US 3689820 A
In an indexing control device for a tool storage magazine having a plurality of index positions, each of which has a specific decimal number coded by binary coded decimal elements, the tool storage magazine is divided into a plurality of regions by means of the upper figures of the decimal numbers. The index control device comprises first and second discriminating circuit means, one of which selects the rotating direction of the magazine in to index the region including the desired index position to a predetermined position in a shorter route by means of the upper figure, and the other of which selects the rotating direction to index the desired index position to the predetermined position in a shorter route by means of the subordinate figure of the decimal number after indexing of the region.
Claims available in
Description (OCR text may contain errors)
United States Patent Takegawa 1 1 Sept. 5, 1972  DIGITAL FINE-COARSE RAPID 2,989,680 6/1961 Weiser et al. ..318/601 X INDEXING MOTOR CONTROL 3,127,587 3/1964 Rasmussen et al.....318/601 X INCLUDING MEANS o SENSE 3,333,089 7/1967 Saylor et al. ..3l8/60l X O S DISTANCE 3,448,360 6/1969 POhl ..3 1 8/601 2,721,967 10/1955 Olin ..318/594  Inventor: Hnroyasu Takegawa, Karlya, Japan [7 3] Assignee: Toyoda Machine Works, Limited, Primary Examiner-T Lynch Kariyafshi, Aichi ken, Japan Attorney-Robert E. Burns and Emmanuel J. Lobato  Filed: Jan. 19, 1971  ABSTRACT  Appl. No.: 107,805 In an indexing control device for a tool storage magazine having a plurality of index positions, each of which has a specific decimal number coded by binary [3O] Forelgn Apphcatmn Pnomy Data coded decimal elements, the tool storage magazine is Jan. 31, 1970 Japan..' ..45/8648 divided into a plurality of regions by means of the upper figures of the decimal numbers. The index con-  US. Cl. ..318/594, 318/601, 318/602 trol device pr s s first and second discriminating 51 Int. Cl ..G05b 11/1s circuit means, one of which selects the rotating 58 Field of Search ..318/594, 601, 602 direction of the magazine in to index the region cluding the desired index position to a predetermined  References Cited position in a shorter route by means of the upper figure, and the other of which selects the rotating UNITED STATES PATENTS direction to index the desired index position to the predetermined position in a shorter routev by means of 3,243,780 3/ 1966 Bendick et al. ..318/601 X the subordinate figure of the decimal number after 3,239,736 3/ 1966 Gardberg ..3l8/594 dexing of the region 2,918,615 12/1959 Goetz ..318/602 2,823,344 2/ 1958 Ragland ..318/601 X 6 Claims, 17 Drawing Figures 23 TCP PATENTEDSEP 51912 3.688820 sum. 010F'14 PAIENTEnsEP 5l972 3.689.820 SHEET UEUF 14 PATENTEDSEP 5 m2 sum 03 [1F 14 m mm PATENTEDSEP 1912 3,689,820
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SHEET 120F 14 PATENTEDssP' 5 m2 3,689,820 sum 130E 14 DIGITAL FINE-COARSE RAPID INDEXING MOTOR CONTROL INCLUDING MEANS TO SENSE SI-IORTEST DISTANCE SUMMARY OF THE INVENTION This invention relates to an indexing control device for a rotating body having a plurality of index positions, and more particularly relates to a rapid indexing control device which indexes a desired index position of the rotating body, such as a tool storage magazine of a machine tool provided with an automatic tool changer, to a predetermined station in a shorter route.
Outlining the method as performed by the device of the present invention, a tool-identifying means identifying the tool-receiving portions of a rotating body is provided in the automatic tool-changer in order that the rotating motion of the rotating body in a forward or reverse rotating directionis controlled by means of the tool-identifying means to index a desired and commanded tool, or a commanded tool-receiving portion of the rotating body, rapidly to a predetermined toolchange position or a predetermined machining position of machine tools.
On the other hand, it is generally known that a toolstorage magazine of a machine tool is rotated after being discriminated as to which of the two routes in the forward or reverse rotating direction thereof is shorter. However, it has not been known heretofore for each tool receiving portion of the magazine to be given a code relating to each kind of work tool and the selection of a desired tool out of the work tools as well as the discrimination of the shorter route for the rotating body in a forward or reverse rotating direction in order for the selected tool receiving portion to arrive at the predetermined tool change position, to be performed on the basis of the codes of the coded tool-receiving portions.
Recently, according to machine tools provided with an automatic tool changer which are widely used, it is necessary that the machine tool is capable of performing many kinds of complicated machining processes. As a result of this, the number of stored tools in the magazine is inevitably increased and accordingly, the size of the magazine increases.
Therefore, it became clear that coding the identifying symbols of the tools is more effective and economical for identification of a large number of work tools than to simplify a large number of identifying elements of the work tools. Accordingly, the tool-storage magazine, provided with a code device relating to the tool receiving-portions of a so-called address-type tool magazine, each of which corresponds to each work took, is widely adopted. Thus, it has been widely applied to code the tool-receiving portions of the toolstorage magazine, but the tool magazine could not be rotated in more than one direction to detect the commanded tool and consequently, it often occurred that the tool magazine had to be rotated by almost one complete rotation to obtain a desired tool, even if the desired tool had been positioned adjacent to the tool in the actual index position. Thereupon, if the magazine is 4 discriminated as to which of the two routes is shorter in a forward or reverse rotating direction of the magazine to index the stored position of the commanded tool, to the tool change position, it is possible to take the desired and commanded tool out of the tool magazine with the rotating motion of the magazine by less than degrees and it is also possible to shorten the toolsection time.
Taking this into consideration, the present invention provides the following features and advantages.
In accordance with one of the features of the present invention, each of the index positions of the rotating body, such as a tool-storage magazine, is given a code and by applying each code, the shorter rotating direction of a desired index position to a predetermined tool-change position is discriminated to control the rotating direction of the above-mentioned rotating body. Also, in the case when there is a large number of index positions, the entire index positions are divided into a plurality of groups. There is provided a rotating direction-discriminating means to the automatic tool changer, responding to the above-mentioned code, which controls the rotating direction of the rotating body so as to be rotated in the shorter route by discriminating the difference between the groups of the actual index position and the subsequent desired index position by applying the above-mentioned code. (The actual position is defined hereinafter as the index position which has been indexed to the position read by the reading device.)
The rotating direction-discriminating means also controls the direction of the body so as to be rotated in the shorter route in case the actual and subsequent desired index positions belong to an identical group.
Therefore, as the rotating direction-discriminating means is operated first in response to only the code which commands the group, the device can consist of simple logical circuits even if a large number of work tools is used. Also, in the case when the actual and subsequent desired tools belong to an identical group, the logical circuits for discriminating the rotating direction also consist of the comparatively simple arrangement of circuits, since the number of index positions belonging to each group can be reduced and the same logical circuits can be applied commonly to each group.
Consequently, the binary-coded decimal code can be used as a preferred example of the above-mentioned code. c
When the binary-coded decimal code is applied, it is possible to apply the upper figures of the decimal code to the discrimination of the difference between the groups, and the subordinated figure of the decimal code to the discrimination of the rotating direction in case the actual and subsequent commanded index positions belong to an identical group.
Besides, since each group has the same unit figurecode arrangement, the same rotating direction-discriminating means by applying the unit figure-code can be used in common in every group.
Therefore, it is an object of the present invention to provide a quick index-control device for a rotating body which can discriminate the shorter rotating route in a forward or reverse rotating direction of a so-called address type tool magazine, wherein various kinds of tools related to a plurality of tool-receiving portions are discriminated by the tool identifying code corresponding to the tool-receiving portions.
Another object of the present invention is to provide a quick index-control device for a rotating body which can discriminate the shorter rotating route in a forward or reverse direction of the tool-storage magazine, of which, the work tool-storage region is divided into a plurality of regions by applying the tool-identifying code, while being discriminated as to whether both tool storage regions of the actual and subsequent command tools are identical or different.
A further object of the present invention is to provide a quick index-control device for the rotating body which can control the tool-storage magazine so as to rotate along the shorter rotating route in a forward or reverse direction while discriminating whether both storage regions of the actual and subsequent commanded tools are identical or different by applying the binary code corresponding to the upper figure of the decimal code used as the above-mentioned tool identifying code, as well as by applying the binary code corresponding to the subordinate figure of the decimal code in case both the above-mentioned storage regions are discriminated to be identical.
The foregoing and other objects of the present invention will become fully apparent from the following descriptions of preferred embodiments of the present invention with reference to the accompanying drawings, in which:
FIG. 1 is a front elevation view of a machine tool having an automatic tool-changer,
FIG. 2 is a perspective view of a model of the toolstorage magazine forming a part of the automatic tool changer,
FIG. 3 is a partially cut out developed view of an embodiment of the coding drum forming identifying codes by a dog arrangement,
FIG. 4 is a schematic plan view of the magazine for illustrating the operation theory of the present invention,
FIG. 5 is a diagram of the control circuit for the electric power circuit of a drive motor for the tool-storage magazine,
FIG. 6 is a diagram of the relay circuit responding to the tape command and the code of the dog arrangement according to an embodiment of the present invention,
FIG. 7 is a diagram of the relay circuit for converting a binary number to a decimal number according to an embodiment of the present invention,
FIG. 8 is a diagram of the detecting circuit for the coincidence of the commanded storing region with an indexed storing region according to an embodiment of the present invention,
FIG. 9 and FIG. 10 are diagrams of the direction-discriminating circuits according to an embodiment of the present invention, in which the rotating direction of the magazine is controlled by discriminating the difference between the storing regions of the actual and subsequent commanded tool,
FIG. 11 and FIG. 12 are diagrams of the directiondiscriminating circuits to control the rotating direction of the magazine within an identical storing region according to an embodiment of the present invention,
FIG. 13 is a diagram of the detecting circuit for the coincidence of the commanded tool and indexed tool according to an embodiment of the present invention,
FIG. 14 through FIG. 17 are schematic plan views of the magazine and diagrams of the electric control circuits for illustrating another modified embodiment according to the present invention in which FIG. 14 is a schematic plan view of the magazine,
FIG. 15 is a diagram of the modified detecting circuit of FIG. 8,
FIG. 16 is another modified direction-discriminating circuit of FIG. 9 and FIG. 10,
FIG. 17 is a diagram showing a part of another modified coincidental circuit of FIG. 13.
FIG. 1 shows a whole arrangement of a machine tool having an automatic tool changer, wherein reference numeral 1 is a bed on which is arranged a column 2 having a vertical sliding surface 3 formed thereon for slidably guiding a spindle head 4. I
This spindle head 4 is threadedly engaged with feed screws, (not shown), which are operated by a motor 6 through a reduction mechanism 5 so that the head 4 is given a vertical feed motion.
The spindle head 4 is provided with a power-driven main spindle 7 rotatably mounted thereon and formed in a socket at the end thereof which receives various kinds of removal tools T, and contains a tool clamping mechanism. Reference numeral 8 is a cylinder for counter-balance against the weight of the head 4. A chain 9 is connected at its end to the end of the piston rod of the cylinder 8 and connected to the spindle head 4 at the other end thereof, so that the weight of the spindle head 4 is balanced by means of hydraulic power.
On the bed 1, a guide way 10 is formed along the axis of the spindle 7 to slidably guide a saddle 11 on top of which a guide way 12 is formed along an axis perpendicular to the axis of the spindle and guides a work table 13.
A workpiece W is mounted on a power driven index table 14 rotatably arranged on the top of the worktable 13, so that each different surface of the workpiece faces the spindle 7 by the necessary dividing operation of the index table 14. The above-mentioned saddle 11 and work table 13 are engaged with each other by respective feed screws (not shown), which are operated by motors 17 and 18 through the reduction mechanisms 15 and 16. The above-mentioned motors 6, l7 and 18 are operated in response to the command transmitted from a numerical control apparatus (not shown), to give a feed motion in three-dimensional directions. A drive motor of the index table 14 is similarly controlled by the command from the numerical control apparatus.
Many kinds of systems may be applied to the automatic tool changer to change the tools of the spindle provided for the above-mentioned spindle head 4. In the embodiment shown in FIG. 1, the automatic tool changer comprises a plurality of supporting pillars 20, a chain-type tool-storage magazine 22 disposed on a base plate 21 supported on the top of the pillars 20 over the column 2, a tool-indexing apparatus 23 which indexes each socket 22a of the magazine 22 to a predetermined tool change position TCP, a sub arm 24 removing or returning a tool T at this tool-change position, a toolholding socket 27 rotatably supported on a bracket 26 secured to a carriage 25 following the displacement of the spindle head 4, and a main change arm 28 which is rotatably mounted on the top portion of the spindle head 4 and changes tools in the tool-holding socket 27 and the spindle 7 simultaneously. The above-mentioned carriage 25 is slidably supported by the guide bars 30 arranged on the column 2, and has an arrangement in which the carriage 25 travels along the center of the spindle 7 while maintaining a predetermined relative position as shown in FIG. 1, by feed screws 32 which are operated by a motor 31 actuated by a followup type servovalve (not shown). The carriage can also be moved to the position where the tools are delivered by the above-mentioned sub arm 24, when the carriage 25 is released to travel along the center of the spindle 7. The tool-holding socket 27, which moves together with the carriage 25, is adapted to be pivoted by 90 to a ready position from the shown waiting position where the socket 27 is free from interference with the workpiece W. The tool is removed by the axial movement of the sub arm 24 from the magazine 22 to the socket 27, being transferred by the main arm 28 from the socket 27 to the main spindle 7 when the tool socket 27 is in the axially horizontal situation after it has been pivoted by 90 from the waiting position. The detailed arrangement of the index apparatus 23 for the magazine 22 is shown in FIG. 2 as an example according to the present invention.
The roller chains 56 connecting a plurality of sockets 22a with each other, are provided with chain rollers 57 engaged with a plurality of sprockets 23, one of which is shown in FIG. 2, which are rotatably mounted on the above-mentioned base plate 21 by means of a supporting shaft 33.
One of the sprockets 32s which is shown in FIG. 2, cooperates with the output shaft 40 of a motor Ml having a brake, through a worm wheel 34 mounted on the supporting shaft 33, a worm 35, a worm-shaft 36, a spline-coupling 37, and gears 38 and 39. An index plate 41 fixed coaxially on the supporting shaft 33 is provided with notches 41a formed therein, of which, a pitch corresponds to the pitch between each socket 22a. Adjacent the notches 41a, there is provided a plunger 43 reciprocally moved into and away from the notches 41a by a hydraulic actuator 42.
At the rear of this actuator 42, there protrudes a rod 42a having a dog 44 at the end thereof and a limit switch LSQ adjacent the dog 44.
The dog 44 operates the limit switch LSQ to ascertain the engagement of the plunger 43 with one of the notches 41a.
A gear 45, arranged coaxially with the above-mentioned gear 38, is engaged with a gear 46. The gear 46 is connected to a dog-holding plate 47 which rotates a full turn depending on the rotation of the socket 22a by one pitch. A dog 48 secured to this holding plate 47, operates a limit switch LSD to make an And condition when the discriminating code on the later-explained coding drum is read.
At the front end of the above-mentioned worm shaft 36, there is provided an absorbing cylinder 49 which absorbs the inertia and the over-running of the worm shaft 36 when the plunger 43 is engaged with one of the notches 41a.
The absorbing cylinder 49 cooperates with the above-mentioned spline-coupling 37 to permit a limited amount of axial displacement of the worm 35.
A coding drum 50 rotates in response to the rotating motion of the sprocket 32s. On the drum shaft 53, there is provided a gear wheel 52 engaged with a pinion 51 fixedly mounted on the supporting shaft 33 in order On the outer peripheral surface of this coding drum 50, there are arranged dogs forming binary-coded decimal codes, as shown in FIG. 3. For example, the tool number 13 is formed by dogs arranged in the rows represented by LS1, LS2 and LS10.
Adjacent the coding drum 50, there is provided a reading device 55 having limit switches LS1, LS2, and LSP thereon, corresponding to respective dog rows and operated by dogs 54 (FIG. 3).
Decimal tool numbers are code by the dog arrangement on the coding drum 50, so that it is possible to discriminate the rotating direction and the desired index position of the magazine 22 by applying these decimal codes, as described hereinafter.
As mentioned above, in case the binary-coded decimal code is applied, it is possible to divide the entire sockets 22a of the magazine 22 into several groups of ten sockets 22a so as to discriminate the groups by applying the tenth figure-code of the decimal number. Therefore, if the magazine 22 is capable of storing tools, six groups of the tool-storing regions can be discriminated from each other as different codes.
It is a feature of the present invention to control the rotating body, such as a tool-storage magazine, so as to be discriminated in the rotating direction thereof by applying the tool-identifying code. According to the above feature, it is possible to perform positioning of the rotating body to the commanded index position and select the commanded tool in the shorter rotating route of the rotating body by discriminating the difference between the groups including the actual and subsequent command index positions and by discriminating the rotating direction of the rotating body when both index positions belong to an identical group.
The theory of operation of the device according to the present invention, will be described hereinafter as to the case in which the tool-storage magazine has 60 pieces of work tools as shown in FIG. 4.
First, if it is assumed that all the tools in the magazine 22 are arranged as shown in FIG. 4, the rotating directions of the magazine are defined as CW (clockwise) and CCW (counterclockwise) for each shown arrow and all the positions are divided into six regions of 00, 10, and 50 by applying the tenth figure-digits.
In the explanations hereinafter, the actual position and the subsequent commanded position of the magazine are distinguished for designation purpose by attaching the symbols L and T to the respective code.
Here, the condition and the logical condition for rotating the magazine 22 in the clockwise direction are shown in Table l, and in the counterclockwise direction in Table 2.
The actual position of the magazine The commanded tool group L00 T50 T40 L10 T00 T50 T40 L20 T10 T00 L30 T20 T10 T00 L40 T30 T20 L50 T40 T30 T20 TABLE 2 Rotating in a counterclockwise direction The actual position of the magazine The Commander! tool group L T T20 T30 L10 T20 T30 L20 T30 T40 T50 L30 T40 T50 L40 T50 T00 T10 L50 T00 T10 TABLE 3 The case of an identical group The actual The commanded position tool number The The of the (The unit rotating logical magazine figure-number) direction condition L0 T1 T9 CCW Ll T0 CW T2-T4T8 T2 T9 CCW T2 T4 T8 L2 T0 T1 CW TZ T4-T8 T3 T9 CCW T2 T4 T8 L3 T0 T2 CW T2-T8 T4 T9 CCW T4 T8 L4 T0 T3 CW T4-T8 T5 T9 CCW T4 T8 L5 T0 T4 CW T2-T8 T4-T8 T6 T9 CCW T2-T4 T8 L6 T0 T5 CW T2-T8 T4-T8 T7 T9 CCW T4-T2 T8 L7 T0 T6 CW T8 T8 T9 CCW T8 L8 T0 T7 CW T8 T9 CCW T8 L9 T0 T8 CW For example, if the actual position in No. 31 and the subsequent commanded tool is No. 27, the condition T20 in the row L30 of Table l is satisfied, so that the rotating direction of the magazine is determined to be a clockwise direction and the tool of No. 27 can be indexed to the tool-change position with a slight amount of magazine rotation.
Further, if the tool of No. 43 is commanded subsequently, the condition T40 in the row L20 of Table 2 is satisfied. Consequently, the rotating direction of the magazine 22 is determined to be a counterclockwise direction. However, the condition to select a desired tool is not limited merely to the condition wherein the actual index position and the subsequent commanded tool position belong to the different groups, respectively.
When both positions belong to an identical group,
' the rotating direction of the magazine is determined according to the condition shown in Table 3.
For example, if the tool of No. 48 is commanded subsequent to the tool of No. 43, the rotating direction of the magazine is discriminated bydiscriminating the positions of each unit digit 3 and 8 of both tool numbers. That is, the rotating direction of the magazine is determined to be a counterclockwise direction according to the condition of T4 through T9 in the row L3" of Table 3. Thus, the necessary tool selection time can be reduced according to the discrimination of the shorter rotating route of the magazine.
The logical circuits of FIG. 9 and FIG. 10, which are described in detail hereinafter, are formed in accordance with the logical condition to Table l and 2, while the logical circuits of FIGS. 11 and 12, which are described in detail hereunder, are formed in accordance with the logical condition of Table 3, whereby it is possible to attain the automatic control of the rotating direction of the magazine and the selection of the tool in the shorter rotating route.
Hereinafter, the above-mentioned logical circuits will be explained with examples of the relay circuits. Referring to FIG. 5, there is shown an electric power source circuit for the motor of the magazine-index apparatus 23.
A distributing breaker CB1 is connected to electric power supply lines R, S and T.
The relay-contacts of a motor CMCW-1 for enabling the change of the rotating direction of the motor Ml are inserted and connected between the breaker CB] and the input terminals of the motor Ml provided with a brake.
A thermal relay TYl operates when the motor M1 is overloaded, and the normally closed contacts of the relay TYl are connected in a series to the motor-relays CMCW and CMCCW.
Brake-contacts CRB-l are inserted between the breaker CB1 and a brake-coil B.
The electric power supply lines R and T are connected to the primary winding of a transformer Trl, and the secondary winding of the transformer Trl are connected to the electric power supply lines of the relays circuit and 200 through fuses F and F The relays CMCW and CMCCW, connected between the electric power supply lines 100 and 200, are energized by closing the contacts CRCW-1 and CRCCW-l to close the above-mentioned contacts CMCW-l or CMCCW-1 to rotate the motor M1 in a forward or reverse direction and as a result of this, the magazine 22, (FIG. 1) is rotated in a clockwise direction or a counterclockwise direction.
The stoppage of the 'magazine is performed by stopping the motor M1 due to the opening of the electric power source circuit depending upon the de-energizing of the motor relays CMCW and CMCCW. These motor relays CMCW and CMCCW are deenergized by opening the contacts CRCW-l and CRCCW-1 in such a manner that when the relay CR100 of the laterdescribed coincidental circuit of FIG. 13 is energized by a coincidental signal, which is generated by the magazine reaching the position in advance of the exact index position, the normal closed contact CR100-l of FIG. 9 is opened to de-energize the relays CRCW and CRCCW to open the above-mentioned contacts CRCW-1 and CRCCW-1. When the magazine is stopped, the plunger 43, (FIG. 2) is moved to the forward position under the deenergization of a solenoid SOLl and as the plunger 43 is engaged with an indexed notch 41a of the index plate 41 with the inertial rotating motion of the magazine, the limit switch LSQ is operated to energize the relay CRQl with closing of the contact CRQl-Z. As a result of this, a relay CRB is energized so that the braking power is applied to rapidly stop the motor M1 and its related mechanism.
The over-running of the magazine after the engagement of the plunger 43 is absorbed by the absorbing cylinder 49, so that the commanded index position of the magazine is accurately indexed. Also, when the motor is commanded to rotate in a forward or reverse direction, the relay CRQ2 is energized to close the contact CRQZ-l for disengaging the plunger 43 through a solenoid SOLI and a hydraulic actuator (not shown) activated by the solenoid SOLI.
Referring to the upper half of FIG. 6, a plurality of contacts T1, T2, T4, T8, T10, T20 and T40 for the command use of the tool number, which are operated to be opened or closed by the tape command signal, and relays CRTl, CRT2, CRT4, CRT8, CRT10, CRT20 and CRT40 are connected between the lines 100 and 200.
Contact TF, shown at the uppermost portion of FIG. 6, is closed with a lesser delay time than the other contacts to prevent the contacts T1 through T40 from misoperating, due to the irregularity of the opening and closing action thereof, and is opened after a short duration.
The limit switch-contacts LS1, LS2, LS40 and LSP, shown in the lower half of FIG. 6, are the respective contacts of the limit switches, which are arranged in the above-mentioned reading device 55, and are connected to relays CRLl, CRL2, CRL40 and CRLP, respectively, as well as to the contact CRD-l of the relay CRD which is connected to the above-mentioned limit switch LSD. The closing of this contact CRD-1 operates so as to align the starting time of the operations of the respective relays CRLl, and CRLP so that the actual position of the magazine can be prevented from being misread.
The limit switch LSP is applied for the parity check use of the codes.
FIG. 7 shows the binary to decimal converting circuit in which the binary code is converted to the decimal code representing the tenth figure of the decimal tool number. The relays CRL00, L and CRL50 shown in the upper half of FIG. 7 are connected to the contacts of the relays CRL10, CRL20 and CRL40, shown in the lower half of FIG. 6, which operate responding to the binary codes.
For example, the closing of the limit switches LS10 and LS40, FIG. 6, corresponds to 50 of the decimal digits, and accordingly, the contacts CRL40-2 and CRL10-6, (FIG. 7) are closed to energize the relay CRL50 only. Therefore, it will be understood that the fifties storing region including positions 50 through 59, corresponds to the tool change position TCP.
The relays CRT and CRT50 have almost similar circuit arrangement and are connected to the contacts of the respective relays CRT10, CRT20 and CRT40 (FIG. 6), which operate responding to the tape command signals. These relays CRL00, CRL CRL50 and CRT00, CRT10, and CRT50, (FIG. 7), correspond to the respective storing regions 00, and 50, (FIG. 4), which are formed by grouping the sockets 22a of the magazine, (FIG. 1). Therefore, as shown in FIG. 8, the contacts CRL00-l, CRL50-1, and CRT001, CRT50-1 are arranged so as to discriminate the difference between the storing regions belonging to the tool-change position TCP and of the commanded tool. The relay CR10 is energized only when both above storing regions are identical, and is provided with the self-holding circuit derived from the self-contact CR10-4 thereof. Accordingly, when the storing region of the commanded tool is discriminated to be identical with the storing region of the actual tool, the relay CR10 closes the contact CR10-2, (FIG. 11), and the contact CR10-3, (FIG. 12) so that the discrimination of the shorter rotating route of the magazine is performed by applying the unit figurecode.
FIG. 9 and FIG. 10 show the rotating direction-discriminating circuits in the case of different storing regions.
The relay CRCCW, (FIG. 9) directs the magazine to rotate in a counterclockwise direction.
The circuit, FIG. 9, is composed of the contacts of the above-mentioned relays CRL00, and CRL50 so that the logical conditions of Table 2 is satisfied, and is connected to the electric power supply line through the contacts CR100-l and CRTF-2. 2.
The contacts CR10-4 and CRCW-4 are inserted, in series, into the circuit for the purpose of interlocking between the forward and reverse rotating directions.
The line 110, FIG. 9, which is connected to the connecting points of the contacts CR100-l and CRTF-2 at an end thereof, is connected to the line 110, (FIG. 10) at the other end thereof.
Also, the line 120, (FIG. 9), which is connected to the other connecting point of the contact CRTF-2 at an end thereof, is connected to the line 120, FIG. 10 at the other end thereof. The contact CR1-2, 2, (FIG. 9) is connected to the circuit in parallel with the contacts CRL00, CRLSO- and CRT00, CRT50- so that the relay CRCCW is energized also when the magazine is directed by the relay CR1, (FIG. 11 to be rotated in a counterclockwise direction as a result of the discrimination of the unit figure-code. The self-contact CRCCW-3 of this relay CRCCW is connected to the line to constitute a self-holding circuit. There fore, when the magazine is directed to be discriminated in its rotating direction, and the relay CRCCW is energized by closing the contact CRTF, the self-holding circuit is set in the self-holding situation so as to maintain the situation until the commanded tool is indexed to the tool-change position TCP. When the commanded tool is selected, the relay CR100 in the coincidental circuit of FIG. 13 is energized to assure the proper selection. When the relay CR100 is energized, the contact CR100-1, (FIG. 9), is opened to release the self-holding condition of the above-mentioned self-holding circuit and to cut the electric power source of the magazine-drive motor M1. Subsequently, the indexing of the magazine is completed.
The relay CRCW of FIG. 10 directs the magazine to rotate in a clockwise direction and the relay circuit, FIG. 10, is constituted from the contacts CRL00, CRL50- and CRT00, CRT50- which are connected between the lines 110 and so that the logi-