunger 6 and cylinder 7 with respect to the girder andsupporting post 5.

The primary distinction of the apparatus of Fig. 3 over that of Figs. 1 and 2 is in the relative arrangement of the plunger and cylinder, and in the means of operation. It will be noted that in the construction of Fig. 3 a very considerable space is provided above theplunger when the cylinder is in lowered position, which is not the case in the construction of Figs. 1 and 2. This difference in arrangement is due to the fact that in the construction of Fig. 3 the space above the plunger is larger and in itself constitutes an air chamber of sufficient volume to give the resilient support, and during the operation of supporting or partially supportingthe runner contains both air and water. The passage 28 is connected directly to an accumulator or other source of liquid pressure, and this liquid supplied to the pipe 28 serves to compress the air above the plunger (5. The air spring or cushion is in this construction therefore located in the cylinder insteadof in a separatetank as in the construction of Figs. 1 and 2. It will be seen that the apparatus issomewhat simpler and more direct in its operation than that of' Fig. 1, and that the water supplied at the top of the plunger serves as a packing means. By proportioning the ratio of the air space to the water space, it is possible to regulate the changes in pressure due to the movement of the runner toward and away from the glass. For instance the larger the air space the less Will be the variation in pressure due to the oscillation of the runner up and down. The resistance secured by the plunger and cylinder arrangement of Fig. 3 is also more resilient than that of the construction of Figs. 1 and 2, since there is no outflow of water through the passage '28 as is the case in the apparatus of Figs. 1 and 2,.a part of porting bars or posts 5 the constructionon the two sides of the table being precisely the same, aside from the size of the runners, so that a description of one runner and its supporting means will be sufficient.- The framework 3 which supports the runners is of the usual type, being carried at the ends by the uprights '4 and carrying the fulcrum brackets 33. The supporting post or bar 5 for the runner is circular in cross section and is journaled in

bearings

34 and 35 carried by the frame 3 and the downward thrust of the post is carried by the block 36 pinned to the upper end of the post. Below the block 36 is a bearing member 37 for taking the thrust of the block 36, antifriction balls being preferably interposed between the two bearing surfaces. The bearing member 37 is mounted loosely for rocking movement in the end of the lever 38. A fluid pressure cylinder 39 operating the piston rod 40 hooked to the lever 38 serves as.

a means for lifting the runner free from the table when it is desired to move the table from beneath the runner after the grinding operation is completed. At other'times no fluid is supplied to the cylinder 39, so that the movement of the lever 38 is not affected during the grinding operation by the connection 40.

The means employed for regulating the pressure of the, runner upon the glass comprises the connecting rod 41, the connecting rod 42, the cylinder 43 carried by the connecting rod 42, the spring 44 in the cylinder, and the handwheel 45'provided with nut 46 engaging the threaded portion of the connecting rod 42. The connecting rod 41 is in two parts pivoted together at 47, and the lower portion of the rod is provided with a head 48 engaging the lower side of the spring 44. The cylinder is of course free of attachment to theframe, and the portion of the connecting rod in the cylinder slides freely through the bearing portion 49 (Fig. 8).

After the previous grinding operation is completed the runner is raised by means of the cylinder 39 and the handwheel 45 is turned until the runner is held suspended by the reaction of the spring 44, at which time the fluid pressure in the cylinder 39 is released. When it is desired to start the grinding operation on the next set the hand-- wheel 45 is gradually turned allowing the .cylinder issecured rigidly to a bracket 53 carried bythe framework of the apparatus,

runner to move down and come in contact with the glass. As the grinding progresses the handwheel 45 is turned to allow the connecting rod d2 to move up, thus reducing the compression of the spring and allowing more andmore of the weight of the runner to press upon the glass. It will be seen that the spring in this construction performs precisely the function of the compressed air in the construction .of Figs. 1 and 3, that is, the spring applies a yielding resistance to the downward movement of the runner, and

. such resistance increases as the downward movement progresses. The tendency of the runner to move down suddenly and fracture the glass is thus resisted as in the other types of apparatus. It will also be seen that the adjustment of the yielding resistance by meansof the handwheel 45 corresponds in function to the adjustment secured by the valves in the constructions of Figs. 1 and 3, as such valves control the, compression of the, air by ,the water, and the air is the equivalent of the spring.

In the modification illustrated in Fig. 9, .1 is the table, 2 ,is the runner, 5 is the sup- :porting post, 38 is the lever for supporting and operating the runners, and 33 is the fulcrum bracket for the lever 38*. The supporting-post 5 is preferably of the type shownin Fig. 2, and is rotatedto secure the tilting. adjustment of the runners by means of thenhandwheel 11 conn'ecting with-the post5 bymeans of gearing corresponding tothat in Figs. 1 and The upper end of the post ,keyed to a thrust bearing member 36 -'whose flange is supported by the ropposingthrust bearing member 37 antifriction balls being interposed between the thrust surfaces. The thrust bearing memher-"37 v is connected to 'the lever 38 by means of thelink .50, while the other end of the lever 38 is connected to a connecting rod llisimilar to that of Fig. 7 and working in a cylinder 43'? with a spring 44 there- ,in similar to, the corresponding parts in Fig. 7.1 The cylinder 43 is pivoted at-rts lower .Qlld 'tlO 2lllOtl1Ql' .,CQIlIl8Ctlng rod 42 such rod constituting-the piston rod for the PlStOn 51 working, in the hydraulic cylinder. 52. The

and movements of. the piston 51 are controlled by means of a three-way valve connected to the pipe' 54 lea ding to the upper side of the piston. Thecylinder and piston 51.52 .con'stiitutea means for regulating the tensioniof the spring H, such parts taking the place of the nut and screw connection n Fig. 7, foiyadjusiing the position of the connee ting rod The actuation of the threeway valve in the pipe olqconstitutes a con- 7 venient means for adjusting the position of the piston 51, and-aside from thevfa ct that this valve is operated instead of the hand- Limst wheel 45, the operation of the apparatus is the same as heretofore described in connection'with Fig. 7.. I

\Vhat- I claim is 1. In apparatus for grinding, a rotating table for carrying the member to beground,

a runner mounted above the table,'resilient during the grinding operation, and means for varying the force exerted by the said means during the grinding operation.

3. In apparatus for grinding, a rotating table for carrying'the' member to be ground, a runner mounted above the table, resilient means placed under stress during the grinding operation and tending to oppose the downward pressure of the runner due to its weight, and means for decreasing the stress and permitting more and more of the weight of the runner to be applied to the member as the grinding progresses.

- et. In apparatus for grind-ing,a rotating table for carrying the member to be ground,

a portion of theweight thereof from the member belng gr0und.-

In apparatus for grindin a rotating table for carrying the member to be ground,

a runner mounted above the table, yielding movement of the 'iliunner and removing a 7 portion of the weight thereof from the memher being ground, and means for varying the opposing foreeiexerclsed by the said pneumatic means. I

'6. In apparatus for grinding, a rotating table for carrying the member to be ground, a runner mounted above the table, yielding pneumatic meansopposing-the downward movementof the runner and removing a portion of the weight thereof from the member being ground, and means'for supplying liquid under pressure for varying the opposing force exercised by the said pneumatic means.

7 In apparatusfor grinding, a rotating table for carrying the member to be ground,

a. 'runner mounted above the table, a pneuinatically. operated rain for opposing the downward movement of the runner and removing a. portion of the weight thereof from the member being ground, and means for supplying liquid under pressure to the interior of the ram to compress the gas v 105 pneumatic means vopposing the downward therein and increase the lifting power 0 the ram.

In apparatus for grinding, a rotating table for carrying the member to be ground,

a runner mounted above the table, a post for supporting the runner, resiliently operated means concentric with the post for applying force thereto tending to lift the runner, and means for varying the force applied by the resilient means.

9. In apparatus for grinding, a rotating table for carrying the member to be ground, a runner mounted above the table, a post for supporting the runner, and a fluid operated lifting ram concentric with the post for applying force thereto tending to lift the runner.

10. In apparati'is for grinding, a rotating table for carrying the member to be ground, a runner mounted above the table, a post for supporting the runner, and a-fluid operated lifting device comprising a cylinder and piston-concentric with the post with one of said parts fixed against movement and the other secured to the post and adapted to appiy lifting force to the post when fluid is supplied to the interior of the cylinder.

1.1. In apparatus for grinding, a rotating table for carrying the member to be ground,

by the device.

12. In apparatus for grinding, a rotating table for'carrying the member to be ground, a runner mounted above the table, resilient resistance means opposing the downward movement of the runner, and fluid pressure controlling means for regulating and varying the stress of the said resilient resistance means.

13. In apparatus for grinding, a rotating table for carrying the member to be ground, a runner above the table, a'post held against rotary movement with the runner, a supporting thrust bearing carried by the lower end of the post, and an opposing thrust bearing carried by the runner above the said supporting thrust bearing.

14. In apparatus for grinding, a rotating table for carrying the member to be ground, a runner above the table provided at its center with a bearing recess, a post held against rotary movement with the runner, a bearing block carried detachably upon the lower end of the post and held against rotative and vertical movement with respect to the said post and having a thrust bearing surface on its upper face, and a lateral bearing surface around its periphery opposing the side walls of the said recess, and a' thrust bearing carried by the table above the block and opposing the bearing surface on the block.

15. In apparatus for grinding, a rotating table for carrying the member to be ground, a runner above the table, a post held against rotary movement with the runner, a supporting thrust bearing carried by the lower end of the post, an opposing thrust bearing carried by the runner above the said supporting thrust bearing, and means whereby the 0st may be disengaged from the supporting thrust bearing.

16. In apparatus for grinding, a rotating table for carrying the member to be ground, a runner above the table, a post held against rotary movement with the runner, lateral and thrust bearings carried at the central portion of the runner, and opposing lateral and thrust bearings carried by the lower end of the said post,

1 7. In apparatus for grinding, a rotating table for carrying the member to be ground, a vertical post supported above the table and held against lateral and rotary movement, a runner swiveled upon the lower end of the post, and means for raising and lowering the post and the runner carried thereby.

l8.- In apparatus for grinding, a rotating table for carrying the member to be ground, a vertical post supported above the table and held against lateral and rotary movement, a runner swiveled upon the lower end of the post, and power means intermediate the ends of the post for moving it vertically.

19. In apparatus for grinding, a rotating table for carrying the member to be ground, a vertical post supported above the table and held against lateral and rotary movement, a runner swiveled upon thelower end of the post, and a fluid operated ram having its piston and cylinder concentric with the post for raising such post and the runner carried thereby.

'20. In apparatus for grinding, a rotating table for carrying the member to be ground, a vertical post suspended above the table and held against lateral and rotary movement, a runner above the table, a lateral and thrust bearing block supported by the lower end of the post off center with respect to the center line of the post and nonrotatablewith respect to the post, lateral and thrustbearings carried by the runner in opposition to the lateral and thrust bearings of the block, and means whereby the post may be adjusted rotarily about the center line.

21. In apparatus for grinding, a rotating table for carrying the member to be ground, a vertical post suspended above thettable and held against lateral and rotary movement, a runner above the table, a bearing blockon which the runner is swiveled concentrically, a supporting connection between the post and block off center with respect to the axis of rotation of the block, and means whereby the post may be adjusted rotarily.

22. In apparatus for grinding, a rotating table for carrying the member to be ground,

a runner above the table, means forsuspending the runner off center causing a tendency to tilt, and meansfor adjusting the off center point of support rotarily about the axis of rotation of the runner.

23. In apparatus for grinding, a rotating table for carrying the member to be ground, a runner above the table, a block upon which the runner is swiveled provided with a vertical recess and with another recess extending laterally from said vertical recess, a post having its lower end engaging the recess and partially filling it with a projection'engaging the lateral recess, and a vertically movable key slidable along the post and fitting into the space in the vertical recess alongside the end of the post.

24. In apparatus for grinding, a rotating table for carrying the member to be ground, a runner above the table, a block upon which the runner is swiveled provided with a vertical recess and with another recess-extending laterally from said vertical recess, a post supported intermediate its ends and with its lower end engaging and partially filling the vertical recess and provided with a projection engaging the lateral recess, and a vertically movable key extending longitudinally of the post and operable from the upper end thereof and fitting at its lower end into the space in the vertical recess alongside the end of the post.

25. In apparatus for grinding, a rotating table for carrying the member to be ground, a runner above the table, a block upon. which the runner is swiveled provided with a vertical recess, a non-rotatable post sup- ;ported from above and having its lower end engaging the said recess non-rotatably, inter-engaging means carried by the lower end of the post and the block whereby the block and runner are held against downward movement with respect to the post after the said means are interengaged, and a locking device for locking the post against movement tending to disengage the said means.

of the runner toward and fromthe table, a closed receptacle carrying a llqu d and havlng an air chamber, a connection for supfplying liquid from the receptacle-to the ram,

pressure to the receptacle to vary the air pressure in the said air chamber.

28. In apparatus for grinding, a rotating table for carrying the member to beground, a lifting ram for regulating the movements of the runner toward and from the table, a closed receptacle carrying a liquid and having an air chamber, a throttling connection between the ram and the receptacle for conveying liquid to and from the ram and arranged to permit a relatively free flow of liquid to the ram but to throttle the fluid as it returns to the receptacle, and means for supplying liquid under pressure to the receptacle to vary the air pressure in the said air chamber. I

29. In apparatus for grinding, a rotating table for carrying the member to be ground,

for supplying liquid from the receptacle to the ram, a throttling valve therein, a bypass with a check valve permitting liquid to pass the valve in its movement to the ram, but preventing the reverse movement through the bypass, and means for supplying liquid under pressure to the receptacle to vary the air pressure in the said air chamber. I

In testimony whereof I have hereunto signed my name in the presence of the two subscribed Witnesses.

HALBERT K. HITCHCOCK. \Vitnesses:

Anonwon'rn MARTIN, LETI'TIA A. MYERS.