US2935824A - Machine tool - Google Patents

Description

MACHINE TOOL 2 Sheets-Sheet 1 Filed June 11, 1958 OOO f l l INVENIOR. PHILIP J POBISCHUNG May 10, 1960 P. J. ROBISCHUNG 2,935,824

MACHINE TOOL Filed June 11, 1958 2 Sheets-Sheet 2 INVENTOR. PH/L/P J POE/5C HUNG United States Pat nt 2,935,824 MACHINE TOOL Philip J. Robischung, Kalamazoo, Mich., assignor to Hammond Machinery Builders, Inc., Kalamazoo, Mich., a corporation of Michigan Application June 11, 1958, Serial No. 741,257

5 Claims. (Cl. 51-266) This invention relates to multiple feeding, devices for a material cutting machine and it relates particularly to apparatus for independently feeding two or more items of work to a material cutting tool, such as a grinding wheel.

While the feeding apparatus of the invention is widely applicable to the feeding of many different kinds of materials (metal, wood, plastics and similar) and parts to a number of different types of material cutting devices, it has been particularly designed for the feeding of small workpieces, such as tool bits, to a grinding wheel, particularly an oscillating type of grinding wheel. Accordingly, one particular machine in which the invention is thus presently embodied will be utilized to illustrate the invention and the description thereof will proceed in terms of the feeding of multiple workpieces independently of each other to an oscillating type of grinding wheel. Such feeding of the workpieces may be in any timed relationship to each other, simultaneous, alternating or overlapping in any pattern or manner whatever desired or found convenient by the operator. Thus, it will be understood that such reference to a specific typeof machine is for .illustrative purposes only and is not to be taken in any sense as limiting the invention or precluding its applicability to other types of material working devices.

Referring now to the particular problem out of which the present invention arose, it has long been recognized that a face type grinding wheel is capable of performing a grinding operation on more than one unit of work at a time, especially when the workpieces involved are of a dimension which is relatively small with respect to the working area of the grinding wheel. However, in endeavoring to work out specific means by two or more power urged feeding devices could be independently utilized, there are presented a number of practical problems. Certain of these problems arise primarily out of grinding wheel for contact with the workpiece, and subsequently recapturing said liquid, or most of it, for re- .be collected by suitable means whichusually include some type of hood arranged around the grinding wheel. Such hood gathers and discharges the bulk of the liquid downwardly by gravity to a pan from which the liquid is then returned to the inlet side of a pump which again iimpels, said liquid back to the grinding wheel.

It is recognized, of course, that a small fraction of the .liquid will be converted into a mist which may escape or which may be collected by a suitable mist-collecting device, which condenses and returns as much as possible of the mist to the body of liquid for recycling. I -Iowever, a

2,935,824 Patented May 7 10, 1960 small fraction of the liquid is still frequently lost as mist or for other known reasons. Thus, it is not literally correct in most instances to refer to such liquid as being all collected, by whatever collecting mechanism is provided for that purpose, and returned for recycling. However, because by far the greater part of the liquid is colthe necessity of supplying a liquid to the face of the r piece and the grinding wheel.

lected and so returned for recycling, and since the small part-which is in fact lost does not affect either the above discussed problems or the manner in which they are solved by the present invention, the discussion hereinafter following will for convenience refer to the liquid as all being collected and returned for recycling, and such reference will be understood as subject to the exception indicated above.

It will be recognized that to obtain maximum efficiency with respect to multiple feeding of workpieces to a grinding wheel, it is necessary that the work holding and work feeding devices, respectively associated with the multiple workpieces, be independently operable in order that each feeding device can cause the workpiece carried thereby to bear against the grinding wheel with a predeterminable amount of pressure being created between a given work- Where both workpieces are mounted on and carried by a'single feeding device, it is so difiicult and time consuming to adjust both of said workpieces with respect-to each other with such exactness that they will each get exactly the right amount of stock removal that this mechanism often requires more time to operate than it saves and hence isoften of no real economy or value over a machine adapted for feeding only a single workpiece. Where the tables are made for separate operations, then the pans which collect the liquid used in connection with the grinding operation are necessarily rearranged (1) so that they travel with, respectively, each workpiece feeding device or (2) the workpiece feeding devices can move independently of each other and with respect to a single liquid collecting pan.

Where the pans are arranged to move with the feeding devices, then there is motion between the pans themselves and this either requires some type of sealing apparatus between the pans or it requires acceptance of a considerable amount of spillage and leakage escaping around and between said pans onto the base of the machine or onto the floor upon which the machine is mounted. Likewise, under these circumstances where motion between the pans with respect to the frame of the machine is required, it becomes necessary to'provide some kind of sealing arrangement between the pans and the grinding wheel or the structure upon which the grinding wheel is mounted. This is extremely diflicult to carry out effectively, particularly where the grinding wheel is of an oscillatory nature. In any event, it is possible at all only at considerable additional expense and with a considerably higher maintenance cost.

Where the feeding devices are mounted to move independently of each other and with respect to a single pan,

this presents construction problems. One possible conpan large enough to cooperate with all of the feeding devices required and then by mounting each feeding device upon a single heavy post extending upwardly through the bottom of the pan, and sealing such post with respect to the bottom of the pan to prevent leakage therebetween, a highly-effective device can be produced which feed of a plurality of workpieces, will not be unduly complicated and will effectively perform the operations desired. a e a Accordingly, theprincipal objects of. the invention are:

(1) To provide work holding and feeding means for presenting a multiplicity of .workpieces to a material cutting tool;

(2) To provide work holding and feeding means, as aforesaid, which is particularly adaptable to the presenting of at least two workpieces more or less simultaneously to a single grinding Wheel;

(3) To provide work holding and feeding means, as aforesaid, wherein the respective units of said feeding means are enabled to operate independently of each other;

(4)To provide work holding'and feeding means, as

V pan, each of said posts being supported on and by indeaforesaid, which is especially adapted to an electrolytic type of grinding operation, or to any other grinding operation where there is utilized a substantial amount of liquid in contact with both the grinding wheel and the workpieces;

(5) To provide work holding and feeding means, as aforesaid, which can operate with only a single pan for the collection of such liquid as it is thrown radially from said grinding wheel and which is collected by a hood surrounding the grinding Wheel and is permitted to drip downwardly from such hood into the pan;

(6) To provide a work holding and feeding device for a multiplicityof workpieces which will be strong and sturdy and capable of feeding said workpieces with 'a high degree of precision to a material removing device, such as a grinding wheel;

(7) To provide a work holding and feeding device, as aforesaid, which will be of suflicient simplicity that it will require a minimum of maintenance;

(8) To provide a work holding and feeding device, as aforesaid, which is readily adaptable to workpieces of a range of sizes; and

(9) To provide a coolant collecting device around the work holding and feeding device which will minimize, or substantially prevent, spillage of liquid from the region of the grinding wheel to the floor or frame of the machine;

(10) To provide a Work holding and feeding device, as aforesaid, which will operate successfully, reliably and cleanly with relatively little supervision and relatively little maintenance.

Other objects and purposes of the invention will become apparent to persons acquainted with devices of the general type upon'reading the following specificat-ion and inspection of the accompanying drawings.

In the drawings: 7

Figure 1 is a front elevational fragmentary view of a grinding machine having an oscillating grinding wheel and utilizing two work holding and feeding tables;

Figure 2 is a section taken on the line II-II of Figure 1.

Figure 3 is a section taken on the Figure 2. V

Figure 4 is a top fragmentary view of the grinding wheel and tables.

General description In general, the invention contemplates providing a single pan of size sufficient to gather all liquid discharged thereinto directly from the grinding wheel and also that dripping by gravity from the hood surrounding the grinding-wheel. A plurality, such as two, tables are supported in side-by-side relationship with respect to each other and each is equipped for holding a workpiece rigidly thereon and in position for moving said workpiece into working relationship with the grinding wheel. Each of said tables is supported upon a heavy post which extends downwardly through an openingin the bottom of'said line III-III of I pendently operable mechanism for reciprocating said post a limited distance toward and away from the grinding wheel, whereby upon reciprocation of said post, the workpiece holding devices mounted, respectively, on said tables will move workpieces held thereby into grinding relationship with said grinding wheel and away therefrom. Suitable sealing means are then provided between said posts and the bottom of the pan.

Detailed description In the following description certain terminology will be used as a matter of convenience and to shorten the description. However, it should be understood that this terminology is for convenience only and is not intended to be limiting. Particularly, the terms upward and downward and derivatives thereof and words of similar import will refer to directions on the sheets of drawings accompanying this application and will also refer to directions with respect to the machine when in its normal position of operation. The terms forward and rearward together with derivatives thereof and words of similar import will refer to directions parallel with the direction of reciprocation of the work toward and away from the working zone, or conversely toward and away from the normal position occupied by the operator when operating the machine, such that the term forward" refers to the part of the machine closest to the operator and rearward refers to the part of the machine furthest from the operator, which directions are, respectively, leftwardly and rightwardly as appearing in Figure 2. The terms inward and outward and derivatives thereof and words of similar import refer to directions toward or away from the geometric center of the machine or portion of the machine referred to in connection with the use of such terminology.

Referring now to the drawings, much of the mechanism herein involved is illustrated and described in detail in application Serial No. 574,728 and application Serial No. 625,009, both assigned to the assignee of the present application. However, for convenience in reference, a brief description ofsuch mechanism will be set forth herein.

Frame structure 1 includes a table supporting base 2 and shaft supporting structure 3 (Figure 2). Said shaft supporting structure supports a shaft 4 on which is rotatably mounted a wheel backing plate 6. Any suitable grinding wheel 7 is provided and fastened in a conventional manner to the wheel backing plate 6. Means not shown are provided for rotating and oscillating the shaft 4, which means may be conventional or may be as set forth in application Serial No. 574,728.

The support base 2 carries one side 8 (Figure l) of ball race structure 9 and the other side thereof is carried by the table base 12 of the reciprocable table in a manner set forth in more detail in application Serial No. 625,009. Thus, said table base 12 is arranged for reciprocation on the raceways 9 together with corresponding raceways 10, 9a and 10a, all as set forth in detail in application Serial No. 625,009. Reciprocation of said table base 12 is effected by a power cylinder 13 (Figure 2) which is fastened at one end to said table base 12 by the pivot pin 14 and at the other end to said frame 1 by the pivot pin 16. Actuation of said power cylinder in any convenient manner (and by means not shown) effects reciprocation of said table base 12. The spring structure 15 is provided for softening or modifying the effect of the power cylinder 13.

Supported by means to be described later, there is positioned above the table base 12 a table adjustment support 17 which carries on its upper side a movable segment 18, said movable segment being so related to the adjustment support 17 that said segment'can move around a horizontal axis with respect to the support 17. A screw 19 is rotatably supported in theadjustment support 17 for actuation'by a knob-21, and'operates through a pin 22 anda yoke 23 for effecting said rotation of the segment 18 around said horizontal axis. The work supporting table 24 is mounted in any suitable manner, as by bolts, on the segment 18 for movement therewith, all as set forth and described in more detail in the above-mentioned application Serial No. 625,009. Said table 24 (Figure 4) is provided with suitable work supporting means, not shown, and-has a cut out'portion 25 into which. the wheel 7 extends in order that work may be placed in various positions on said table with respect to said wheel.

A hood 39 (Figure l) surrounds the upper part of the grinding wheel and the sides thereof and is arranged in a conventional manner with respect to the pan 2% so that liquid thrown from the grinding wheel will be caught by said hood and will drain into said pan. From said pan it is then taken in a conventional manner to the pumping system of the' grinding machine and returned in a suitable manner to the grinding area of the wheel.

The rearward edge 30 of said pan is supported in any convenient manner, such as by'welding, onto an upstanding sheet 41 which in turn ismounted at its lower edge 42 directly upon the base 1. An opening 43 is provided through said upstanding sheet for the passage of the shaft housing 5 therethrough. Said pan 28 and hood 39 in this instance are made as a single integral unit although it will be recognized that these details are matters of choice and not a part of the present invention.

All of the foregoing relates to the machine out of which has arisen the problem dealt with by the present invention and all of the parts above described are illustrated and described in more detailin said applications Serial Nos. 574,728 and 625,009.

Turning now to the particular subject matter of the present invention, attention is first directed toward Figure 1 wherein is illustrated a pair of work supporting tables here indicated as tables 24 and 24a. It will be observed that the table 24 and all parts associated therewith are duplicated in connection with table 24a and accordingly thedescription of the parts associated with the table 24 will be taken also as the parts describing the table 24a and such parts will be designated by corresponding numerals accompanied by the subscript a throughout.

The portion of the table base 12 which is located directly under the table adjustment support 17 is provided with an upstanding post 26 (Figure 2) upon which is mountedfthe adjustment support 17. A liquid collecting pan' 28 surrounds the post 26 and includes a bottom 29 and upstanding'sid'es 31. An opening 32 (Figure 3) is provided through the bottom 29 for surrounding the post 26 and said opening is provided with an upstanding flange 33 around its periphery, said flange being of height somewhat greater than the normal depth of liquid in the bottom of'said pan. The opening 32 is of lateral width (Figure 3) only suflicient to enable it readily to clear the upstanding post 26, but it is of suflicient longitudinal (Figure 2) length such that it will permit reciprocation of the post 26, and the table 24 mounted thereon, as needed to move the work toward and away from the grinding wheel.

A cap 34 is fastened to the post 26, hereby being inserted between the top of said post and the underside of the adjustment base 17 and firmly clamped therebetween It extends horizontally and has a downwardly extending skirt 36 around its entire periphery. Said cap and particularly the skirt 36 associated therewith is of sufficient width that said skirt will have an easy clearance with respect to the upstanding flange 33 (Figure 3) but is spaced sufliciently from said upstanding flange in a longitudinal direction (Figure 2) that it will permit reciprocation of said post with respect to said upstanding flange 33.

If desired, and it normally will be desirable, there is also provided a flexible cover 40, preferably of neoprene or similar material of high chemical resistance, which is also clamped between the cap 34 and the underside of the support 17. The peripheral edge of said flexible member rests against the bottom of the pan 28.

6 Operation ventional manner to move the work table 24 toward and away from the wheel 7. Simultaneously, the liquid (cutting oil or electrolyte) will be discharged in the usual manner through the pipe 20 against the wheel at a point thereon adjacent the work. Rotation of the wheel will throw such liquid radially against the hood 39 by which it will be caught and collected and returned to the pan 28. From said pan it will then be conducted in a conventional manner and by means not shown to the pumping system for recirculation back .to the discharge pipe 20. Thus, there will at all times be a pool of said liquid in the bottom of the pan 28 which pool, however, will be of a depth somewhat less than the height ofthe upstanding flange 33.

As the table base support 12 reciprocates, being permitted to do so by the opening 32 through which the post 26 extends, the downwardly extending flange 36 together with the flexible member 40 will sufficiently inhibitthe development of waves within the liquid pool, and will further provide enough of a baffle around the opening 32,

as to substantially prevent the escape of liquid from said pool over the top of said flange 33. Thus, the post 26 is permitted to extend through the bottom of the pan 23 and reciprocate therein without liquid from within said pan escaping over the top of said protective wall 33 and out through the opening 32.

It will be observed that in some instances where the rate of reciprocation is relatively slow, the flexible member 40 may be omitted without materially undesirable consequences. However, in normal operation it will be found preferable to utilize the flexible member 40 as and in the manner shown.

Therefore, each of the tables 24 and 24a together with their respectively supporting structures, can be caused to reciprocate independently of each other toward and away from the wheel '7 and thereby carry out independently of each other two grinding operations as desired but only a single liquid collecting pan 28 willbe required for the entire machine and the machine will operate without spilling any appreciable amount of the liquid utilized as a part of the grinding operation. I

With this apparatus, the'operator can load the feeding devices alternately if desired so that a grinding operation can be carried out with respect to the workpieces on one feeding device while the other feeding device is being unloaded and reloaded. Further, if desired, and where periods of different length are required for grinding different portions of the same workpiece, one type of grinding operation may be carried out on one table and another type of grinding operation may be carried out onthe other table. An example of this latter situation will be where a smaller tool surface is to be ground which may require only a few seconds and a larger tool surface is to be separately ground which may require a longer time. One feeding device and its timing mechanism may then be set to carry out one grinding operation and the other feeding device and its timing mechanism may be set to carry out the other grinding operation and the two operations will be carried out completely independently of each other. Thus, the operator has the same freedom of control over'the two grinding operations as though he were handling two separate machines but at much greater convenience due to the close proximity to each other of the two feeding devices, and the machine itself provides the economy of having only a single grinding wheel and driving mechanism for same.

Although a particular preferred embodiment of the invention has been described above in detail for illustrative purposes, it will be understood that variations or modifications of such disclosure, which lie within the scope of the appended claims, are fully contemplated.

I claim:

l. A multiple work feeding device for feeding workpieces to a material removing instrument which utilizes a liquid directed against said instrument during the material removing operation, comprising in combination: a frame and means supporting said instrument operatively on said frame; a pan arranged below said instrument and stationary with respect to said frame for collecting liquid used in association therewith during a materialtremoving operation; at least two workpiece supporting devices arranged above said pan and adjacent a working Zone of said instrument; posts extending, respectively, froms'aid workpiece supporting devices downwardly through openings in the bottom of said pan, and means mounted on said frame for supporting said. posts for reciprocable movement with respect to said pan toward and away from said instrument; and a pair of liquid seals arranged, respectively, between one of said posts and the bottom of said pan, said liquid seals permitting relative and independent movement of said posts, respectively, Within said openings and with respect to said pan; whereby each of said posts may be operated independently of the other thereof to effect correspondingly independent feeding of workpieces toward and away from said instrument and the liquid discharging from said instrument is simultaneously collected in a single, non-moving pan for return to the liquid circulation system.

2. A grinding machine comprising: a frame; a grinding wheel rotatably supported on said frame; means mounted on said frame for directing a liquid against said grinding wheel; a liquid collecting pan stationarily mounted on said frame and located below said grinding wheel for receiving liquid falling downwardly therefrom, said pan having an opening through the bottom wall thereof, said opening being elongated in a direction toward and away from said grinding wheel, a flange extending upwardly from said bottom wall of said pan around the edge of said opening; a post extending upwardly through said opening and being movable therewithin and with respect to said pan toward and away from said grinding wheel; a work supporting table mounted on the upper'end of said post above said pan for movement with said post toward and away from said grinding wheel whereby a workpiece may be moved toward and away from said grinding wheel; a cap secured to said post and located above said pan, said cap having a flange extending downwardly into proximity with the upper surface of said bottom wall of said pan and surrounding said flange on said pan, the end portions of said cap flange being spaced'apart farther than the corresponding end portions of said pan flange by a distance approximately equal to the distance said post can move within said opening toward and away from said grinding wheel so that said cap flange does not interfere with movement of said post '8 but, in conjunction with the pan flange, hinders movement of liquid into said opening; and means connected to said post below said pan for moving same toward and away from said grinding wheel.

3. A grinding machine according to claim 2 including a flexible sheet secured to said post and having a skirt surrounding said cap flange and slidably engaging the upper surface of the bottom wall of saidpan for preventing liquid from entering said opening.

4. A grinding machine according to claim 3 wherein said flexible sheet is made of neoprene.

5. A grinding machine, comprising: a frame; a grinding Wheel rotatably supported on said frame for rotation about a substantially horizontal axis; means mounted on said frame for directing a liquid against said grinding wheel; a liquid collecting pan rigidly and stationarily affixed to said frame and located below said grinding wheel for receiving liquid directed thereagainst, said pan having a pairof parallel, spaced openings through the bottom wall thereof, said openings each being elongated in a direction toward and away from said grinding wheel, said pan having a flange extending upwardly from the bottom wall thereof around the edge of each of said openings; a post extending upwardly through each of said openings, said posts'being independentlymovable within said openings and with respect to said pan toward and away from said grinding wheel; a work supporting table mounted on the upper 'end of each of said posts above said pan for movement toward and away from said grinding wheel whereby work pieces may be independently moved toward and away from said grinding wheel; a cap secured to each of said posts and located above said pin, said caps each having a flange extending downwardly into proximity with the upper surface of said bottom wall of said pan and surrounding one of said flanges on said pan, the end portions of each cap flange being spaced apart further than the corresponding end portions of its associated pan flange by a distance approximately equal to the distance its associated post can move toward and away from said grinding wheel so that said cap flange does not interfere with movement of its associated post; a resilient, flexible sheet secured to each post and having a skirt surrounding said cap flange and slidably and resiliently engaging the upper surface of said bottom wall of said pan for preventing liquid from entering its associated opening; and a pair of means supported on same frame and connected respectively to said posts for independently moving same toward and away from said grinding wheel Wiken May 1, 1945 Oliver Jan. 16, 1951

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