US1535080A - Means for controlling feeding mechanisms - Google Patents

Description

April 21, 1925.

1,535,080 H K. SPENCER MEANS FOR CONTROLLING FEEDING MECHANISMS 5 Sheets-Sheet 1 Filed July so, 1921 .Henryl jispe?u;er

April 21, 1925. 1,535,080

H. K. SPENCER MEANS FOR CONTROLLING FEEDING MECHANISMS File July 1921 5 Sheets-Sheet 2 lnveni'ow f Z@ Z Hera-311'. S o 021L 62, /5/ y a April 21, 1925. 1,535,080

H. 'K. SPENCER MEANS FOR CONTROLLING FEEDING MECHANISMS File July 0, 1921 5 Sheets-Sheet 4 177/276311770? I Henry K.S;aen0en April 21, 1925. v

" H. K. SPENCER MEANS FOR CONTROLLING FEEDING MECHANISMS 5 Sheets-Sheet 5 Inveniow:

HenqyILSpenc-er, 27y Co r Patented Apr. 21, 1925.

UNITED STATES arent HENRY K. SPENCER, OF WATERTOWN, MASSACHUSETTS, ASSIGN'OR TO THE BLANCH- ARD MACHINE COMPANY, OF CAMBRIDGE, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

MEANS FOR CONTROLLING FEEDING MECHANISMS.

Application filed July 30, 1921. Serial No. 488,747.

To all whom it may concern:

Be it known that I, HENRY K. SPENCER, a citizen of the United States, anda resident of VVatertown, in the county of Middlesex and State of Massachusetts, have invented an Improvement in Means for Controlling Feeding Mechanisms, of which the following description, in connection with the accompanying drawings, is a specification, .like characters on the drawings representing like parts.

This invention relates to means for controlling a working function of a machine, and is more especially concerned with a feed control for metal working machines such as surface-grinders. The invention will be best understood by reference tothe following description'when taken in connection with the accompanying drawings of one specific embodiment of the means by which the method may be carried out, while its scope will be more particnarly pointed out in the appended claims.

In the drawings,

Fig. 1 is a skeletonized elevationpartly in section of a portion of a grinding machine equipped with a feed control exemplifying the invention, some parts of the machine being slightly rearranged as compared with their arrangement in practice, this being done for convenience and clearness of dis closure; 7

Fig. 2 is a diagram of-tlie electrical connections of the feed control;

Fig. 3 is a plan of that portion of the feed control which directly cooperates with the work. the same being shown on a lunch enlarged scale;

Fig. 4-. is adetail elevation of the work engaging shoe and its carrier as viewed in the direction of the arrow 4; in Fig. 3;

Fig. 5 is a detail elevation of some of the parts shown in". Fig. 3 viewed in the dircction of the arrow 5; i

Fig. 6 is a detail elevation of sonie of the parts shown in Fig. 3 viewed in the direction of the arrow 6;

Fig. 7 is a detail plan on an enlarged scale of one of the electrical contacts shown in Fig. 3;

Fig. 8 is a detail plan section illustrating the other electrical contact shown in Fig. 3:

Fig. 9 is a detail sectional view on line 9-9 of Fig. 3;

Fig. 10 is an elevation on an enlarged scale of some of the parts shown at the upper right-hand portion of Fig. 1;

Fig. 11 is a plan of the parts shown in Fig. 10;

Fig. 12 is a detail sectional view on line 1212 of Fig. 11; and

Fig. 13 is a detail sectional view on line 13-13 of Fig. 10.

Referring to the drawings and to the embodiment of the invention which is selected for exemplification, there is shown a portion of a metal working tool of the class represented by U. S. Letters Patent No. 1,182,861. dated May 9, 1916, commercially known as the Blanchard vertical surface grinder. The general characteristics of the grinding machine will first be described, followed by a description of the feed control.

Referring to Fig. 1, the machine comprises a suitable. work support, herein a rotary chuck or turn table 15, which in practice is usually magnetic the better to enable it tohold small pieces of work with out the necessity of employing-clamps. The chuck is mounted to rotate about a vertical axis and is provided with driving mechanism, including a ring gear 17 meshing with a driving pinion 19. the latter being secured to'a. shaft 21, to which is also secured a mit're gear 23 which meshes with a mitre gear 25. The latter is secured to and driven by a horizontal shaft 27, which in practice may be driven at various speeds through the use of a change speed mechanism, a por tion only of which is shown herein, the same comprising a spur gear 29 secured to the. shaft 27 and meshing with a spur gear 31 secured to and driven by a main driv ng shaft 33' having a driving pulley 35.

screw 51, to which is secured a bevel gear 53* meshing with a-beveled pinion 55, the latter being secured to a horizontal shaft 57, to which is also secured a mitre gear 59 which meshes with a mitre gear 61. The latter is secured to a shaft 63 to which is also-secured a. ratchet feed wheel (iii-cooperating with a spring pressed pawl 67. A pawl carrier 69 is in the form of a lever mounted to rockabout' the axis of the shaft 63 and is swung to and fro by a link 71, provided with a slot 73 which receives a crank pin .75 carried by a crank 77, the latter being secured to a shaft 79. Also secured to this shaft is a worm gear 81 meshing with a worm 83 which is secured to a vertical shaft 8,5,to the lower end of which is also secured a mitre gear 87 meshing with a mitre gear 89 secured to and driven by the shaft 27.

The operation of the machine as thus far described will nowbe described. The chuck is rotated in the direction of the arrow A in Figs. 1 and 3 and the abrasive wheel 37 is preferably rotated in the direction of the arrow B. Work pieces 91 are placed upon the face of the chuck and the rotation of-the latter brings them successively befneath the abrasive wheel, whose action reduces the thickness of the pieces. The amount of material which is taken off is dependent upon the vertical position of the abrasive wheel and is determined by the feeding mechanism. As the grinding operation proceeds the abrasive wheel is gradually lowered through the action of the feeding mechanism in the following manner. The power which is transmitted to the worm 83 rotates the latter and causes the ro-v tation of the worm gear 81, the shaft 79 and the crank arm 77. The crank pin 75 engages the upper end of the slot 73 and moves the link 71 in an upward direction, thus giving the pawl carrier 69 and pawl 67 an upward stroke which causes the ratchet fee-d wheel to beturned an amount corresponding to such stroke. When the crank pin passes beyond its uppermost position, and starts to travel in a downward direction the link, pawl carrier and pawl will follow by the action of gravity until their downward movement is limited by a stop 93. The rotation ofthe feed wheel which has thus taken place is transmitted through the mitre gears 61 and 59, shaft 67, bevel pinion 55 and bevel gear 53 to the feed screw. 51 which, being held against movement in a vertical direction, imparts a vertical movement to the nut 49 and wheel head 47. The amount of feed is determined by the position of the stop 93 which of course determines the stroke of the feed pawl.

The means for controlling the position of the stop will now be described, reference being had first to Figs. 10 to 13, inclusive. The stop. 93 is suitably mounted for movement into and out of the path of a lug 95 carried by the pawl carrier 69, and in the present example this is conveniently accomplished by making the stop in the form of a plate which is disposed in a general horizontal position and is mounted to slide in a general horizontal direction in and out with reference to the pawl carrier. The plate is mounted upon a guide 97, herein formed as.

a part of a supporting bracket 99, which is preferably mounted for adjustment about the axis of the pawl carrier. Referring to Fig. 13 which shows this construction inplan section, the adjustable bracket 99 constitutes a slide having surfaces 101 guided by an arc-shaped guide 103, whose center is the axis about which the pawl carrier swings. This guide is herein formed on a plate 105 which is fixedly secured as by screws 107 to the framework 109 of the machine (see Fig. 11). The plate 105 is herein provided with a lug 111 constitutingv a pointer provided with the reference mark 113 to assist the operator in'setting the feed wheel. Likewise the guide 103 is provided with suitable graduations 115 cooperating with the lug 95 to assist the operator in setting the'bracket 99. Referring to Fig. 13, the latter is normally held in the selected position of adjustment by a clamping screw 117 having screw threaded engagement with the bracket as at 119, and adapted to engage the guide 103 thereby to clamp the bracket thereto.

\Vhen, however, the stop 93 isplaced in its forward position represented in Fig. 10, it is in the path of the lug 95 carried by the pawl carrier 69 and thus limits'the downward swing of the latter. the stop is Withdrawn rearwardly 01; toward the right in Fig. 10, the downward stroke of the pawl carrier is limited only by its engagement with the guide 97 on which the stop 93 slides. When this takes place the pawl carrier has a greater stroke and imparts to the abrasive wheel a correspondingly greater amount of feeding movement. If desired I may employ an auxiliary stop 93-similar to and superposed uponthe stop 93. lVhen the auxiliary ,stop is brought forward into the path of the lug and the pawl carrier, the stroke of the latter is naturally limited to a still greater extent. In the present example the auxiliary stop .lV-hen, however, 1

Inc

test ed is adjustably positioned upon the main stop by providing the former with two holes 121 and 123, either of which is adapted to receive a pin 125 which is also received in a hole 127 provided in the main stop. A screw-129 threaded into the guide 97 is received in slots 131 and 131 provided in the stops 93 and 93 respectively. When it is desired to bring the auxiliary stop 93 forward into alignment with the main stop 93 this may be accomplished by simply lifting the auxiliary stop from its engagement with the pin 125 and sliding the same forward until the hole 123 comes into registration with said pin and then dropping the auxiliary stop so that the pin enters said hole.

The movement of the stop into and out of the path. of'the pawl carrier may be controlled by the condition of the work, and the reduction of the thickness of the latter to the predetermined dimension may be utilized in some suitable way to bring the stop forward into position where it will modify or altogether stop the action of the pawl carrier. 4

In the present example, the position of the stop is controlled by a lever 133 which carries the pin 125 and is fulcrumed on a pivot 135 gn the bracket 99. The latter is provided with a slot 137 (see Fig. 12) in Secured which the pin plays to and fro. to the lever is an. armature 139 cooperating with the pole pieces 141 of a magnet 143 mounted on the bracket 99.

A suitably arranged spring 145, the load of which may be adjusted by an abutment 147 carried by an adjusting screw 149, constantly tends to move the armature away from the magnet and to carry the stop into the path of the pawl carrier. "When, however, the magnet is energized it attracts the armature 139and overcomes the spring 145, thus causing the stop to be withdrawn from the path of the pawl carrier. The making and breaking of the magnet circuit may be accomplished by suitable means, now to be described, controlled by the condition of the work, reference being had first to Figs. 3 and 4.

A suitably shaped follower or shoe 151 is adapted to ride upon the upper surface of the work which travels. relatively thereto, and the frictional resistance to such movement is utilized to control the feed. To this end the shoe is mounted upon a carrier 153 which is movable in a general direction lengthwise of the travel of the work. Referring to Fig. 9, in the present example the shoe is secured to the carrier by providing the latter with a slot 15 5 which receives the shoe, the latter being clamped in place by one or more, herein a plurality, of set screws 157. These screws may be caused to urge the shoe into the slot by providing each screw with a conical point 159 received in a conical recess 161 provided in the shoe and so placed that the conical point of the screw is offset. in an upward direction from the axis of depression. It follows that the inward movement of the screw is accompanied by upward movement of the shoe in the slot. The shoe is therefore gradually positioned and firmly held in place in itscarrier.

Referring now to Fig. 6, in the present embodiment the carrier 153 is formed as a part of a lever 163 which is fulcrumed on a pivotal mounting, as, for example, a pair of conically shaped pivots 165, which is mounted for axial adjustment. in lugs 167 formed on a bracket 169. The latter in turn is received in a groove 171 provided in a collar 173 in which it is fixedly secured by screws 175.

The collar 173 is mounted for vertical ad justment upon a suitable fixed support,

herein a post 177. In the present example,

this is accomplished by the use of an adjusting nut 179 having screw threaded engagement with the post and serving as a stop against which the collar 173 is urged by a spring 181 interposed between the bottom of the collar and an abutment 183 at the bottom of the post. The collar has splined connection with the post, as by a key 185 (see Fig. 3). It follows that rotation of the adjusting nut 179 is accompanied by vertical movement of thecollar 173. The latter is herein split as at 186 and is provided with a clamping screw 187, by means of which it may be caused to grip the post 1'77 more or less firmly as circumstances may require. If desired, the adjusting nut may be provided with suitable graduations 189 and the collar 17 3 with the cooperating reference mark 191, although these are not at all essential as the adjustment will be usually accomplished by trial of the shoe against a test piece of known thickness placed upon the chuck. The shoe will be adjusted until it just touches againstthe top of the test piece without suflicient frictional resistance to cause it to be dragged along during the rotation of the chuck.

Referring to Fig. 3, movement of the shoe in the direction of travel of the work is resisted by a suitable spring 193, the resistance of which may be varied by an adjustable abutment 195, herein carried by an adjusting screw 197 having screw threaded engagement with the lever 163. When in the operationof the machine a work piece. having passed beneath the abrasive wheel and still being of greater thickness than the test piece by which the shoe is adjusted, passes beneath the latter the frictional resistance overcomes the resistance presented by the spring 193 and causes the lever 163 to be rocked in a clockwise direction, as viewed contact member 199- is provided with a binding post 209 having, anut 211 by means of which a terminal lead wire 213 may be secured thereto.

Referring again to Fig. -3, the contact 201 is preferably yieldingly mounted,

as by being secured to one arm of a U-shaped I whose other arm is secured to a bracket 217, which in turn is secured tothe collar 173.' Thus in the operation of the machine when the contact 199 brings up against the contact 201, the latter yields to an extent limited by 2. preferably adjustable stop, herein a screw 219 threaded into the bracket 217. The latter is provided with a binding post 221 having a nut 223 by means of which the terminal of a lead wire 225 may be secured thereto.

Referring now to Fig. 2.21s a diagrammatic illustration of the electrical circuit, there is suitably interposed in the latter a source of current such as a battery 227. lVhen, now, the circuit is closed by the contact 199 bringing up against the contact 201, the magnet 143 is energized and attracts the armature 139, thus'causing the spring 215,

l movable stop 93 to be withdrawn from the path of the pawl carrier.

This condition will continue until the abrasive wheel has removed suflicient stock from the 7 work pieces to reduce their thickness to the test pieces which are employed in setting the shoe, whereupon the frictional resistance heretofore tending to drag the latter along no'longer exists and the spring 193 asserts itself and swings the lever 163 to its normal position, thereby moving the contact 199 away from the contact 201 and breaking the circuit. whereupon the feeding mechanism either reduces or altogether stops 'the' feed of the abrasive wheel toward the work.

Having thus described one embodiment of the invention but without limiting myself thereto, what I claim and desire by Letters Patent to secure is:

1. In a machine for reducing a body by the removal of material therefrom, the combination of a reducing tool, means to cause a relative travel of said tool and the material in the direction of the surface of said body from which the material is removed,

means to cause. a relative feedof said tooland the material in a direction transverse to said surface, a follower adapted to rest against said surface, and means for utilizing the frictional resistance to relative movement of said follower and said surface of said body in the first-named direction to control said feed.

2. In a machine for reducing a body by the removal of material therefrom, the combination of a shoe resting against said body, and means for utilizing the frictional resistance to the relative movement of the shoe and said body to control the operation of said machine.

3. The combination with a machine having a tool for removing material from a travelling work surface, of a shoe resting againstsaid surface, and means for utilizing frictional resistance to the relative movement of the shoe and work surface to control the amount of material removed from said surface.

4. In a feeding mechanism, the combination of feeding means having a positive movement in one direction and a non-positive movement in the oppositedirection, and means movable into and out of the path of said feeding means in its non-positive movement.

5. In a feeding mechanism, the combination of feeding means comprising driving and driven parts, said driving part having a to-and-fro movement and said driven part havifigan intermittent movement in one di rection, means for imparting to said driv-. ing part a positive movement in one-direction while permitting a non-positive movement in the opposite direction, and means movable into and out of the path of said driving part in its non-positive movement.

6. In a feeding mechanism, the combination of feeding means comprising driving and driven parts, said driving part having a to-and-fro movement and said driven part having an intermittent movement in one direction, means for imparting to said driving .part a driving movement in one, direction and permitting a non-driving return movement, and means movable into andout of the path of said driving part in its non-driving return movement.

7. In a feeding mechanism. the combination of feeding means comprising a ratchet wheel, a pawl and apawl carrier, means for imparting to saidpawl carrier 2. driving 1 movement in the direction to cause said pawl to rotate said ratchet wheel, and to permit an idle return movement of said pawl carrier, and means movable into and out of the path of said pawl carrier in the return movement. y

8. Ina machine of the class described, the combination of a support for the work, a tool for reducing the work, means to cause a relative travel of the work and tool, means to cause a relatii e feeding of. said tool and work in a direction transverse to the first- ,mentioned travel, a shoe adapted to ride on the worksurface, a mounting on which said shoe 15 mounted for. movement lengthwise lltl of the first-mentioned travel,means to cause said shoe to rest upon the work and to be carried by its frictional engagement therewith in the direction of the travel of the work,yielding means tending to carry said shoe in the opposite direction, and means controlled by movement of said shoe to control the relative feeding movement of said tool and work.

9. The combination of a tool, a worksupport, a follower adapted to rest against the work on which said toolis operating, means to cause arelative transversing movement of said work-support and said tool and follower to cause said tool and shoe to traverse the work surface, and means for utilizing the frictional resistance to such movement to control the operation of said tool.

10. The combination of a tool, a worksupport, a follower adapted to rest against the work on which said tool is operating, means to cause a relative traversing movement of said work-support and said tool and follower to cause said tool and shoe to traverse the work surface, means to cause a relative feeding movement of said worksupport and tool transversely of said surface, and means for utilizing the frictional resistance to said relative traversing movement to control said feeding movement.

11. The combination of a tool, a follower adapted to rest against the work on which said tool is operating, means to cause a relative traversing movement of said follower and work, and means for utilizing the frictional resistance to such movement to control the operation of said tool.

' '12. In a machine for removing material from work, the combination of a follower adapted to rest against the surface from which material is removed, means to cause relative traversing movement of said follower and work, and means for utilizing the frictional resistance to such movement to control the amount of material removed. 13. In a machine for removing material from work, the combination of a tool for.

removing material, a follower adapted to rest against the surface from which the material is removed, means to cause the work to be presented first to said tool and then to said follower, and means for utilizing the frictional resistance to relative travcrsing movement of said work and follower to control the amount of material removed.

14. In a machine for removing material from-work, a tool for removing material, means for relatively feeding said tool and work, one toward the other, a follower adapted to rest against the surface from which the material is removed, means to cause the work to be presented first'to said tool and then to said follower, and means lea for utilizing the frictional resistance to work, one toward. the other, a follower.

adapted to rest against the surface from which the material is removed, means to cause the work tobe presented first to said tool and then to said follower, and means to cause frictional resistance to relative traversing movement of said'work and follower to be accompanied by operation of said feeding means and to cause cessation of such resistance to be accompanied by modification of the feeding movement.

16. The combination of a tool, a follower adapted to rest against the work on which said tool is opera-ting,,means to cause a relative traversing movement of said fol lower and work, yielding means tending to cause said follower to move in a backward direction with relation to said movement, and means rendered effective by frictional resistanceto such traversing movement to overcome said yielding means and to feed said work and tool, one toward the other, and to cause cessation of said frictional resistance to be accompanied by said yieldifng means asserting itself to modify such eed.

17. In a machine for removing material from work, the combination of a tool,for

removing the material, a follower adapted to rest against the work on which said tool is operating, means to predetermine the position of said follower toward and from the work surface and to be carried forward by frictional resistance therewith, yielding means to carry said follower backward when such frictional resistance ceases, and means controlled by the forward and backward movement of said shoe to control the position of said tool with reference to its capacity for removing material.

18. In a grinding machine, the combination of a grinding wheel; a gage; a worksupport to present the bodies to be ground to said grinding wheel and to said gage' in succession; normally inactive feeding means; means including a normally open electrical circuit controlled by said gage for causing engagement of said wheel with said bodies; a mounting permitting said gage to be dragged along by said bodies when engaged therewith and to cause the completion of said ircuit and the operation of said feeding means; and means for causing the restoratlon of said gage to its initial position when not engaged by said bodies.-

19. In a machine for reducing bodies by the removal of material therefrom, a reducing tool; a gage; 'means to present the bodies to saidreducing tool and to said gage in SIlCCBSSIOIl; normally inactive feeding means for causing arelative feeding movement of said tool and said bodies, one toward the other; and means operated hy engagement of said gage with a Work-piece to cause said feeding means to be brought into action and to-remain in action until there is a predetermined thickness of said work-piece.

20. In a machine for reducing bodies by 10 the removal of material therefrom, a remaaoeo ducing tool; a Work support; normally inactive feeding means for causing a relative feeding movement of said tool and work support, one toward the other; and means operated by a Work-piece larger than a predetermined dimension to cause said feeding means to become active.

In testimony whereof, I have signed my name to this specification.

HENRY K. SPENCER.

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