US1646801A - Grinding machine - Google Patents

Description

1 646 801 Oct. 25, 1927' D. VAN NORMAN ET AL I GRINDING MACHINE Filed May 19. 1922 4 Sheets-Sheet I,

L v INVENTOR j 8 Oct. 25 I927. 1,646,801

F. D. VAN NORMAN ET AL GRINDING MACHINE Filed-May 19. 1922 4 Sheets-$heet 2 INVENTOR' %7 BYm f ATTORNEYS Oct. 25,1927. 1,646,801

' F. D. VAN NORMAN ET AL GRINDING MACHINE Filed May 19. 1922 4 Sheet s-Sheet 3 ATTORNEYS Oct, 25, '1927.

F. D; VAN NORMAN ET AL GRINDING MACHINE Filed May 19, 1922 4 Sheets-Sheet 4 ATTORNEYS Patented Get. 2.5, 1927.,

pantie rnnnnnron D. van Norman AND enonen w. FLEMING, or ernrnerrntnivrnssnonnsnr'rs, assrenons TO van Noem -in Macninn root ceMranY, or emine- FIELD, MASSACHUSETTS, A CORPORATION or MASSACHUSETTS.

GRINDING MACHINE.

Application filed May 19, 1922. Serial No. 582,104.

This invention relates to improvements in grinding ma chines.

According to one feature of this invention, a grinding machine is provided which con sists of a plurality of units, each of the vertical type, which are arranged in a compact group and may be mounted on a common base and driven from a common source of power, preferably self contained in the machine, as an electric motor.

F or example, by this arrangement three grinding units of the vertical type may be arranged into such small compass as to cocupy no more floor space than one grinder of the horizontal type of like capacity. Aside from the desirable feature of economy in floor space, the three units are grouped so closely together that one man may not only operate all three but may continually have all three machines under close observation.

According to another feature of the invention, the machine has a main power shaft which is common to all the units and is suil ably driven, preferably by an electric motor. and a series of driving shafts, one for each unit and each arranged. to be driven independently of the other from the main power shaft, whereby any one or more of the units may be operated, as desired.

According to another feature of the invention, a grinding machine is provided wherein the work-head and wheell1ead are relatively movable in a vertical direction, and the movable head, together with the parts carried therewith, such as a rotary spindle and driving mechanism therefor, is balanced on its ways by distributing the weight of the head and parts carried thereby equally on opposite sides of said ways.

According to a further feature of the invention, the movable head is also counterbalanced. on its utys against vertical movement.

Acrxn'ding to another feature of the invention, the whe l-head is mounted on one side of a *arriage, which is slidable intermediate its ends on vertical. ways, and on the opposite side of said carriage, a driving means, preferably an electric motor, is mounted.

According to other features of the invention, provision is made for cross feed movement of the work-head or wheel'head, either or both. and provision is likewise made for quickly movingcithcr the wheel head or work head into offset relation with the other,

and for rapidly bringing them back accurately into their original positions.

Other features and advantages will appear in the following description and in the illustrative embodiment of the invention in the accompanying drawings, in which:

Fig; l is a front elevational view of a multiplc grinding machine embodying the invention; 7

i Fig. 2 is a fragmentary plan view, with parts broken away, of the rear portion of the machine, illustrative of the common driving means for the several units and the manner in which power from such means is distributed to the several units;

Fig. 3 is an enlarged side elevational view, with parts in section, of the lower portion of one unit of the machine;

Fig. at is a fragmentary sectional plan view, illustrative of the driving connections for the work-holder;

Fig. 5 an enlarged side ele ational view of the upper portion of the machine;

Fig. 6 is a sectional plan view illustrative of the wheel-head and associated parts;

Fig. 7 is a sectional plan view illustrative of the driving connections for the wheel spindle;

Fig. 8 is a fragmentary sectional plan View of the means for releasing the wheel-head from its feeding mechanism; and

Fig. 9 is a fragmentary view taken on the line 9'-9 of Fig. 3.

Referring to these drawings, the machine includes a series of units (three as shown) mounted on a common base A. All of these units are alike, so that one only need be described in detail, and each unit is a complete grinding machine in itself and may be used independently of the others, if desired. Each of the unit grinding machines is preferably of the vertical type, as indicated in Fig; 1, to afford a very compact arrangement and one in which the three machines occupy no more floor space than a single machine of like capacity and of the horizontal type. Aside from the saving of floorspace, which most important, the compact arrangement shown is desirable to permit one operator to ei'licicntly attend a number of machines. The three machines are grouped together closely enough to allow the necessary close observation of the work being performed by the three machines.

Each of these units includes a hollow base frame B within, and on the back of which,

, most of the driving mechanism is located.

A single driving means, such as an electric motor M supplies power to all the units.

As shown in Fig. 3, motor 14 is mounted on a pedestal G located at the rear of the bed A and is provided with a pulley 15 which by means of a belt 16 drives a pulley 17 on a shaft 18 extending horizontally along the rear wall of the three frames B adjacent the bases thereof. Above shaft 18, a series of axially aligned shafts 19, one for each unit, are mounted and each shaft 19 carries tight and loose pulleys 20 and 21, eitherrof whichmay be connected by a belt 22 to correspondingpnlleys 23and 24, respectively,

.feeding movements of the former. V The pulley is fixed to a shaft 82 suitably mounted in frame B and this shaft is the driving shaft for rotating the work-holder spindle.

The work-holder, of any desired type, may be suitably secured to the work-holder spindie 34, which, as shown, has a threaded upbest shown in Fig. 4.

per end for such purpose. The spindle '34 1 rotatably mounted and vertically disposed in a work-head and at its lower end carries a pulley 36 which is connected by a belt 37 to a pulley 38 on the driving shaft 32, al-

ready described. This belt 37 necessarily has to make a quarter turn and desirably passes over two idler pulleys 39 and 40, as These pulleys are mounted on studs '41 secured in a bracket 42 pivoted at 43 to the work-head 35 and a spring 44, connected at one end to the workhead and at the other end to bracket 42, urges the pulleys 39 and 40 against the belt. The particular mounting of these pulleys as described is desirable to compensate for movement of the work-head in a direction parallel. with the axis of shaft 32.

The work-head 35 may be mounted on frame B in many various ways, as desired, and thedriving connections for the workholderspindle 34 have been designed to per mit movements of the work-head relatively to the frame, which movements are fre quently, althoughnot always, desired. In the drawings, several examples of frequently desired movements are shown, and any one or more may be utilized as desired. Thus,

direction for the purpose of moving the work-holder at right angles to the axis of the grinding wheel, which as will appear, is located above the work-holder spindle. and with its axis vertically disposed.

One of these slides, as 50, is arranged to be moved automatically by small increments for cross-feeding purposes by a more or less commonanechanism exemplified in Fig. 3. A lead screw 52, rotatably mounted in frame B, engages a nut 53 on slide 50 and this lead screw is connected by gearing 54 to a shaft 55 whichcarries a ratchet 56. ,T he latter is intermittently turned, and when so turned, moves the slide in a manner too well known in the art to require complete detailed illustration and description here. Ratchet 56 1s provided with the usual holding pawl 57 and a second pawl 58 pivoted to one end of a lever '59 pivoted intermediate its ends to frame B and arranged with its other end in the path of a reciprocablemember 60. The latter periodically engages and depresses the last named end of lever 59 thereby causing the pawl 58 to turn ratchet 56 through an angularincrement which, as will appear, is

variable as desired. On an upward movement oftlie reciprocable member 60 the pawl 58 is moved back by gravity, the left hand portion of the lever andthe pawl 58 overbalancing the other end of the lever. The member 60 takes the form of a rod, having a screw threaded connection with a bracket 61, and is thereby adjustable to vary the time and by loosening bolt 62, bracket 61 may be swung on this bolt as a pivot into a position such that it will not engage lever 59 and may be held in this new position by tightening bolt 62. p

The other slide 46 is provided in cases where it is desired to move the work holder rapidly into an offset relation with the 65, threaded into slide 46 and bearing at its inner end against slide 50. Also an abutment is provided on one slide to engage the other slide and define the relative positions in which they should be locked together by screw Thus, a screw (56 threaded into a lug 67 onslide 50 is arranged to engage one end of slide 16. F or moving slide 46, a lever (38 is provided, which is pivoted to frame B at one end and pivot-ally connected,

as by a link (39, to the slide. On releasing screw (:35, lever 68 may be swung to the left (Fig. 1) to move slide 16, and thus the work holder, into the desired offset position. In returning slide 16 to its normal position, lever 68 is moved until the slide abuts screw 66 after which the screw istightened, whereby slides db and 50 may be clamped together in the same relative positions which they originally occupied.

superposed upon frame B is a second frame I) whichon its front face is provided with two laterally spaced and vertically extending ways 70, as best shown in Figs. 1 and 6. Upon these ways a carriage 71 is slidably mounted, and upon Ways 72 provided on the carriage, a slide 73 is mounted for horizontal movement. A second slide 74 may be mounted on ways 75, provided on slide 73, if desired. The slide 74 rotatably supports a vertically disposed wheel spindle 7 6 which carries at its lower end a grinding wheel 77 and atits upper end a pulley 78.

Secured to carriage 71 and extending rearwardly thereof inside frame D is a frame 79 upon which is mounted an electric motor 80, preferably in a manner to permit adjustment as by the bolts 81 passing through slots 82 in the base of the frame. A screw 83, rotatably mounted but not axially movable in a lug 84 on frame 7 9, is threaded into the base of motor to permit the latter to be conveniently adjusted back and forth on frame T 9 when bolts 81 are loosened. The shaft of motor 80 carries a pulley 85 which is connected by a belt 86 to the pulley 78 described. A belt tensioning device is provided such as an idler pulley 87 mounted on one end of a lever 88, which is pivoted intermediat its ends at 8.9 to the top of carriage 71 and connected at its other end by a spring 90 to the carriage. The spring urges the idler against belt 87 to tension it at all times and compensate for movement of slide 7%, this arrangement being particularly desirable where a quick acting offset movement of the slide is desired.

A quick acting means for moving slide 74: to carry wheel 77 into offset relation to the work spindle may be provided, which is generally similar to that described for the work head. Thus, slide 7 1 normally abuts a stop, such as a screw 91 (Fig. 6) carried by slide 7" and is clamped thereto as by a screw 92 (lfig. 5). A lever 93 (Fig. 1), pivoted to carriage 71, is connected to slide 74, as by a pin and slot connection 94., whereby when screw 92 is loosened, lever 98 may be swung to move slide 74: rapidly to the left (Fig. 1). In returning slide 74, lever 93 is swung until the slide abuts screw 91, after which screw 92 is tightened to clamp slides 74: and 73 together in the same relative positions which they originally occupied.

Automatic crossfeeding means may be provided for moving the slide 73 and thus the wheel 77, one example of such means being shown in Figs. 5 and 6. Thus, slide 73 carries a nut 94:, and engaged therewith, 1

is a lead screw 95 rotatably mounted, but not axially movable in the carriage 71. The latter, as indicated inlFig. 6, is suitably recessed to receive these elements. The lead screw 95 is connected at one end by spur gears 96 to a stub shaft 97 which is rotatably mounted in a bracket .98 secured to can riage 71, and upon this shaft is fixed a ratchet wheel 99 and a hand wheel 100 (Fig. 0) the latter being employed for manually moving the slide when desired. An actuating pawl 101, pivotally connected to the free end of an arm 102 pivoted to bracket 98, is arranged to be lifted by a pin 103 mounted to slide vertically in the bracket and limited in its descending movement by a collar 104: on its upper end. Pin 103 is preferably adjustable, as to length, by means of an ex tension 105 threaded therein. The lower end of the member 105 is adapted, on descent of carriage T1, to engage an abutment 106, which is mounted on a vertical rod 107 and adjustably secured thereto, as by the clamp ing screw 108. The rod 107 is mounted in brackets 109 secured to frame D. The time at which the abutment 106 is enga-ged by member 105 may be varied by adjustment of the former on rod 107, and by varying this time of engagement, the movement of pin 103 and thus the throw of pawl 101 may be varied. The abutment 106 may be moved angular-1y out of the path of member 105 when this cross-feeding movement is not desired.

The carriage 71 and the attached motor supporting frame 7 9 are arranged on opposite sides of ways 70 and preferably the weight these elements and the parts carried thereby is distributed, as nearly as possible, equally on opposite sides of these ways. The result of this arrangement is a balancing of the carriage and its attached parts, which if perfectly performed will relieve the ways 7 0 from pressure and therefore minimize wear. The carriage 71 can be made to enga e its ways with very little allowance for clearance and yet avoid the binding action which would otherwise occur, and a closer fit between the ways and carriage means improved accuracy in the work performed.

The carriage 71 is preferably also balanced against movement on its ways 70, or more properly its weight, including attached parts, is counterbalanced by a weight 115 (Fig. so that the carriage will tend to remainin any of the positions to which it may be moved. This arrangement reduces the effort required to raise the carriage and relieves the mechanism, used for vertically moving it, from a considerable weight or pressure Which would tend to cause rapid wear. The counterbalance 115 is preferably guided on' a rod 116 fixed to, within, and near the rear of frame D and is connected by a chain 117 to carriage 71, the chain passmg over one or on frame D.

The carriage 71 is moved on its ways by, a vertically reciprocable rod 119, which is slidably'mounted in frame B (Fig. 3) and extends upwardly into frame D, passing loosely through the motor supporting frame 79, as indicatedv in Fig. 6. Adjustably fixed on rod 119 is acollar 120 (Fig. 8) whichhas afgr'oove 121 in its periphery disposed at right angles to the axis of rod 119. Slidably mounted in carriage 71 is a pin 122, one end of which is adapted to engage in groove 121 to lock the carriage thereto. spring 123 more sheaves 118 mounted 11 is provided, which tends at all times to urge pm 122 toward rod 119, and a lever 124 pivoted intermediate its ends to the carriage has a pin and slotconnection 125 with pin 122, whereby the latter may be withdrawn from groove 121 to release the carriage 71 for manual movement. For effecting such movement, a hand wheel 126 (Fig. 1) is provided on the end of a shaft 127 which is rotatably mounted in frame D and extends into the interior thereof, as shown in Fig. 5. On shaft 127 and within frame D is a pinion 128 which meshes with a rack 129 secured to the carriage 71 as shown in Fig. 6.

The means for automatically reciprocating rod 119 may take various forms, as desired, and one suitable form is given by way of illustrative example in Figs. 3 and 9. Pivotally'connected at one end to a collar 130 on rod 119 near the lower end thereof is a link 131 which extends downwardly and is pivotally connected to a slide 132. The latter is dovetailed to fit. over ways 133 formed on one face of a lever 134 pivoted at 135 to frame B, within which all the actuating mechanism for rod 119 is located. A lead screw 136 is rotatably mounted, but not axially movable, in one end of lever 134 and engages in a nut137 carried by slide 132. Bymeans of a hand wheel 1.38 on screw 136, the latter may be conveniently turned to adjust the slide 132 along lever 134 and vary its distance from the pivot 135 and thereby vary the throw imparted to link 131 and rod 119. The lever 134 carries on its opposite face a roll 139 which rides in a path cam ing movements'may be efiected manually or automatically as desired. The automatic crossfeed for both the work-head and wheelhead may be temporarily disconnected, when desired. When one is used, the other is disconnected and when hand-feeding is desired, both may be disconnected. Also both wheelhead and work-head areprovided with means for quickly moving the wheel and work-head into off-set relation. Either of thesequick acting means may be used, as

desired. The relative vertical movement between the wheel and work-head may be effected either manually or automatically, and as shown, is eftectedby moving the wheel-head. The workhead also'may be adjusted so that its axis lies in angular relation with that of the wheel head. It will thus be seen that the machine has considerable flexibility and may be operated in various ways as desired. The general operation of the machine will be obvious from the fore going description.

The invention has been disclosed herein for illustrative purposes but the scope of the invention is defined by the appended claims rather than by the foregoing description.

l Vhatwe claim is: v

1. In a grinding machine, a frame, a work head and a wheel-head mounted thereon one vertically above the other, one of said heads being vertically movable to and from the other, a rotary spindle in each head, means for moving one of said heads transversely relatively to its spindles axis for cross-feed ing purposes, and quick acting means for moving the last named head transversely to offset its spindle from the spindle in the other head. I

2. In a grinding machine, a frame includand the latter slidably mounted on said ways, a rotary spindle mounted in each of said devices, means for adjusting the workholding device on said frame to permit the work holding spindle to be moved angularly of the tool carrying spindle, means for n'ioving the slidahle device on its ways, and means for moving one of said devices transversely to the direction of travel of the slidable device on said ways.

4:. In a grinding machine, a frame having an upwardly extending portion provided with ways, work-holding and tool-carrying devices, the former mounted on said frame and the latter slidably mounted on said ways, a rotary spindle mounted. in eachof said devices, means for adjusting the work holding device on said. frame to permit the work holding spindle to be moved angularly of the tool carrying spindle, means for moving the slidable device on its ways, means for moving one of said devices transversely to the direction of travel of the slidable device on said ways, and counterbalancing means for supporting the slidable device in any of the various positions to which it may be moved on said ways.

5. In a grinding machine, a hollow, boxlike pedestal provided with an opening in one vertical face thereof and ways on said face on each side of said opening together with ways on the vertical walls of said opening, a carriage mounted for vertical recipro- 'ating movement on said ways, a rotary spindle mounted in said carriage, a motor support secured to that portion of the carriage disposed between the ways and extending into said. hollow pedestal, a motor the carriage disposed between the ways and extending into said hollow pedestal, a motor mounted on said support, driving connections between the motor and spindle, a weight to counterbalance the carriage slidable in the hollow pedestal out of the path of the motor support, and a flexible connection between said weight and carriage.

T. In a grinding machine, a base having an upwardly extending portion with slide ways thereon, a slide supported for vertical movement on said ways, a wheel head mounted on said slide for movement in a direction right angularly to the direction of the first named ways, a work head supported on a vertical face of said base for adjustable movement on an axis angularly to said face, a rotary spindle in each of said heads, means for driving said spindles and reciprocating means for the wheel head.

in testimony whereof we have affixed our signatures.

FREDERICK D. VAN NORMAN. GEORGE W. FLEMING.

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