US3662733A

US3662733A - Annular cutting apparatus with work removal means

Info

Publication number: US3662733A
Application number: US31645A
Authority: US
Inventors: Isamu Okamoto
Original assignee: YOJI HATTORI
Current assignee: YOJI HATTORI
Priority date: 1969-10-12
Filing date: 1970-04-24
Publication date: 1972-05-16
Anticipated expiration: 1989-05-16

Abstract

A cutting device includes an annular cutting member for cutting a crystal into slices which have smooth and parallel surfaces. The crystal is supported by a crystal holder in a rotatable head and is cut into slices which are aligned with the crystal axis with a high degree of precision. The cut slices are safely and readily removed by a takeout means which is provided beneath the annular cutting member.

Description

United States Patent 51 May 16,1972

Okamoto [54] ANNULAR CUTTING APPARATUS WITH WORK REMOVAL MEANS [72] inventor: lsamu Okamoto, Yokohama, Japan {73] Assignee: Yoji Hattori, Tokyo, Japan [22] Filed: Apr. 24, 1970 [21] Appl. No.: 31,645

[30] Foreign Application Priority Data Oct. 12, 1969 Japan ..44/81375 Oct. 12,1969 Japan .....44/8l374 Oct. 12, 1969 Japan ..A4/96933 [52] us. Cl ..12sns,s1/73 [5 l] Int. Cl ..B28d1/04 [58] Field oiSearch ..51/73; 125/13-15 [56] References Cited UNITED STATES PATENTS 3,039,235 6/1962 Heinrich....................................51/73 3,168,893 2/1965 Johnson 125/13 3,154,990 11/1964 Woods ....l25/l3 X 3,232,009 2/1966 Awender ..5 1/73 3,577,861 5/1971 Bender Primary ExaminerHarold D. Whitehead Attorney-Oblon, Fisher & Spivak [57] ABSTRACT 8 Claims, 15 Drawing figures PATENTED 1 6 I972 EIHLEI 1 OF 8 INVEH'IOR ISRMU OKHMOTO ATTORNEYS mvnmon ISEHU QKAMOTO ATTORNEYS PATENTEnm 16 I972

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SILFEI 8 GF 8 INVENTOR ISAM u ozn Moro n 06w. Pm. a spam ATTORNEYS BACKGROUND OF THE INVENTION This invention relates generally to a cutting device and more particularly to a cutting device which severs slices from materials, such for example as silicon crystals, germanium crystals, and the like.

Silicon crystals. germanium crystals, and like crystalline materials are generally used in the production of semi-conductor elements, such for example as transistors. diodes. and like devices. In the manufacturing of such elements, it is necessary to cut the crystals into slices which are subsequently diced into small chips. In the process for manufacturing the semi-conductor elements from crystals, the cutting of the crystals into slices is very important. The cut slices have to be produced with smooth parallel surfaces and each slice has to be of consistent thickness. Moreover, the cut slices have to be precisely aligned with the crystal axis. Because the physical properties of the crystals are such that they are hard and brittle. they have to be handled with special care. In particular, even a minute force will break the slices such that extreme care must be taken in cutting and handling.

Former cutting devices have adopted several methods of attempting to overcome the problems of slicing and handling crystals with varying degrees of success. For the purpose of adjusting the crystal axis, a holder has been utilized which holds the crystal along the longitudinal direction and includes some means for inclining the crystal. However. as the reading of the angle of inclination is obtained by a conventional scale which is attached along the line of an arc. the alligning precision is fairly low. In other words, it is impossible to adjust the holder with a high degree of accuracy and generally is limited to an accuracy of plus or minus 30 minutes. The annular cutting member is generally attached to a support by inflicting tension upon the cutting member itself such that it tends to transform into a dish-shape. n former cutting devices an actuating table is provided which supports the crystal holder for reciprocating completely in a horizontal plane. Therefore, the crystal which is held by the crystal holder is not necessarily moved parallel to the plane of the annular cutting member. This movement will generally create a cutting mark on the surface of the slices.

For the purpose of making each slice of consistent thickness, the crystal must be intermittently fed to the annular cutting member. On former cutting devices the crystal is advanced outwardly by an oil pressure ram which has the stroke thereof controlled by a stopper. The advancing mechanism utilizing an oil pressure ram can only operate with low precision, because dust will generally enter into the device over a period of time creating dimensional errors such that slices of equal quality will not be produced.

A receptacle is generally positioned subjacent the annular cutting member in the prior art devices for removing the cut slices which must subsequently be picked up through an aperture in the annular cutting member by a pincette or like device.

As is clear from the above description relating to the former cutting devices, such devices have various defects. The subject invention solves the above mentioned defects.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a device for cutting a crystal into slices of desired thickness having smooth and parallel surfaces.

Another object of the invention is to provide a device for aligning the crystal with the crystal axis thereof in a precise relationship to an annular cutting member.

Still another object of the invention is to provide a device for forming the slices with smooth surfaces by effectively reducing the cutting resistance.

A further object of the invention is to provide a device for forming slices of consistently equal thickness with a high degree of precision.

A still further object of the invention is to provide a device for readily removing the cut slices from the cutting device.

BRIEF DESCRIPTION OF THE DRAWING These and other objects and additional advantages of the invention will become apparent from the following detailed description revealed in conjunction with the attached drawing wherein:

FIG. I is a front elevation view of the cutting device;

FIG. 2 is a plane view of the cutting device shown in FIG. 1;

FIG. 3 is a partial vertical section of the table head taken along the line A-A of FIG. 2;

FIG. 4 is a horizontal section of the table head taken along the line B-B ofFIG. 3;

FIG. 5 is a partial vertical section of the crystal holder taken along the line C-C of FIG. 1'.

FIG. 6 is a schematic partial sectional view showing the relation between the cutting member and the crystal. as well as between the base plate and the table head;

FIG. 7 is a partial vertical section of the crystal feed means taken on the line A-A of FIG. 2;

FIG. 8 is a horizontal section of the crystal feed means taken on the line D-D of FIG. 7;

FIG. 9 is an enlarged partial vertical section of the crystal which is being cut into slices by the annular cutting member;

FIG. I0 is a horizontal section taken on the line E-E of FIG. 12;

FIG. I] is a front view of the crystal holder which is attached to the table head;

FIG. 12 is a side view of the crystal holder shown in FIG. 1];

FIG. 13 is a partial vertical section of the cutting member. the spindle and the take-out means;

FIG. 14 is a plane view of the pedal mechanism as shown in the lower part of FIG. 13; and

FIG. I5 is a partial plane view of the receptacle which is positioned in the cutting member as shown in the upper part of FIG. [3.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings wherein like reference numerals are used to designate the same as similar parts throughout the several views, and more particularly to FIGS. 1, 2 and 13. a frame I having a base plate 2 and cover 3 encloses a cutting means 4. rotary member 5 and take-out or removal means 6. A block 7 is attached to the base plate 2. and a sliding table 8 is fitted on the block 7. A table head 9 is fixed on the sliding table 8. and a crystal holder 10 is attached to the table head 9. The crystal holder I0 has a crystal feed means I l on the top portion thereof.

The rotary member 5 includes a spindle holder 12 having a cylindrical hole 13 centrally disposed therein and a flange 14 outwardly extending from the upper portion thereof. Flange 14 is secured to the base plate 2 by conventional means such as bolts 15. A spindle 16 having a longitudinally extending bore 17 is vertically positioned in the cylindrical hole 13, and a sleeve 20 is mounted between the bearings I8 and I9 so as to rotatably support spindle [6. A pulley 21 is fixed to the lower end of the spindle [6 by conventional means such as nut 22. The pulley 21 is driven by a DC motor (not shown in the illustration) through a belt 23. The top end of the spindle 16 has an outwardly extending flange. and an annular protuberance 24 is formed on the top portion thereof.

The cutting means 4 is attached to the annular protuberance 24 and includes a cup-shaped chuck body 25 fitted to the spindle 16, an annular frame 26 bolted to the chuck body 25, and an annular cutting means 27 having a cutting edge described more fully hereinafter. The chuck body 25 is apertured with a large number of tiny holes 28 and includes a flange having a fitting surface 29 which is positioned at a right angle with relation to die longitudinal axis of the spindle 16. The annular frame 26 has an upwardly extending annular protuberance 30 circurnferentially formed thereon. The annular cutting means 27 is provided with a lower ring 31, an upper ring 32 and an annular cutting member 33. The annular cutting member 33 has a cutting edge 34 which is embedded or bonded with diamond dust on an apertured portion of an annular plate 35. The annular cutting member 33 is positioned between the lower ring 31 and the upper ring 32. Annular cutting means 27 is bolted to the annular frame 26 by a large number of bolts 36 that are arranged about the circumference of the lower ring 31. The annular protuberance 30 of the annular frame 26 exerts an upward force relative to the circumference of the annular plate 35, and creates tension within the entire portion of the annular plate 35. The annular cutting member 33 does not transform or shift in position due to the circumferential tension therein when cutting resistance acts on the cutting edge 34.

The cutting means 4 and the spindle 16 are rotated as a unitary member by driving force from a DC motor. The speed of rotation would be defined by the desired conditions, and could be, for example, chosen in the range of 2,000-6,000 rpm.

The take-out or removal means 6 is hereinafter described with reference particularly to FIGS. 13 to 15. A supporting plate 37 is attached to the spindle holder 12, and both a pipe holder 38 and a bracket 39 are bolted to the supporting plate 37. The lower end of a pipe 40 is inserted into a bushing 41 located in the bracket 39 and is sealed about the periphery by seal 42. The upper portion of the pipe 40 is inserted into the center hollow 17 of the spindle 16. The upper end of the pipe 40 is supported by a bushing 43 which is made of plastic material or the like. The pipe holder 38 supports the pipe 40. A block body 44 is fixed closely to the under surface of the bracket 38, and a water pipe 45 is threadedly secured to the block body 44. A shaft 46 is inserted into the block body 44 and is sealed about the periphery by seal 47. The shaft 46 extends through the pipe 40. A water pass 48 which is connected to the water pipe 45 is formed between the shaft 46 and the pipe 40, and a bushing 49 having a slit 50 is attached to the upper end of the shaft 46 for preventing vibration.

A receptacle 51 is fixed on the top end of the pipe 40, and the upper portion of the shaft 46 is extended upwardly through the base of receptacle 51 at the center thereof. A tube 52 is connected to the slit 50 which is in fluid flow communication with the water pass 48, and the end of the connecting tube 52 is connected with a nozzle 53 which is fixed at the side wall of the receptacle 51. A pair of rails 54 are attached horizontally in the receptacle and two spaced poles 55 are provided for stopping rotation of a receiving table as described hereinafter.

A rotary arm 56 is fixed to the top end of the shaft 46 within the receptacle 51, and a slide block 57 having a long groove 58 formed thereon is attached to the lower surface of a receiving table 59. Both the slide block 57 and the rotary arm 56 are connected to the shaft 46 by a stopping screw 60 which is inserted through the groove 58. The receiving table 59 has an oval shape and is attached to the top of the shaft 46 at one side thereof. A pair of elongated slits 61 are aligned with the poles 51 and are formed on the receiving table 59. An upstanding wall portion or fringe 62 is formed at the border of the receiving table 59, and rises to a higher elevation at one side. A link 63 is rotatably attached to a pivot 64 and the top head of the pivot 64 is positioned between the two rails 54. The other side of the link 63 is joined with another pivot to be able to rotate at the end of the rotary arm 56.

A stand 65 is fixed to the frame 1 with a bearing boss 66 attached to the stand 65, and a pedal stand 67 is inserted in the bearing boss 66 so as to be rotatably mounted therein. A pedal 68 is provided so as to rotate to various positions about the axis line of the shaft 46 through a pivot 69 attached to the pedal stand 67. The lower end of the shaft 46 is connected with the top of the pedal 68 through a connecting link 70, and a tension spring 7] is suspended between the pedal 68 and the pedal stand 67. A roller 72 is attached to the free end of the pedal 68 to ride on a guide rail 73 which is provided on the frame 1. This guide rail 73 is positioned so as to adjust the position of the roller with the roller 72 out of place on the guide rail 73 when the pedal 68 rotates in the horizontal plane as shown in dotted line in FIG. 14. A pair of stops 74 are arranged on the stand 65, and are contacted by the pedal stand 67 through adjusting screws 75 which are threadedly engaged with the stops 74 for controlling the swing angle of the pedal stand 67.

The operation of the take-out or removal means 6 is described hereinafter as related to the above described apparatus. The spindle 16 is driven by conventional drive means through the pulley 21. Consequently, the chuck body 25, the annular frame 26, the lower and

upper rings

31 and 32 and the annular cutting member 33 are rotated as a unitary body. The crystal 76 of silicon and other material as shown in FIG. 9, is held vertically, as described hereinafter and is fed downwardly at an interval of predetermined desired dimension into the aperture of the cutting edge 34 in the annular cutting member 33. The crystal is cut by moving it into the cutting edge 34 along the horizontal plane. The slice 77 as formed by the above described movement is dropped downwardly onto the receiving table 59 when the crystal 76 has been moved through a distance equal to the size of the crystal diameter from the initial contact point of the crystal 76 and the cutting edge 34. When the slices 77 are stacked on the right hand side of the receiving table 59 which is shown in FIG. 15, an operator operates the pedal 68 and as a result of this operation the pedal 68 is turned counterclockwise as shown in FIG. 14. At this time, the pedal 68 is not moved downwardly since the roller 72 is in contact with the guide rail 73. The shaft 46 is rotated by the above described movement of the pedal. The rotary arm 56 is consequently rotated counterclockwise by the rotation of shaft 46, as shown in FIG. 15. Therefore, the pivot 64 is moved to the left through the link 63, and the receiving table 59 is moved to the left along the rails 54, since the head of the pivot 64 is positioned between the rails 54. As the receiving table 59 begins to move to the left, poles 55 are inserted into the long slits 61. When the cut slices 77 on the receiving table 59 are stacked to an elevation approaching the height of the cutting edge 34 of the annular cutting member 33, the roller 72 attached to the pedal 68 is moved to a position disengaging the guide rail 73. As a result of such disengagement the pedal 68 is moved downward and the shaft 46 is moved upwardly. Consequently, the rotary arm 56, the link 63 and the receiving table 59, which are all attached to the shaft 46, are moved upwardly together, and the fringe 62 of the receiving table 59 is projected above the surface of the cutting edge 34. When in this position the slices can be readily removed. After the slices 77 have been removed, the receiving table 59 is moved downwardly by the tension force of the spring 71 once the operator's foot has been lifted from the pedal 68. The pedal 68 will return to the initial position, being turned clockwise, and the receiving table 59 is also returned to the initial position. During this movement, the pivot 64 is disengaged from the rails 54 when the receiving table 59 is elevated, but the receiving table 59 is prevented from rotating since the poles 55 engage the slits 61 and do not allow the receiving table 59 to move in the circular direction.

Moreover, during the cutting operation, any resulting chips are released through the tiny hole 28 by centrifugal force which is a result of the high speed rotation of the chuck body 25. The chips are mixed with water flowing from the nozzle 53 through the connecting tube 52, the slit 50, the water pass 48 and the water pipe 45.

With reference particularly to FIGS. 1 through 6, the block 7 is attached to the base plate 2 by means of bolt 78 extending through a shim 79 and by a bolt 80. A wedge 81 is positioned to move in the horizontal plane by an adjusting screw 82. Consequently, the block 7 can be adjusted within a minute angle with respect to the base plate 2 when the wedge 81 is moved to the right or left. A sliding table 8 is arranged on the block 7 to be reciprocated right and left through a feed screw 83 connected to the driving means through a conventional V-belt and gearing. The stroke of the sliding table 8 which is moved reciprocally right and left, is controlled by two feelers 84 which are fixed to the front surface of the sliding table 8. In the position shown in FIG. 1 and FIG. 2, the feeler 84 on the right hand pushes down on actuator 86 for a right hand limit switch 85. The sliding table 8 will move toward the right once signaled through the limit switch 85. The movement to the right by the sliding table 8 is continued until the left hand feeler 84 contacts the actuator 86 in the left hand limit switch 85. The desired stroke of the sliding table 8 is controlled by the space between the feelers 84. On the front of the left feeler 84 and a short distance thereabove is fixed a feeler 87 and a limit switch 88 is operated by the feeler 87 and is located at a corresponding position of the left hand limit switch 85.

A table head 9 is bolted to the sliding table 8 and a bracket 89 is formed on the table head 9 which is moved by the stroke of the table 8. As shown in FIG. 3 and FIG. 4, the bracket 89 has two parallel side walls 90. A supporting pin 91 is fitted between the side walls 90 and a head 92 is attached to the supporting pin to pivot thereabout. The head 92 has a pair of protuberances 93 in a V-shape which is fitted with a doretailed groove and a boss 94 with a threaded aperture therein formed on the left end thereof. A stepped portion 95 is formed on the right end of the head 92. A cylinder 96 is secured by bolt 97 to the stepped portion 95. Threaded portions 98 are formed by providing a reduced diameter at each end of the cylinder 96, and are inserted into arc-shaped grooves 99 which are formed on the side walls 90. A nut 100 having a lever 101 affixed thereto is attached to each of the threaded portions 98 projecting from the side walls 90. A threaded portion 102 is formed on one end of supporting pin 91, and a nut 103 having a lever 104 affixed thereto is attached to the threaded portion 102.

At substantially the center of the head 92 a pin 105 is positioned and a pressure means or dashpot 106 is pivoted thereon to rotate about a supporting shaft 107 which is in turn attached to each side wall 90. The pressure means 106 operates a piston 108 to be downwardly displaced at any time by air pressure. A block 109 is threadedly affixed to the end of the piston rod 110 and is connected with the pin 105. Between the side walls 90 to the right of the pressure means 106, an angle adjusting means 111 is provided to engage cylinder 96 at a right angle to the line extending from the center of the supporting pin 91 to the center of the cylinder 96. The angle adjusting means 111 consists of a sleeve 112 having a scale 113 which is graduated along the periphery thereof, a spindle 114 which is threadedly engaged with the sleeve 112 and in contact with cylinder 96 at the end thereof, and a thimble 115 having a circular scale about the periphery of its lower end and being fixed to the upper end of the spindle 114.

A holder plate 116 having a groove 117 is inserted into the V-shaped protuberance 93 and a center pivot 118 is provided at the center of the holder plate 116. An adjusting screw 119 is threadedly engaged with a boss 94 and is inserted through bushing 120 fixed to the holder plate 116. Screw 119 is prevented from movement in the direction of the axis of the bushing 120 by a knob 121 which is attached to the end thereof. A crystal holder 122 is secured to the holder plate 116 by two screws 123 each having a lever 124. The center pivot 118 is positioned to engage an aperture in the crystal holder 122.

The crystal holder 122 has two are shaped grooves 125 defined by a circle having its center at the center pivot 118 and is secured by screws 123, as shown in FIGS. 4 and 5. The crystal holder 122 consists of a case 126 having side plates 127 which are opposite each other, a cover 128 in contact with case 126, a pair of pressure bodies 129 for exerting pressure on two sides of a holding wood piece 130 and for securing the crystal 76, as shown in FIG. 10. On the side of the case 126, a stepped portion 131 is formed, and a cylinder 132 is secured thereto by a bolt 133, as shown in FIG. 5. An angle adjusting means 134 is attached to the holder plate 116, and is directed at a right angle to the center of the cylinder 132 and to the line extending from the center of the center pivot 118 to the center of the cylinder 132. The angle adjusting means 134 is of the same type as the above described angle adjusting means 111, and includes a sleeve 135, a spindle 136 and a thimble 137.

Referring now to FIGS. 10 through 12, a T-shaped groove 138 is formed longitudinally on the side plate 127 and three hinges 139 are positioned in the groove 138, so as to be able to slide upward or downward therein. The cover 128 is finished smoothly on its inner surface and is hinged to each of the hinges 139. The cover 128 has a window 140 formed as an elongated slit and three recessed portions 141 fonned at the side opposite the hinges. Three studs 142 are threadedly engaged with side plate 127 at positions corresponding with each of the recessed portions 141 in the cover 128. A set plate 143 having a knob 144 is supported by each stud 142 and is moved in the horizontal plane for engaging the cover 128. A threaded knob 145 is secured to the top of each stud 142 for fixing the set plate 143 when it is engaged with the cover 128. A compression spring 146 is attached to each stud 142 between the side plate 127 and the set plate 143 for pushing the set plate 143 outwardly when the threaded knobs 145 are loosened.

A positioning plate 147 is fixed to the center of the side plate 127 adjacent hinges 139 and has parallel upper and lower surfaces and an arcuate shaped periphery forming a segment of a circle with the center at the pivot of the hinge 139. At the outer end of the positioning plate 147, a latch 148 constructed of steel strips is mounted, and the latch 148 operates as a stop. A pair of brackets 149 are fixed to the cover 128 at equal distances above and below the positioning plate 147. A set screw 150 is secured to each bracket 149, and the tip of each set screw 150 is in contact with the positioning plate 147. The lower end of the cover 128 includes a downwardly projecting piece 15 1.

The pressure bodies 129 are attached to both the side plate 127 and the case 126. Each pressure body 129 consists of a pressure rod 152, a compression spring 153 which is attached to the pressure rod 152, and an adjusting screw 154 for adjusting the compression force. A contact plate 155 is mounted on the pressure rod 152 such that the contact plate 155 holds the wood piece 130 to engage and rush the crystal 76. A strip of material 156, such as plastic, is fixed so the back of the crystal 76, as shown in FIG. 6. The crystal 76 is fed downwardly by the feed means 157 as described hereinafter.

Referring now to FIGS. 7 and 8, a plate 158 is attached on the top end of the crystal holder 10, and a block 159 is attached to the plate 158. A follower body 160 has an inner thread 161 oriented in the axial direction and helical teeth 162 about the periphery thereof. The body 160 is supported by the bearings 163 which are inserted into the block 159, and a long feed screw 164 is engaged with the inner thread 161 in the follower body 160. The feed screw 64 has a high precision finished thread and projects through an upper plate 165 which is fitted on the block 159. The bottom end of the feed screw 164 is in engagement with the top end of the holding wood piece 130 which is supporting the crystal 76. A stopping block 166 is provided on the top end of the feed screw 164. A cut off portion 167 is formed on the periphery of the stopping block 166 and is in engagement with a fixed pole 168. The pole 168 is fixed in a cylindrical cover which extends from the upper plate 165 to a top cover 170 mounted on the top end of the cylindrical cover 169. A limit switch 171 is attached to the underside of the top cover 170. The limit switch 171 operates for setting the upper limit of the feed screw 164 when the feed screw 164 is fed upwardly. A worm gear 172 is in engagement with the helical teeth 162 at a right angle to the axis of the follower body 160. The thread of the worm gear 172 is formed as a dual lead, and each end of the worm 172 is held by a bearing 173. A knob 174 is attached to the worm gear such that the gear 172 is turned by hand rotation of the knob 174. The back end of the worm 172 is connected with a drive shaft 175 in a pulse motor 176 which is attached to the block 159.

The member 177 as shown in FIG. 1 and FIG. 2 is a control box having various electric controls for controlling the above described mechanical movements.

For the purpose of setting the crystal 76, the operator releases the set plate 143 and cover 128 by loosening the knob I45 and pulling the knob 144 such that the cover 128 will open. The cover 128 is displaced approximately 180 degrees, and the lower end of the upper set screw 150 is engaged with the latch 148 when the cover 128 is in the fully opened position such that the cover 128 will not be inadvertently displaced. The crystal 76 is inserted between the side plate 127 of the case 126 and the contact plate 155 which exerts pressure thereon by means of the side pressure body 129. The crystal 76 is then positioned in the case 126 by pushing the contact plate 155 backward toward wall 123 and the cover 128 is then closed. The cover 128 is secured by engaging the set plate 143 therewith and turning the knob 145. The crystal 76 is kept in the desired position by the resistance created from the pressure force exerted on the contact plates 155. As a result of the pulse motor 176 being driven, the worm gear 172 connected to the driving shaft 175 is turned, and the feed screw 164 is fed downward by the rotation of the follower body 160 which is engaged with the worm gear 172. The crystal 76 connected to the holding wood piece 130 is pushed downward by the feed screw [64 and is positioned adjacent the cutting edge 34 of the annular cutting member 33. At this time, the annular cutting means 27 having the annular cutting member 33 is rotating at high speed by means of another drive means, not shown. After positioning the crystal, the sliding table 8 is moved on the block 7 by operating the proper controls on the control box 177. Movement of the sliding table 8 to the right moves the bracket 89, the table head 9, the holder plate 116 and the crystal holder 10 to the right as a unit. Therefore. the crystal 76 is advanced toward the cutting edge 34 at a constant rate of speed, and is sliced as it is advanced. The movement of the sliding table 8 to the right is continued till the left feeler 84 contacts the left actuator 86 in the limit switch thus reversing the driving means such that the sliding table 8 is returned to the left. The reversing movement of the sliding table 8 is controlled such that the crystal 76 is cut completely through. The movement of the sliding table 8 is usually in the horizontal plane paralled to the plane of the annular cutting member 33, but the plane of movement may have to be adjusted in accordance with the position of the annular cutting member 33 if the annular cutting member does not lie in the horizontal plane; The annular cutting member 33, made of a thin metal sheet, is attached under high tension so as not to deform during the cutting operation. It may be impractical to always attached the annular cutting member 33 in the desired plane under tension, since it tends to take on a dish-shape. Consequently, it is undesirable to cut the crystal by feeding the crystal 76 in the horizontal plane since the surface of the crystal may be injured. In this case, it is necessary that the sliding table 8 move along an incline which is formed by the cutting edge 34 and the periphery of the annular cutting member 33. For that reason, the degree of inclination is determined beforehand along the cutting direction of the annular cutting member 33, and the wedge 81 which is attached under one side of block 7 is positioned to incline the block 7 in accordance with the predetermined angle of inclination. With the sliding surface of the table 8 inclined, the table 8 will move parallel with the inclined surface of the annular cutting member 33, such that the crystal 76 slices will have smooth and precisely parallel surfaces.

When beginning operation of the apparatus, one test piece is manufactured after the completion of the preparatory operation. The test piece is cut from the crystal 76 which is at a random position, and is used for measuring the direction of the crystal axis. The test piece is examined by X-ray, and the angle of inclination and direction of inclination are determined. The crystal holder 10 is then inclined in accordance with the measured angle. The measured value can be determined with great accuracy with the aid of the X-ray apparatus, and the angle adjustment of the crystal holder 10 must be done with the same precision of accuracy. Because the angle adjustment can be made by two angle adjusting means 111,

134, in two separate planes which intersect at right angles with each other, it is possible to incline the crystal in any direction. The method of adjusting the crystal axis angle is carried out by first adjusting in the vertical plane from the front view by loosening the nuts 100, moving the spindle 114, by turning the thimble while observing the scale, and turning the head 92 about the supporting pin 91. The crystal axis is generally inclined within a range of 7 degrees, and in the present application the range is limited to 2 to 3 degrees. This device is of rather high precision, because it can be adjusted within minute degrees by use of the graduated scale on thimble 115. A weight imbalance will result from the turning movement about pin 91, and the pressure means 106 operates to compensate for the weight imbalance. As the pin 105, which is positioned to the right of the supporting pin 91, is pushed down by the pressure means 106, the head 92 receives a clockwise movement, and balance is maintained. Consequently, the head 92 can be easily rotated with little force. When the desired location is obtained, the head 92 is fixed in position by tightening the nut 100. The angle adjustment in the vertical plane which intersects at a right angle with the above adjusted vertical position is obtained by turning the thimble 137 in the angle adjusting means 134 through the desired degree after the screws 123 have been loosened and the spindle I36 is moved up and down to turn the crystal holder 10 about the center pivot 118. When the angle adjustment is completed, the crystal holder 10 is secured by tightening the screws [23. To align the center of the crystal 76 and the center of the cutting edge 34, the adjusting screw 9 is rotated by the knob 121 such that the rotation of the adjusting screw 119 moves holder plate 1 16 against the table head 9.

As a result of the angle adjustment, the distance S as shown in FIG. 9, from the cutting edge 34 to the lower end of the projecting piece 151 in the cover 128 is not always that desired. The distance 8 is set to the desired value by moving the cover 128 up or down. The cover 128 is moved downwardly by loosening the upper set screw and tightening the lower set screw 150. When the desired position is reached, the cover 128 is held in position by each set screw 150. when the cover 128 is to be moved upward the operation of the set screws is reversed. When the cover 128 is moved up or down as described above, the hinges 139 will slide in the T-shaped groove 138 formed in the side wall 90.

The preparatory process is not completed for cutting the crystal 76 into slices 77 as above described, and the cutting operation is put into practice by moving the sliding table 8 to the right and left. The thickness of the cut slices 77 is required to be of very high precision. This precision can be obtained by the pulse motor 176 which operates to feed the crystal through a predetermined constant dimension. In other words, when a slice 77 is cut from the crystal 76 by a single reciprocation of the sliding table 8, a desired number of pulses are transmitted from the control box 177 to the pulse motor 176 and the pulse motor 176 will index through the desired dimension accurately in accordance with the number of pulses. Rotation of the pulse motor 176 will be transmitted to the worm gear 172 and follower body 160, such that the follower body is rotated through the desired angle. The feed screw 164 which is engaged to the follower body 160 will therefore push down on the wood piece 130 to advance the crystal through the desired dimension. The sliding table 8 will reciprocate after the crystal 76 has been fed to the desired position.

The cutting edge 34 does not sever the slices 77 from the crystal 76, but only cuts up to the point of contact with the material 156. The cutting continues in operation to produce a large number of slices 77 maintained secured by the material 156. When a number of slices 77 have been formed, they are counted in the control box 177, and even if the left limit switch 85 operates the sliding table 8 does not stop, but continues in operation until feeler 87 contacts the limit switch 88. At this point, movement of the cutting edge 34 will continue through the entire crystal 76 and material 156. The slices 77 are kept in a group by the material 156, and are removed periodically.

From the above description of the apparatus and the operation, it should be evident that the apparatus is capable of forming slices 77 which are in alignment with the crystal axis. Furthermore, the slices 77 are of uniform thickness as a result of feed means 157. Since the cutting resistance compensated for by the crystal holder 10, the slices 77 will have smooth and parallel surfaces. Moreover, the slices 77 which are easily broken can be removed safely the the take-out means 6, and the removal of the slices is accomplished with relative ease.

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 details disclosed but is of a scope as defined by the appended claims.

Having now particularly described my invention,

What is desired to be secured by letters patent of the United States and what i claim is:

1. In a device having an annular cutting member provided with a cutting edge at the inner periphery thereof for cutting a crystal into slices, the combination comprising:

a base;

rotary means on said base for supporting said annular cutting member in a given plane;

drive means operatively connected to said rotary means for continuously driving said cutting member;

a block member inclinably adjustably mounted on said base;

a table slidably disposed on said block member;

a crystal holder attached to said sliding table being independently rotatable in two vertical planes which intersect each other at right angles;

feed means for intermittently feeding said crystal held by said crystal holder through a predetermined dimension;

take-out means in said rotary means opposite said cutting member from said crystal holder for receiving said crystal slices; and

means for moving said take-out means axially of said rotary means and through the central opening of said annular cutting member.

2. A device in accordance with claim 9 wherein said block member is attached at one side to said base through a wedge so as to adjust the angle of inclination thereof by movement of said wedge.

3. A device in accordance with claim 1 further including means for periodically and automatically changing the length of stroke of said sliding table.

4. A device in accordance with claim 3 wherein said means for changing the length of stroke of said sliding table includes a plurality of limit switches attached to said block member and feelers attached to said sliding table.

5. A device in accordance with claim 1 wherein said feed means includes a pulse motor and a gear mechanism connected to said pulse motor.

6. A device in accordance with claim 9 wherein said takeout means means comprises a rotatable shaft mounted for movement along its axis a receiving table attached to the top end of said shaft movable to one side in response to rotation of said shaft and movable with said shaft in the direction of said shaft axis, and means for rotating said shaft and moving said shaft along its axis.

7. A device in accordance with claim 9 wherein said crystal holder is rotatably attached to said sliding table for adjusting the crystal axis in two planes which intersect at right angles with each other, and further comprising two angle adjusting means independently operable for adjusting the angle of inclination of said crystal holder in said two vertical planes.

8. A device in accordance with claim 7 wherein said crystal holder includes a cover movable relative to the plane of said annular cutting member so as to adjust the distance between said annular cutting member and the lower end of said cover when said crystal holder is inclined.

Claims

1. In a device having an annular cutting member provided with a cutting edge at the inner periphery thereof for cutting a crystal into slices, the combination comprising: a base; rotary means on said base for supporting said annular cutting member in a given plane; drive means operatively connected to said rotary means for continuously driving said cutting member; a block member inclinably adjustably mounted on said base; a table slidably disposed on said block member; a crystal holder attached to said sliding table being independently rotatable in two vertical planes which intersect each other at right angles; feed means for intermittently feeding said crystal held by said crystal holder through a predetermined dimension; take-out means in said rotary means opposite said cutting member from said crystal holder for receiving said crystal slices; and means for moving said take-out means axially of said rotary means and through the central opening of said annular cutting member.

6. A device in accordance with claim 9 wherein said take-out means means comprises a rotatable shaft mounted for movement along its axis , a receiving table attached to the top end of said shaft movable to one side in response to rotation of said shaft and movable with said shaft in the direction of said shaft axis, and means for rotating said shaft and moving said shaft along its axis.