US1905651A - Safety device for grinders - Google Patents

Description

2' Sheets-Sheet 1 A ril 25, 1933. c; T. RAULE SAFETY DEVICE FOR GRINDERS Filed March 2, 1929 A TTORNEY INVENTOR 0/4 TZPau/e A ril 25, 1933. c. "r; RAULE 1,905,651

SAFETY DEVICE FOR GRINDERS 4 Filed March 2, 1929 2 Sheets-Sheet 2 IN VEN TOR- A TTORNE Y Patented 1933 PATENT 0FFlCE- CLIFFORD '1. RAULEQOI' BBOOKLINE, PENNSYLVANIA.

sum nnvrcnron enmnnns Application filed Iaroh 2.1929. Serial No. 343,878.

My invention relates to internal grinding Describing in illustration and not in limimachines with particular reference to an automatic safety device.

A purpose of my invention is to revent the wheel unit ortions of the in ividual grinder units 0 a multiple unit internal grinder from moving to normal. inding position if the conditions are not rlghtfor grinding, either by reason of the wheel Having finally worn away to a redetermined limit of safety or by reason 0 a work piece having been inserted imperfectly into the work-holder portion of the unit.

A further pur ose is to latch the grinding wheel portion 0 any grinder unit of a multiple spindle grinder away from its. normal grinding position by an engagement between an imperfectly inserted work piece and latch operating'mechanism having preferably either electric or mechanical connection with the latch.

A further pur ose is to latch the grinding wheel portion 0 any grinder unit of a multiple spindle grinder away from its normal grinding position by the engagement between normally spaced members supported respectively upon the wheel unit and its slideway carrier, and operating preferably either electrically or mechanically to hold the unit from its normal grinding osition.

Further purposes will appear in t e specification and in the claims.

I have elected to show two only of the 'many difierent forms in which my invention may be embodied, selecting forms that are efiicient in operation, inexpensive to manufacture and which will illustrate the principles of my invention.

Figure 1 is a broken and somewhat diagrammatic top plan view of a multiple spindle internal grinder having applied to it one form of my invention.

Figure 2 is a verticalv section-of Figure 1.

Figure 3 is an enlarged vertical section showing the same grinder machine as is seen in Figure 2 but having applied to it a different form of my invention.

Like numerals refer to like parts in all figures.

tation and referrin to the figures:--

I have illustrate my invention embodied on one of the forms of multiple grinder shown in my copending a plication No. 126,- 403-entitled Grinder Mi led August 2, 1926. The invention is applicable 7 to multiple grinders of widely different types, but showing it embodied'with a form 0 grinder disclosed and described in detail in said application makes it less necessary to go into detailed description of structure that is in itself not part of the present invention. The ,mvention is well adapted for use with any one of the forms shown in said application, and to many other forms of grinders not there shown.

Multi le machine The grinding machine is intended to operate upon duplicate work pieces which are continuously fed to grinder units of the machine as. the pass a loading oint and are discharged 0111 the same umts after having been ground to finished size as the units pass an uhloading point preparatory to again reaching the loading point.

The machine :com rises a plurality of grinding units space around a turn-table that is mounted upon suitable stationary supporting structure. The grinding operations at each unit begin when-the unit receives a work piece as it passes the charging or loading point and finally end at the unit with the removal of the finished work piece from the unit while the unit is passing the unloading point.

Each grinder unit comprises a work-holder unit adapted to rotate during the travel of the turn-table and a wheel unit adapted to present a rapidly revolving and vertically .traversing grinding wheel to the work throughout the grinding portion of the orbit.

A common feed cam mounted upon the stationary supporting structure causes the traversing wheels to" travel successively around the same orbit. The wheels initiall enter the work interiors out of contact wit the work surfaces and feed progressively at some point before the unloading grinding begins.

to a predetermined finish size. This occurs has been reached. There the wheel units successively rise to be out of the way for the unloading and subsequent loading operations. ey-remain raised until they reach a point somewhat beyond the loading point in the direction of travel, and then again move down for traverse grinding.

My safety device is adapted to operate upon the individual units while assing a paint of their common orbit that 1s located yond theloading point but not so far beyond it. as is the point at which traverse In the illustration the turn-table 5 is pivoted upon a stationary central post 6 of stationary supporting structure 7 and is rotated by a suitable motor 8 mounted upon the base of the central post and geared at 9 to-rotate the turn-table.

The work-holders 10 may be of any suitable type and are shown continuously rotated by individual motors 11 mounted upon downcooperating engagement between a commonwardly extending portions 12 of the turn table and holders.

Each wheel unit l t-"1s supported in a horizontal guideway 15 that extends outwardly from a carrier 16 with which it is rigidly connected and the individual carriers 16 are adapted to vertical reciprocation along vertical traverse guideway standards 17 of the turn-table. v

The grinding unit carrier 16 is'positioned geared at 13 to the respective and traverse motion of the wheel 1s eflected ,by cooperating engagement between a suitable stationary upwardly directed undulatorycam '18 surrounding the central axis of the turn-table and rods 19. These rods ing lugs 20 of the carriers 16, through suitable perforations21- in thelower portion'ofthe turn-table to rest upon the cam surface 18. v

The wheel units are fed to the work by a cam 22 mounted 'upon the stationary supporting structure, and the outer ends of the feedrods 23 adjustably threaded into the individual wheel units.

I guideways.

As thewheel wears away, by reason of grinding and diamonding, the feed arms 23 must be gradually lengthened to maintain station.

. the

safety device adapted to o asslngbetween the "grinding-to exact size. This lengthenin is conveniently effected automatically by a eed engagement between the teeth of the star wheels 25 and one or more projecting pin or pins 26 on the supporting structure, the wheel being desirably diamonded after such feed to insure exactly proper alinement of rinding element. 7 A l of the foregoing has beendescribedin greater detail in my prior 'application.

The present invention is directed at. a rate upon the individual units while positions for feeding 1n new work pieces and that for the initial entry of the wheels for traverse grinding. In the plan view Figure 1 the work pieces are fed into the successive holders at a suitable platform 27 and traverse grinding normally begins at some point 28 that is'some littledistance beyond the position for feeding in the new work pieces.

The improper condition for grinding'may result from an imperfect insertion ofla work piece or from a grinding wheel hav-' effective grinding.

In either case my device prevents the wheel unit from moving down into the posiplatform 29 placed suitably back of the loading platform, the wheel carrier is raised into position to lift 'the wheel out of the way above the work-holders and it normally remains in its raised position until some time after a new work piece has been inserted and until the point 28 is reached.

I mount a movable arm 30 across the common path of the upwardly projectin ends 31 of the work piecesin a position t at is somewhat before the point 29 at which the wheel carrier normally starts down for-traverse grinding, and somewhat after the loadingposition 27.

The arm 30, conveniently pivoted to a lug 32 of the stationary supporting structure, presents an upward bevel 33 toward the approaching work pieces, riding over their projecting ends with or without contact.

The workpieces that have been properly positioned in their respective hplders pass under the arm 30 without lifting it to any material extent. 1

If however a work piece has not" been properly inserted inits holder its lower end does not lie flush with a circumferential seat (not shown) provided for it in the holder. As a result the upper end of the piece projects abnormally and when the piece.

passes under the arm it raises the arm to a greater extent than is the case when the piece is roperly seated in its holder. fuse this abnormal movement of the arm 30, which takes place only .in the event of 5 an improper seating of the work piece to prevent the usual return of the carrier 16 to its position for traverse grinding.

I do this in any suitable way, in Fi re 2.

closing an electric circuit to electrica' y opo erate a latch 34 and inFi 3 using the upward movement of the arm to mechan bracket '38 on the turntable and carries a.

lower book 39 adapted to swing under a downwardly directed abutment 40 when the ma et is energized.

he carrier is normally supported and traversed by the rod 19 the bottom of this rod resting upon the surface of the traverse cam 18. When the bottom of the rod reaches the descending portion 41 of the traverse cam, the carrier normally thenmoves down into position for traverse grinding but if an abnormal condition at the unit has operated the latch, the carriers abutment 40 comes down upon-the hook 39 which then supports the carrier, the bottom of the rod remaining somewhat abovethe upwardly presented surface of the cam.

The latch may be made operative under any number of diiferent contingencies likely to produce abnormal conditions at the unit.

Of these different contingencies the most usual is that of an imperfect seating of a work piece in its holder and that of a wheel having gradually wornaway to an extent that it is no longer effective to properly grind and in Figure 2,1 show the same latch 34 operated if either one of these contingencies take place.

As the wheel gradually wears away the position of the wheel unit along its horizontal guidewa is gradually changed, the wheel unit being ed inwardly along its guideway by the star wheel 22 which engages the feed pin 26. w V v 'After the wheel has been reduced in size to a predetermined limit contact members 42 and 43 respectively mounted upon the wheel unit and its carrier make contact, closing an electric circuit through the magnet 36 and operating the latch to prevent the return of the carrier to grinding position after the insertion of a work piece.

55 -It will be noted that in the illustration the individual electromagnets 36 are connected in parallel to a suitable battery 44. The other side of the battery is grounded at 45 and the other side of the magnet goes to ground through the contact members 35 when there has been an imperfect insertion of a work piece or through the contacts 42 and 43 if the wheel is wornaway to its predetermined lower limit.

In the structure shown in Figure '3, I use mechanical means for operating the latch latches may be operated by the different abnormal conditions under which it is desired to prevent the return of the wheel unit to its grinding position.

The latch 34' comprises a bell crank rock- ,34' and illustrate that the sameor separate er pivoted at 46 to a portion of the tlll'n- 1 table and presenting an upwardl extending arm: 47 to engage the carrier an a horizontal outwardly extending arm 48 to be engauged by the inner endof the arm 30:

The hub of the rocker is provided with adj acent V-notches 49 and 50 that alternatively receive the. beveled end of a click member 51 s ring-pressed into one or other of the note es.

. The click member is normally in the lower notch and in this position the upwardly pre sented arm 47 is out of the way of the carr1er permitting the carrier to move down to grinding position without striking.

The arm 30 is preferably angularly adustable at 52 as to initial posit-ion, which s set so that the work pieces properly seated in their respective holders successively engage without materially raising the arm.

If a work piece is inserted imperfectly in its holder its top unduly projects upwardly, raislng the arm 30 as it passes under which in turn angularly deflects the rocker bringmg the upper notch 49 into position to receive the cllck member 51 which further defleets the rocker into a position at which the top of the vertical arm 47 is latched under a downward abutment 40' of the carrier, preventing the carrier from going down into position fortraverse grinding.

In Figure 3 the carrier is provided with a horizontal bolt 53 provided with adjacent V- notches 54 and 55 that alternatively receive the beveled end of a click member 56-springpressed at 57 into one or other of the notches.

The point of the click is normally in the right-hand notch and the bolt 53 does not any wheel unit safely away from its carrier from moving down to position for. traverse grinding.

' abnormal conditions under which the wheel is maintained safely away from grinding position have been an imperfect seating of the work piece in its holder and the reduction in size of the wheel through use to a predetermined limit beyond which it is considered inadvisable to use the wheel for grinding.

These two abnormal conditions are the most usual ones that make it undesirable to .permit the grinding wheel to descend to grinding position, and while I have not illustrated the invention applied for operation in the presence of other disadvantage ous abnormal conditions I contemplate doing so whenever such conditions arise.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying; the structure shown, and I, therefore,-claim all such in so far as they fall within the reasonable spirit and scopeof my invention. Having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1.;In ;a multiple grinder, a turn-table, grinding units mounted on the turn-table spacedtherearound, each unit comprising a revolving work-holder and a grinding wheel, supporting structure for the turntable having unloading and loading points for the units adjacent oneside of the table, and mechanism for moving the wheels suscessively away from the grinding position before the unloading point-isreached and back into grindingposition after the'loading point has beenlpassed, in combination with a safety device for preventing the movement of a grinding wheel to its grinding position preparatoryto initially grind ing the work and operative by meansof an abnormal condition at the unit.

2. In a multiple grinder, a turn-table,

grinding units-mounted on the turn-table spaced therearound, each unit comprising a revolving work-holder and a grinding wheel, supporting structure for the turntable having unloading and loading points forthe units adjacent one side of the table, and mechanism for-moving" the wheels successively. away from the grinding position before the unloading point is reached and prevent a grinding revolving work-holder and a grindin wheel,

supporting structure for the turn-ta 1e having unloading and loading points for the units adjacent one side of the table, and mechanism for moving the wheels successively away from the grinding position before the unloading point is reached and back into grinding position after the loading point has been passed, in combination with mechanism adapted to movement of the wheel to its grinding position preparatory to initial grinding comprising a latch, connections between the latch and wheel adapting the latch to maintain the wheel in raised position, an electromagnet adapted to operate the latch, an electric circuit adapted to operate the magnet and contact means for closing the circuit operative preparatory to initial grinding and after loading by an abnormal condition of the unit. I

4. In a multiple grinder, a turn-table, grinding units mounted on the turn-table spaced therearound, each unit comprising a revolving work-holder and a grinding wheel, supporting structure for the turn-table having unloading and loading points for the units adjacent one side of the table, and mechanism for moving the wheels successivel away from the grinding position before the unloading point is reached and back into grinding position after the loading point has been passed, in combination with mechanism adapted to prevent the movement of the wheel to its grinding position comprising a latch, connections between the latch and wheel adapting the latch to maintain the wheel in raised position, an electromagnet adapted to operate the latch, an electric circuit adapted to operate the magnet, and contact means for closing the circuit operative by. an abnormal extension of a work piece if the work piece is imperfectly seated in its holder and other contacts for closing the circuit operative by an inward extension of the wheel unit whenthe wheel is worn away to a predetermined limit. a

5. In a multiple grinder, a turn-table, grinding units mounted on the turn-table spaced therearound, each unit comprising a revolving work-holder and a grinding wheel, supporting structure for the turn-table having unloading and loading points .for the ,units adjacent one side of the table, mechainto its position prevent the nism for moving the wheels successively away from the grinding position before the unloading point is reached and back into grinding position after the loading point has adapted to prevent the movement of the wheel to its grinding position including a latch to maintain the wheel in raised position, an electromagnet to operate the latch, an electric circuit, and contact means for closing the circuit operative by a work piece if the work piece is imperfectly seated in its holder and other contact means for closing the circuit operative by the wheel unit when the wheel unit reaches a predetermined position upon its carrier.

6. In a multiple grinder, a turn-table, grinding units mounted on the turn-table spaced therearound, each unit comprising a revolving work-holder and a grinding wheel, supporting structure for the turn-table having unloading and loadin points forthe units adjacent one side 0 the table, and mechanism for moving the wheels successively away from the grinding position before the unloading point is reached and moving 'it back into grinding position after the loading point has been passed, in combination with a click latch adapted to latch the car rier in raised position and means operative by an abnormal condition at the unit for. operating the latch.

7. In a multiple grinder, a turn-table, grinding units mounted on the turn-table spaced therearound, each unit comprising a revolving work-holder and a grinding wheel, supporting structure for the turn-table having unloading and loading points .for the units adjacent one side of the table, mechanism for moving the wheels successively away from the grinding position before the unloading point is reached and moving it back into grinding position after the loading point has been passed in combination with a click latch adapted to maintain the carrier in raised position, and means operated by the upper end of a work piece if the work piece has been imperfectly seated in its holder for operating the latch.

8. In a multiple grinder, a turn-table, grinding units mounted on the turn-table spaced therearound, each unit comprising a revolving work-holder and a grinding wheel, supporting structure for the turn-table having loading and unloading points zfor the units adjacent one side. of the table,.and mechanism for moving the wheels successively away from the grinding position before the unloading point is reached and .back into grinding position after the loading point has been passed, in combination with a safety device adapted to prevent the 9. In a multiple grinder, a turn-table, grinding units mounted on the turn-table spacedtherearound, each unit comprising a revolving work-holder and a grinding wheel,

been passed, in combination with mechanism supporting structure for the turn-table having loading and unloading pomts for the units adjacent one side of the table, and mechanism for moving the wheels successively away from the grinding position beforethe unloading point is reached and back into grinding position after the loading the latch.

CLIFFORD T. RAULE.

return of a grinding wheel to its grinding position when the wheel has worn away to a v predetermined limit.

Images