US3039235A

US3039235A - Cutting apparatus

Info

Publication number: US3039235A
Application number: US86117A
Authority: US
Inventors: Robert G Heinrich
Original assignee: Hamco Mach & Elect Co
Current assignee: Hamco Mach & Elect Co; Hamco Machine & Electronics Corp
Priority date: 1961-01-31
Filing date: 1961-01-31
Publication date: 1962-06-19
Anticipated expiration: 1979-06-19

Description

June 19, 1962 R. G. HEINRICH 3, 3

CUTTING APPARATUS Filed Jan. 31, 1961 4 Sheets-Sheet 1 Fig.

I43 5 57 I42 6 I46 ROBERT 6'. l'lE/NR/Ch' INVENTOR.

AGENT June 19, 1962 R. e. HElNRlCH CUTTING APPARATUS 4 Sheets-Sheet 2 Filed Jan. 31, 1961 ROBERT 6. HEl/V/P/CH INVENTOR. %X

AGE/VT June 19, 1962 R. G. HEINRICH 3,039,235

CUTTING APPARATUS Filed Jan. 31, 1961 4 Sheets-Sheet 3 AGE/VT June 19, 1962 3,039,235

R. G. HEINRICH CUTTING APPARATUS Filed Jan. 31, 1961 4 Sheets,Sheet 4 Air Exhaust ROBE/P7 6. HEl/V/P/CH IN VEN TOR.

AGE/VT United States Patent 3,039,235 CUTTING APPARATUS Robert G. Heinrich, Rochester, NY, assignor to Hamco Machine & Electronics Corp., a corporation of New York Filed Jan. 31, 1%1, Ser. No. 86,117 25 Claims. (Cl. 51-73) This invention relates to a cutting device and more particularly to a cutting device which severs thin slices from hard and brittle materials, such as silicon and germanium crystals.

In the electronic field, it is well known to use various types of crystals, such as silicon and germanium, as transistors and rectifiers. These crystals need be of very small size for such use and, consequently, it has been the prac tice to slice or cut the crystal into thin sheets or slices and, after lapping to the desired thickness and etching the surfaces to a smooth finish, cutting each slice into small pieces of the required dimensions. Crystals of the type referred to above are very hard and very brittle and for this reason, each slice or plate of a crystal is cutmuch thicker than actually required and then the slice is lapped to reduce the slice to the required thickness and then etched to obtain smooth and parallel faces. This procedure is necessary because apparatus presently available cannot cut a slice from such crystals of the required thickness and, at the same time, produce the smoothness of the surfaces and parallelism of the surfaces which is required for use of the crystal as a transistor or rectifier. In addition, the cost of such crystals is very high and the amount of waste due to cutting oversize slices makes the cost of the final piece ultimately used exceedingly expensrve.

The present invention is concerned with a cutting device which permits the thickness of the slice of the crystal to be of the exact dimension as to thickness with smooth and parallel surfaces, thereby minimizing the need for subjecting each slice to extra operations to obtain the necessary'degree of smoothness and thickness. In addition, the present cutting device is entirely automatic in its operation and permits the crystal to be of considerable length and to be out completely into thin slices without handling or adjustment of the crystal by the operator. The ability to handle a crystal of considerable length is accomplished by mounting the crystal above the horizontal annular cutting member and allowing the severed slices to fall away from the cutting member and into a receptacle. Since the crystals are of irregular cross section and can be relatively small in diameter, a single large diameter or a number of small diameter crystals with their longitudinal axes parallel can be conveniently handled by encapsulating the crystal or crystals in a plastic material. The crystal or crystals are moved against the cutting edgev of the annular member at a variable speed so as to effect at any instant a uniform material removal rate by the cutting edge. In this way, the rate of movement of the crystal is greatest as it engages and leaves the cutting edge and decreases and then increases as the cutting edge passes through the crystal, thereby eliminating cracking and/ or breaking away of a portion of the slice and providing smooth and parallel surfaces. Since the cutting time is important, the rate of removal of the crystal material is always at a maximum regardless of the position of the cutting edge with respect to the crystal, the rate of removal, of course, being consistent with the ability of the cutting member to cut properly and of the material to be cut without damage.

Besides the problem of obtaining thin slices from the crystal which have smooth and parallel surf-aces and are of the order .002.008 inch in thickness, an additional problem is encountered whereby means must be provided Patented June 1 9, 1962 within the device for receiving the slices once they have been completely severed from the crystal. Due to the brittleness of such crystals and the fact that the cutting is done under a continuous stream of a cutting liquid, the slices cannot be allowed to remain in the turbulence of the cutting liquid and the air, or to come into contact with any moving parts.

In the prior art, the cutting edge is not allowed to completely sever each slice. As the cutting edge approaches the end of its cut, the cutting element or the crystal is backed ofi so the slice is not severed completely from the crystal, the crystal then being advanced for the next cut. This arrangement presents several very important disadvantages. If the cutting edge or crystal is not backed off at the proper time and the crystal slice is completely cut off, or if not backed off at the proper time so the material holding the previously cut group of slices is not suflicient to support the cut slices, then the entire group can fall within the rotating supporting structure and be completely broken up or very badly damaged. Also, apparatus in which the cutting element is in a vertical plane limits the length of crystal which can be handled in that the length is controlled by the depth of the support for the cutting element. If a crystal has a flaw, such that as it is being cut it breaks away from its support, this single piece can cause damage to the other slices still retained on the support as it is spun and moved about within the rotating supporting structure. the amount of uncut material required to support the individual slices will vary for each material and size and the amount required for adequate support of the out slices can be determined only by expensive experimenta tion as well as a complicated set-up procedure. The uncut material also represents an appreciable percentage of waste which increases as the diameter of the crystal increases and which adds considerably to the final cost of each slice. Since the crystal is supported in a horizontal plane, only one crystal can be cut at a time regardless of its cross section size and this necessitates additional time for backing oif after each cut and indexing for the next cut.

In the present device the above disadvantages are overreceptacle being fixed and independent of the cutting member, and arranged so the cut slices arenot affected by contact with moving parts or by the turbulence of the cutting liquid or the air when they are completely severed from the crystal. It will be readily apparent from the description which follows that the present cutting device presents a unique solution to a heretofore ditfi-v cult and unsolved problem.

The primary object of the present invention is, therefore, to provide a device for cutting a crystal into thinslices of required thickness such that the slices have smooth and parallelsurfaces.

Another object of the invention is to provide a device for cutting a thin slice from a crystal in which a flat annular member is provided with a cutting edge at the inner peripherythereof and the crystal is arranged within the inner diameter of the member and moved against'said edge at a variable rate of movement.

Still another object of the invention is to provide a etfect at any instant a uniform material removal rate by said edge.

A further object of the invention is to provide a devicefor cutting a thin slice from a crystal in which a flat annular member is provided with a cutting edge at the inner Further,

3 periphery thereof, the crystal being arranged on one side of the annular member and a receptacle for receiving the cut slices being arranged on the other side of the annular member within and independent of the support for the annular member.

A still further object of the invention is to provide a device with a thin annular cutting member which is mounted so the slices cut thereby from an element can fall vertically into a receptacle supported within the structure for the cutting member and in close proximity to the cutting member or into a hollow member for directing the slices into a receptacle located below the structure for the cutting element.

Yet another object of the invention is to provide a device for cutting a thin slice from a crystal in which circuit means is provided for controlling advancement of the crystal with respect to the cutting edge of a flat annular member and movement of the crystal between two spaced positions.

And still another object of the invention is to provide a device for cutting thin slices from a crystal successively and automatically in which a flat annular member having a cutting edge at the inner periphery thereof is rotated continuously and a separate drive means moves the continuously rotating crystal between two positions for severing each slice, the movement of the crystal in one direction being at a variable rate of movement and in the other direction at a uniform rate of movement.

These and other objects and advantages will be apparent to those skilled in the art by the following description of a preferred embodiment of the invention and reference should be made to the accompanying drawings wherein like reference numerals designate like parts and wherein:

FIG. 1 is a vertical section through the device showing the relation of the various parts to each other;

FIG. 2 is a detail plan view of the annular cutting member;

FIG. 3 is a plan view of the device shown in FIG. 1;

FIG. 4 is an end elevation as viewed from the right of FIG. 1;

FIG. 5 is a partial vertical section through the head for supporting the element in which the crystal is stationy;

FIG. 6 is a partial end view of the mechanism for controlling the rate of movement of the crystal;

FIG. 7 is a diagrammatic view showing the relation of the crystal to the cutting edge as it is moved from left to right whereby at any instance equal volumes of the crystal are removed by the cutting edge; and

FIG. 8 is a schematic view of the control circuit and the pneumatic system for advancing the crystal prior to each cutting operation.

With reference particularly to FIGS. 1 and 2, the cutting member 10 is a flat, annular metal plate having an aperture 11. A cutting abrasive, such as diamond dust, is embedded or bonded to the edge of aperture 11 and to the surfaces of plate 10 adjacent said aperture, as shown by shading with dots in FIG. 2.. This portion, designated by 12, is the effective cutting edge of plate 10'. Plate 10 can be made of material such as beryllium copper, Phosphor bronze or stainless steel, is of a thickness of approximately .002-.0()6 inch and has an outer diameter of 7% inches and an inner diameter of 3 inches, these dimensions being provided merely as an example.

The device is mounted on a bed plate 13 which is provided with an aperture 14, sleeve 15 being secured to plate 13 by bolts (not shown) and extending both above and below said plate to provide a bearing forthe means for supporting plate 10. The means for supporting annular plate 10 comprises a hollow sleeve 16 which is rotatably supported in sleeve 15 by spaced bearings 17 in a well-known manner, the hollow sleeve having a pulley 18 fixed at the lower end and a cup-shaped member 19 fixed thereto at the upper end and on which annular plate 16 is secured in a manner about to be described.

The cup-shaped member 19 includes a plate 24) which is joined to sleeve 16 to provide a unitary member designated by 22. Member 19 is provided with a flange 23 which carries a flanged ring 24, said ring being secured to flange 23 by screws 25 and being provided with an annular groove 26. The annular plate 10 is centered with respect to the axis of member 22 and held in this position by retaining ring 27 which threadably engages ring 24. A third ring 28 is provided with an annular proturberance 29 which aligns with the groove 26 in ring 24 when ring 28 is threaded into engagement with retaining ring 27, as shown in FIG. 1. As ring 28 is moved axially toward plate 10, the proturberance 29 engages plate 10 and forces it into groove 26, thereby tensioning plate 10 and securely fixing it in position. A motor 151, shown diagrammatically in FIG. 8, is connected to pulley 18 by belt 30 and rotates member 22 and annular plate 10 through a vari-drive system at speeds variable between LOGO-10,000 r.p.m.

The arrangement of

rings

24, 27 and 28 is such that they very readily lend themselves to providing an assembly with the annular plate 10 whereby the plate 10 can be radially tensioned before mounting on flange 23. For example, plate It is properly aligned with ring 24 and ring 27 is then threadably engaged and tightened on ring 24 to securely clamp said plate therebetween. Once the annular plate 10 is clamped in position, ring 28 is then threaded into ring 27 and as it is moved toward ring 24, the annular protuberance 29 engages and then forces the annular plate 10 into the annular recess 26 in ring 24, thereby radially tensioning said annular plate. This unit comprising rings 24, 27 and 28 with the annular plate 10 properly aligned and tensioned can then be merely placed on flange 23 and secured in position by screws 25. In this way, the tensioning of annular plate 10 can be accurately accomplished independent of the supporting member therefor and under controlled conditions which is not possible in the prior art structures because the supporting member for the plate 10 is essential to the tensioning of said plate.

Since the means for receiving the severed slices of crystal 31 is arranged in conjunction with the means for supporting the annular plate 18', it will now be described. As described above, sleeve 16 is hollow and rod 32 is arranged within sleeve 16 and mounted in fixed relation on plate 33 which is located below pulley 18. At the upper end of rod 32, a receptacle 34 is mounted thereon by the cylindrical extension 35 which engages a corresponding hole 36 provided in the end of said rod. Receptacle 34 comprises a cylindrical portion 37 and a flange 38 diverging therefrom toward annular plate 10. As member 22 rotates continuously, the receptacle 34 is stationary and its flange 38 is so positioned immediately adjacent and with respect to plate 10 that the cut slice has a minimum distance to fall and then slides into the portion 37. As shown in FIG. 1, a separate container 39 can be placed inside portion 37 and can be removed through the aperture 11 of plate 10, thereby eliminating the need for removing plate 10 after a crystal has been completely cut into slices. Rod 32 can also be hollow, in which case container 39 would be located below plate 33 and the slices would then be carried by water or the cutting liquid through the tubular rod 32' and deposited in the container, I

see FIG. 5.

Since crystals, at present, are irregular in cross section, the crystal 3! is preferably encapsulated in a plastic material to provide an element, which can be easily handled, the plastic material being removed after the element has been cut into slices of the required thickness. In the present instance, the crystal 31 is encapsulated in cylindrical form for insertion into collet 41 which retains said crystal in an upright position and normal to the plane of annular plate 10.

The means for supporting crystal 31 in relation to plate 10 comprises a pedestal 42 which is mounted on plate 13, a movable table 43 which is slidably mounted on pedestal 42 in a manner described hereinafter, and a carrier 44 which is fixed to table 43 and movable there with. Pedestal 42 is provided with a gibbed cross piece 45 which, in turn, is provided with a central opening 46, the ends 47 and 48 of cross piece having sleeve bearings 49 inserted therein for rotatably supporting screw 50. The right hand end of screw 50 extends beyond the face of pedestal 42 and has a gear 51 keyed thereto. Gear 51, in turn, engages gear 52 which is carried by the stub shaft 53 which also has fixed thereto a sprocket 54. The cross piece 45 is provided along the top edge thereof with ways which engage complementary ways 55 on movable table 43 in a manner well known in the machine art. The movable table 43 is provided with a central opening 56 in which is inserted and secured a nut 57 which engages screw'50. As sprocket 54 is rotated in a manner to be described hereinafter, gear 52 rotates gear 51 which, in turn, rotates screw 50, thereby imparting movement by nut 57 to table 43, the direction of movement of table 43 being dependent on the direction of rotation of screw 50.

Carrier 44 comprises a plate 60 which is secured to movable table 43 by screws or the like and carries a bearing portion 61. In the embodiment disclosed in FIG. 1, a small motor 62 is mounted on plate 60 and drives a pulley 63 fixed to its shaft. This pulley is connected by belt 64 to a pulley 65 which is integral with sleeve 66. Sleeve 66 is rotatably mounted in portion 61 by

bearings

67 and 68 and at the lower end thereof is provided with a tapered shoulder 69. Collet 41 is arranged within sleeve 66 and at its lower end is provided with a tapered flare 70 which engages the tapered shoulder 69 of sleeve 66. The encapsulated crystal 31 is carried by collet 41 and retained thereby in relation to annular plate 10. Collet 41 extends beyond pulley 65 and has two threaded portions for receiving ring 71 and ring 72, said rings being spaced from each other with a Belleville spring 73 arranged between ring 71 and pulley 65. Ring 72 forms a support for a hydraulic ram assembly, indicated generally by 74, which serves as the means for advancing crystal 31 toward annular plate 10. Ram assembly 74 is a commercially available article which is mounted on ring 72 by collar 75 threaded thereto, the ram assembly being mounted on thrust bearings 76 and radial bearing 77 to permit crystal 31, collet 41, pulley 65, sleeve 66, ring 71, ring 72, spring 73 and collar 75 to be rotated by motor 62 ,as said ram assembly remains fixed. The ram assembly 74 is provided with a piston 78 which engages a thrust bearing 21 arranged between the top surface of the encapsulated crystal 31 and said piston.

The means for rotating crystal 31 independently of the annular member comprises motor 62 which is connected to collet 41 via belt 64. Crystal 31 is preferably rotated at a speed less than 100 rpm. and can be rotated in a direction with or against annular member 10. If crystal 31 is rotated, then a crystal can be out which will be twice the maximum diameter of a crystal which is not rotated. In other words, the same size cutting member will then cut a much larger diameter crystal. The movement of crystal 31 against edge 12 will, however, still be such as to effect a uniform material removal rate.

When the hydraulic rain assembly 74 is actuated, piston 78 moves the encapsulated crystal downwardly and toward the annular plate 10. If this movement is opposed for any reason, collet 41 and the associated parts will then move with the crystal tending to compress spring 73 because sleeve 66 is fixed. As the tapered

portions

69 and 70 are moved relative to each other, the collet 41 relaxes its grip on crystal 31 allowing it to move through collet 41 but spring 73 maintains sufficient force against said crystal to minimize any back feeding due to the collet action. The action of piston 78 for advancing crystal 31 is controlled by an arm 80 arranged within receptacle 34 and the inner aperture of annular plate 10, as shown in FIG. 1. Arm 80 is secured to a post 81 which is slidably mounted in the bracket 82 fixed to pedestal 42, see FIGS. 3 and 4. Bracket 82 carries a microswitch 83 which is actuated by the adjustable stud 84 in a manner to be described hereinafter. Both post 81 and stud 34 are integrally mounted on plate 85, a spring 86 being arranged about post 81 between bracket 82 and plate 85. Stud 84 is moved up or down with respect to plate 85 so as to locate arm 80 with respect to annular plate 10. Arm 80 is moved from an upper posi tion in which it is maintained by spring 86 to a lower position in which stud 84 aetuates switch 83 by crystal 31 as it is advanced by piston 78. In the lower position, the action of ram assembly 74 is arrested when the crystal 31 has been advanced sufficiently to permit a slice of the desired thickness to be cut including allowance for the thickness of the cutting edge 12. It is for this reason that stud 84 is threadably mounted in plate 85, thereby permitting the lower position of arm 80 to be adjusted for the thickness of the plate 10 and the required thickness of the slice to be cut with respect to the actuating position of switch 83.

- In FIG. 5, an embodiment is shown in which the crystal 31 is not rotated but is held stationary as carrier 44 is moved with table 43. In this arrangement, sleeve 66 fits snugly in bearing portion 90, said sleeve being provided with a tapered end or shoulder 69, as in FIG. 1. Collet 41 is also similar in that it carries a collar 91 with a Belleville spring 92 arranged between collar 91 and the end of sleeve 66. Plate 93 on the end of collet 41 carries ram assembly 74, said assembly being hinged to plate 93 at 94 so it can be swung out of position to permit a crystal to be inserted into collet 41 from the top, the assembly then being returned and clamped in an operative position in any well-known manner.

The cutting of crystal 31 is accomplished with a continuous stream of water or other cutting liquid directed against the cutting edge from both the top and bottom. This is shown partially in FIG. 3 by pipe 95 which is connected to a pump (not shown) in a liquid circulating system. With reference to FIG. 1, the liquid drains into receptacle 34 and causes the slices as they are cut to slowly sink to the bottom and into container 39. In this way, the thin slices are prevented from being cracked or broken. The liquid overflows the edges of flange 38 and drains into the cup-shaped member 19 which is provided with a plurality of openings 96. Since member 22 is rotated continuously, the liquid is thrown off through openings 96 into the chamber 97 formed by casing 98. A suitable drain is provided to return the liquid to the rese voir of the system. A removable cover 99 is provided with an irregular opening 100 of a size sufiiciently large to permit movement of crystal 31 and clearance for post 81 and arm 80.

The means for controlling movement of table 43 and crystal 31 comprises a variable speed drive, such as a commercially available unit known by the trade name Zero-Max and designated by the numeral in FIG. 6, and the control elements associated therewith and about to be described. The drive unit 110 is provided with an output shaft 111 and a control shaft 112. Sprocket 113 is secured to shaft 111 and is connected by chain 114 to sprocket 54 on stub shaft 53-, see FIG. 1. Plate 115 is secured to shaft 112 and carries a pin 116 which is maintained against stop 117 by spring 118 when the crystal is in its first position, that is, within the inner diameter of annular plate 19, this position of pin 116 being the maximum speed setting position for drive unit 110. The periphery of plate 115 is provided with a notch 119 which is engaged by the nose of pawl 120 pivotally mounted in slot 121 in ring 122. The ring 122 is freely movable about the periphery of plate 115 and carries an arm 123 on which a cam follower 124 is freely and rotatably mounted on the pin 125. A second ring 126 is mounted on ring 122 and provided with a slot 127 through which arm 123 extends and a slot 128 for engaging pawl 120 for a purpose to be described hereinafter. Ring 126 is connected by cable 129 to the armature of solenoid 130 and by spring 131 to arm 123 which is held against cam 132 by spring 133 having its other end fixed to the machine frame. Cam 132 is freely rotatable on stub shaft 134 which is mounted in pillow block 135 secured to the machine frame. A pulley 136 is integral with cam 132 and cable 137 is wrapped about said pulley, one end of the cable being connected to spring 138 which is secured to the machine frame and the other end being secured to cross piece 45 after passing upward through the aperture 139 in plate 13, around pulley 140 on cross piece 45, around pulley 141 on cross piece 45 and around pulley 142 on movable table 43, as shown by the dotted lines in FIG. 1.

At this point, without discussing their function, it should be noted that

microswitches

143 and 144 are mounted in spaced relation on cross piece 45 and movable table 43 carries two spaced actuating

members

145 and 146 which actuate the respective switches as described hereinafter. These

switches

143 and 144 together with switch 83 comprise the circuit means for controlling the sequence of operation.

The sequence of operation will be best understood if the function of the control means for driving unit 110 is first described. Assuming annular plate is rotating and drive unit 110 has been energized without considering advancement of crystal 31, sprocket 113 will be rotated and through chain 114, sprocket 54, gear 52, and gear 51, screw 51) will be rotated to drive nut 57 to the right, thereby imparting movement to movable table 43 and carrier 44. This means that crystal 31, motor 62 and ram assembly 74 are also moved since all of these elements and their associated parts are mounted on said carrier and movable table. As noted above, pin 116 is against stop 117 and this is then in the maximum speed position of drive unit 1111. As table 43 moves to the right, pulley 142 is carried therewith. This movement of pulley 142 to the right increases the distance between

pulleys

142 and 141, thereby expanding spring 138 due to the pull on cable 137, the amount of movement being doubled due to the relation of

pulleys

141 and 142. Since pulley 136 and cam 132 are integral and cable 137 is wrapped about said pulley, the movement of pulley 142 causes pulley 136 and cam 132 to rotate in a clockwise direction. As this occurs, arm 123 and ring 122 are rotated in the same direction, ring 126 being carried with ring 122 due to the interconnection by spring 131. As the edge 147 of slot 128 leaves the tail of pawl 120, the nose of said pawl prepares to engage the notch 119 so plate 115 and shaft 112 are joined to

rings

122 and 126, thereby changing the speed of output shaft 111 as cam 132 is rotated by the movement of table 43. As described more completely hereinafter, when switch 144 is actuated by member 146, crystal 31 will be over annular plate 10 and a thin slice therefrom will have been cut by edge 12 and at this time solenoids 1311 and 185 will be energized. As the armature of solenoid 130 is drawn to the right, ring 126 is moved counterclockwise against the action or spring 131, arm 123 and ring 122 being held by cam 132. This rotation of ring 126 results in the edge 147 of slot 128 engaging the tail of pawl 12% and pivoting it about to remove its nose from notch 119, thereby permitting spring 118 to return pin 116 against stop 117 and increasing the speed. The movement of plate 115 and shaft 112 in the counterclockwise direction causes the drive unit 110 to return to its initial high speed. Sprocket 113 through drive unit 1111 is then driven in the opposite direction to move table 43 to the left to return to its initial position where it is arrested when member 145 actuates switch 143. Table 43, crystal 31 and the other associated elements are therefore moved to the right at a continually changing speed and to the left at a uniformly high speed.

Cam 132 is designed so its actuating surface varies the rate of movement of crystal 31 as it is moved against edge 12 of annular plate 18. In FIG. 7 this is shown pictorially. When crystal 31 is within the inner diameter 11 of plate 10, having been advanced against arm 80, its initial movement to the right is at the maximum 8 speed of drive unit as reduced by the elements con necting shaft 111 to table 43. As table 43 continues to move to the right, cam 132' causes the speed to con tinually change, at first reducing the rate of movement of table 43 and, as the edge 11 cuts through and ap proaches the other side of crystal 31, increasing the rate of movement. In other words, the rate or" movement of crystal 31 at the time it first engages the edge 12 and at the time it leaves the edge will be approximately the same. However, as crystal 31 is moved against edge 12, the rate of movement will be constantly changing and is such that at any instant, edge 12 will always be removing an equal volume of crystal 31 to efiect removal of a thin slice. The actuating surface of earn 132 therefore ettects a uniform material removal rate while edge 12 is cutting crystal 31.

Cycle of Operation A cycle of operation will now be described to fully present the complete cycle for removing or cutting a thin slice from the crystal 31, reference being made particularly to P16. 8 for the circuit means for controlling such cycle. The main switch 150 is first closed to energize motor 151 which is utilized to drive sleeve 16 via belt 30 and pulley 18. Motor 151 is of a constant speed type driving the unit 22 through a variable pitch pulley system and is adjusted by means of an indicating tachometer, not shown, to the desired speed for rotating annular plate 10. With the main switch 150 closed, line 152 supplies current to the contacts of

switches

153, 154 and .155 by line 149 and to motor 62 via switch 148, when closed, by line 156 to switch 157, by line 158 to normally open switch 83 and by line 182 to switch 144. Ram assembly 74 is then removed by backing ofi collar 75, or by releasing the clamp and swinging the assembly about hinge 94 if the embodiment in FIG. 4 is being used, to permit insertion of the crystal 31 into collect 41 through the upper end. The assembly 74 and piston 78 a are then relocated and locked in position. Switch 148 is then closed to energize motor 62 for rotating crystal 31. Switch 157 is then moved to On position thereby connecting the solenoid air valve 159 to ground by line 162, which opens said valve to feed air to the hydraulic booster 168 through line 161 to chamber 163 to create a high pressure in chamber 164. Oil is supplied to chamber 164 by the reservoir 165 connected thereto by line 166. Piston 167 moves this high pressure oil through line 168 and the normally open valve 169 and flow valve 170 in said line to the upper end of piston 78 in ram assembly 74. Piston 78 is moved downward against crystal 31 and when it engages said crystal moves it through. collet 41. Cushion oil in the lower chamber of assembly 74 is caused to flow through line 171 via flow valve 172 and normally open solenoid valve 173 to storage reservoir 174.

As crystal 31 moves downward, it eventually contacts arm 88 and moves it therewith until stud 84 engages and closes switch 83 which, in turn, by

lines

175, 187 and 188 cause energization of

switches

153 and 154. Switch 153 energizes

solenoid valves

169 and 173 via lines 176 and 177 to close said valves, thereby stopping movement of crystal 31 which is then held by collet 41. At this point, the lower end of crystal 31 is within the inner diameter of annular plate 10 and spaced from the cutting edge 12. Since in this position of crystal 31, member 145 is holding switch 143 open, switch 153 is not held in by switch 143 until table 43 starts to move. Switch 154 energizes drive unit 110 via

lines

178 and 179, thereby rotating sprocket 113 and moving table 43, as described in detail above.

As table 43 and the parts associated therewith move to the right, actuating member 145 is moved away from switch 143 and it returns to its normally closed position to hold in

switches

154 and 155 via

lines

152, 149, 180, 181, 187, and 188, because as soon as crystal 31 leaves arm 80, switch 83, which had been holding in

switches

154 and 155, returns to its normally open position. Table 43 continues to move to the right and crystal 31 is moved against edge 12 at a variable rate of movement, as described above. After the slice has been cut from the crystal, the crystal is in a position spaced from its initial position and over the top surface of annular plate 10. When in this second position, actuating member 146 engages switch 144 to close it and by

lines

182 and 183 energizes switch 155. Switch 155 then energizes solenoid 131} via line 184 and solenoid 185 via line 186, said switch being held in via line 152, line 182, switch 144 and line 183. Solenoid 130 returns ring 126 to its initial position and holds it in this position until cam 132 has returned arm 123 to its initial position, as shown in FIG. 6 and described above. During this interval, pawl 120 is held out of notch 119 by ring 126 after being moved by the edge 147 of slot 128 as described above. Solenoid 185 is part of the drive unit 110 and causes the direction of rotation thereof to be reversed. Drive unit 110 therefore causes sprocket 113 to be rotated in the opposite direction at maximum speed, thereby moving table 43 to the left. 1

With movement of table 43 to the left, actuating member 146 is moved away from switch 144 so it opens and switch 155 is held in via line 152, line 149, switch 153, line 1811, switch 143, line 181, line 187, line 188, line 147 and line 183. Table 43 continues to move to the left until actuating member 145 opens switch 143. With the opening of switch 143 which provides for the holding in of

switches

153, 154 and 155, all of these switches return to their normally open positions, thereby causing drive unit 110 to stop, de-energizing

solenoids

130 and 185 to release ring 126 and to change the direction of drive so unit 118 will move table 43 to the right with the next cycle of operation, and opening

valves

169 and 173 to permit advancement of crystal 31 by piston 78 toward arm 80 which, when moved sufficiently, causes stud 84 to again close switch 83 and thereby commence another cycle. Booster 168 and reservoir 174 exhaust through

lines

190 and 191 connected to air valve 159 and then through line 194, when switch 157 is in the On position. By merely moving switch 157 to the REV position, valve 159 is energized via

lines

152, 156 and 192 and it thereby switches the high pressure air from line 193 via valve 159 to line 191. When the high pressure air is introduced into reservoir 174, the oil is forced to the other side of ram assembly 74 via line 171, solenoid valve 173 and flow valve 172, thereby returning piston 78 to its uppermost position. Oil on the top side of ram assembly 74 is then forced through line 168, valve 178 and solenoid valve 169 into chamber 164 and, thence, into reservoir 165 via line 166. High pressure air is also supplied to booster 160 via line 190 to return its piston to the uppermost position, the air in chamber 163 being exhausted via line 161 and valve 159 to line 194. This procedure is necessary, by way of example, each time the apparatus has been in operation for about four continuous hours.

From the above description of the apparatu and the cycle of operation, it should be evident that the structure provided for receiving the thin slices of the crystal is a unique arrangement in that the slices are not subjected to damage or breakage due to the turbulence of the air and the cutting liquid within the cup-shaped member which supports the annular cutting member. Further, the movement of the crystal is controlled during the cutting portion of the cycle so as to effect a uniform material removal rate. While various modifications of the disclosed embodiment of my invention may be apparent to those skilled in the art, upon reading the above description, the invention is not to be limited to the precise de-. tails disclosed but is of a scope as defined by the appended claims.

Having now particularly described my invention, what 10 v I desire to secure by Letters Patent of the United States and what I claim is:

1. In a device having a flat annular member provided with an edge at the inner periphery thereof for cutting an element into thin slices, the combination comprising means for supporting said annular member in a plane normal to the axis of the element, a drive means operatively connected to said supporting means for continuously driving said annular member, a movable member for supporting said element in relation to said annular member, a second drive means operatively connected to said movable member for moving said movable member and said element between a first position in which said element is arranged within the inner diameter of said annular member and a second position in which said element is arranged in relation to one surface of said annular member between said inner diameter and the outer periphery of said annular member, a slice of said element being cut by said edge as said element is moved from said first position to said second position, means arranged within and independent of said supporting means for said annular member for receiving the cut slices of said element, and means operatively connected to said movable member and to said second drive means for controlling the movement of said element as it is moved from said first position to said second position so as to effect a uniform material removal rate.

2. A device in accordance with claim 1 wherein said supporting means for said annular member comprises a hollow shaft having a flanged cup-shaped member at one end thereof to which said annular member is secured.

3. A device in accordance with claim 1 including means operatively connected to said movable supporting member for continuously rotating said element.

4. A device in accordance with claim 2 wherein said hollow shaft is arranged vertically and below said annular member.

5. A device in accordance with claim 2 wherein said receiving means comprises a receptacle mounted Within said cup-shaped member, said receptacle being supported below said annular member and in a vertical fixed relation to said annular member by a member extending through said hollow shaft.

6. A device in accordance with claim 5 wherein said receptacle is supported by a tubular member within said hollow shaft, said tubular member directing said slices downwardly into a container arranged below said receptacle.

7. A device in accordance with claim 5 wherein said annular member is arranged horizontally between said member for supporting said element and said receptacle.

8. A device in accordance with claim 1 wherein said controlling means comprises a cam member operatively connected to said movable member and rotatable upon movement thereof from said first position to said second position so as to change the speed of said second drive means whereby a constant volume of said element is removed by said annular member at any instant during the interval said element is moved from said first position to said second position.

9. In a device having a flat annular member provided with an edge at the inner periphery thereof for cutting an element into thin slices, the combination comprising means for supporting said annular member in a horizontal plane and normal to the axis of the element, a drive means operatively connected to said supporting means for continuouslyv driving said annular member, a movable member for supporting said element in relation to said annular member, a second drive means operatively connected to said movable member for moving said movable member and said element between a first position in which said element is arranged Within the inner diameter of said annular member and a second position in which said element is arranged in relation to the top surface of said annular member between said inner diameter and Iii the outer periphery of said annular member, a slice of said element being cut by said edge as said element is moved from said first position to said second position, means arranged within and independent of said supporting means for said annular member for receiving the cut slices of said element, means operatively connected to said movable member and to said second drive means for controlling the movement of said element as it is moved from said first position to said second position so as to effect a uniform material removal rate, and circuit means including switch means actuated by said element and said movable member for establishing a sequence of operation to control movement of said element between said first and second positions.

10. A device in accordance with claim 9 wherein said circuit means includes a first switch actuated by said movable member when in said first position and a second switch actuated by said movable member when in said sec-nd position for controlling the direction of drive of second drive means.

11. In a device having a fiat annular member provided with an edge at the inner periphery thereof for cutting an element into thin slices, the combination comprising means for supporting said annular member in a horizontal plane and normal to the axis of the element, a drive means operatively connected to said supporting means for continuously driving said annular member, a movable member for supporting said element in relation to said annular member, a second drive means operatively connected to said movable member for moving said movable member and said element between a first position in which said element is arranged Within the inner diameter of said annular member and a second position in which said element is arranged in relation to the top surface of said annular member between said inner diameter and the outer periphery of said annular member, a slice of said element being cut by said edge as said element is moved from said first position to said second position, means arranged Within and independent of said supporting means for said annular member for receiving the cut slices of said element, means operatively connected to said movable member and to said second drive means for controlling the movement of said element as it is moved from said first position to said second position so as to effect a uniform material removal rate, means engaging said element for advancing a predetermined amount of said element beyond the plane of said annular member to establish the thickness of the slice, means arranged'in the path of advancement of said element for determining the predetermined amount of advancement of said element, and circuit means for establishing a sequence of operation to control advancement of said element and movement of said element between said first and second positions.

12. A device in accordance with claim 11, including means arranged on and movable with said supporting means for continuously rotating said element during movement thereof between said positions.

13. A device in accordance with claim 11 wherein said advancing means comprises a hydraulically actuated piston.

'14. A device in accordance with claim 11 wherein said circuit means includes a first switch actuated by said movable member, upon movement into said first position, for initiating advancement of said element, a second switch actuated by said element, upon movement of said element into engagement with said determining means, for arresting advancement of said element and initiating said second drive means for moving said element from said first position to said second position, and a third switch actuated by said movable member, upon movement into said second position, for reversing said second drive means to move said movable member from said second position to said first position.

15. In a device having a flat annular member provided with an edge at the inner periphery thereof for cutting an element into thin slices, the combination comprising drive means operatively connected to said annular member for continuously rotating said annular member, means arranged with respect to said annular member for movably supporting said element in relation to said edge of the annular member, means operatively connected to said supporting means for moving said supporting means and said element between a first position in which said element is arranged Within the inner diameter of said annular member and a second position in which said element is arranged in relation to one surface of said annular member, a slice of said element being cut by said edge as said element is moved from said first position to said second position, means carried by said supporting means and engaging said element for advancing said element toward said annular member upon movement of said supporting means and said element from said second position into said first position, means operatively connected to said supporting means and said moving means for controlling the movement of said element as it is moved from said first position to said second position so as to effect auniform material removal rate, and circuit means for establishing a sequence of operation to control advancement of said element and movement of said element between said first and second positions.

16. A device in accordance with claim 15 wherein movement of said element toward said annular member is controlled by a member arranged on said supporting means and in the path of advancement of said element, said member being fixed in relation to said annular member in accordance with the desired thickness of the slice of said element to be cut.

17. A device in accordance with claim 15 wherein said means for moving said supporting means comprises a variable speed drive which is controlled as to speed by a cam member connected to said supporting means and rotatable upon movement thereof from said first position to said second position for varying the speed of said drive to effect a uniform material removal rate and which moves said supporting means from said second position to said first position at a constant and uniform speed.

18. A device in accordance with claim 15 wherein said means for advancing said element comprises a hydraulically operated piston arranged on said supporting means and engaging said element, said piston being actuated to advance said element upon movement of said element into said first position.

19. A device in accordance with claim 15 wherein said circuit means includes a first switch actuated by said supporting means, upon movement into said first position, for initiating advancement of said element, a second switch actuated by said element, upon a predetermined movement of said element toward said annular member, for arresting advancement of said element and initiating movement of said supporting means for said element from said first position to said second position, and a third switch actuated by said supporting means, upon movement into said second position, for reversing the direction of movement of said moving means to return said supporting means and said element to said first position.

20. A mounting device for an annular saw provided at its inner periphery with a cutting edge comprising a first ring for engaging and supporting said saw at the outer periphery thereof and in alignment therewith, a second ring threadably engaging said first ring for clampng said saw therebetween, a third ring threadably engagmg said second ring, and means carried by said first and third rings for coacting, when said rings are in assembled relation, to radially tension said annular saw.

21. A device in accordance with claim 20 wherein said means includes an annular recess in one of said rings and an annular protuberance on the other of said rings for cooperatively engaging the portion of the saw therebetween to radially tension said saw as said third ring is moved axially toward said first ring.

22. A device in accordance with claim 20 wherein each of said first and second rings include an inwardly extending flange, said first ring includes an annular recess arranged between the inner diameter of its flange and the inner diameter of said flange on the second ring, and said third ring includes an annular protuberance cooperating with the annular recess of said first ring to radially tension said saw as said third ring is moved axially toward said first ring.

23. In a device having a flat annular member provided with an edge at the inner periphery thereof for cutting a thin slice from an element, the combination comprising drive means operatively connected to said annular member for continuously rotating said annular member, means for supporting said element on one side of and normal to the plane of said annular member, a second drive means independent of said first drive means and operatively connected to said element 'for moving said element in a straight path parallel to the plane of said annular member from a first position in which said element is arranged within the inner diameter of said annular member to a position in which said element is arranged in spaced relation to said first position and adjacent one of the surfaces of said annular member, the speed of said second drive means being continuously varied in accordance with the relation of said edge with respect to said element, and means operatively connected to said second drive means for controlling movement of said supporting means to effect removal by said edge of equal volumes of said element at any instant during movement of said element from said first position to said second position.

24. A device in accordance with claim 23 wherein said controlling means comprises a cam operatively connected to said supporting means and said second drive means, said cam being rotated by the movement of said supporting means to effect changes in speed of said second drive means to provide a uniform material removal rate.

25. A device in accordance with claim 23 and including means arranged on and movable with said supporting means for continuously rotating said element.

References Cited in the fileof this patent UNITED STATES PATENTS 2,440,464 Ewaldson Apr. 27, 1948 2,460,386 Hillquist Feb. 1, 1949 2,713,339 Sayers July 19, 1955