US3230807A

US3230807A - Stock positioning apparatus

Info

Publication number: US3230807A
Authority: US
Inventors: Richard D Hill
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-05-01
Filing date: 1964-05-01
Publication date: 1966-01-25
Anticipated expiration: 1983-01-25

Description

5 Sheets-Sheet 1 Filed May 1, 1964 INVENTOR. P EL'c/Lcwdfl HL'LL.

- WWI a Jan. 25, 1966 Filed May 1. 1964 STOCK POS ITIONING APPARATUS R. D. HILL 3 Sheets-Sheet 2 Jan. 25, 1966 R. D. HILL STOCK POSITIONING APPARATUS QQQQQ NMN 3 Sheets-Sheet 5 aw NO bb Filed May 1, 1964 United States Patent 3,230,807 STOCK POSITIONING APPARATUS Richard D. Hill, Glen Ellyn, Ill., assignor, by mesne assignments, to Richard D. Hill and Maurice Hill Filed May 1, 1964, Ser. No. 364,097 Claims. (Cl. 83-20?) This invention relates to stock movement control apparatus and in particular to apparatus for controlling the movement of stock such as rods and sheets in apparatus such as cut-off devices.

In many different apparatuses for working elongated stock such as strip material including rods, formed elements, sheets and the like, a means must be provided for accurately measuring a distal length of the stock so that the working operation which may comprise shearing, cutting, punching, etc., may be effected at a point accurately spaced from the distal end. As a concomitant of improved high speed mass production techniques in such forming art, it is becoming increasingly more essential that control means be provided for accurately measuring the distal lengths at high speed. The presently known devices for such length control and measurement have not proven completely satisfactory as they do not provide suflicient accuracy at the relatively high speeds at which the forming apparatuses are capable of functioning. The substantial losses in production economy have made this problem a very serious one. The present invention comprehends an improved stock measuring and control means solving this serious and vexatious problem in a novel and simple manner.

Thus, a principal feature of the present invention is the provision of a new and improved stock control apparatus.

A further feature of the invention is the provision of such an apparatus arranged to provide extremely accurate measurement of lengths of strip stock being fed at high speed from a continuous supply. 7

A further feature of the invention is the provision of such apparatus including means for engaging the moving stock and means for adjustably stopping the stock engaging means to accurately control the distal length of stock relative to a reverse or working position.

Still another feature of the invention is in the provision of such an apparatus further including means for automatically adjusting the stopping position of the stock engaging means as a function of the position of the distal end of the stock.

Still another feature of the invention is the provision of such apparatus including means for feeding stock forwardly through a working position to have a leading portion thereof disposed at a measured position spaced from the working position an accurate distance, means for clampedly engaging the stock and arranged to travel with the stock upon clamped engagement therewith, means responsive to the movement of the leading portion of the stock to a trip position intermediate the working and measured positions to cause the closing of the clamp means to engage the stock, sensing means disposed rearwardly adjacent the measured position for indicating the disposition of the leading portion, means connecting the clamp means to the sensing means for movement therewith, adjustable stop means for limiting the forward movement of the clamp means, and means responsive to an indication from the sensing means of the movement thereof to the measured position to adjust the stop means for controlling the permitted travel of the clamp to cause the clamp to be stopped by the stop means when the leading portion is accurately at the measured position.

A yet further feature of the invention is the provision of such apparatus including means permitting the sheet and the means engaging the sheet to move slightly beyond the "ice desired final position and means for reversely moving the sheet and the means for engaging the sheet accurately back to the final position.

Still another feature of the invention is the provision of such apparatus having new and improved means for quickly engaging the sheet for accurate movement there with.

Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings wherein:

FIGURE 1 is a fragmentary top plan view of an ap' paratus for working elongated sheet stock, including means embodying the invention for accurately gauging the length of the stock relative to the working position;

FIGURE 2 is a fragmentary side elevation thereof; FIGURE 3 is a diametric side elevation illustrating a first step in the gauging operation of the apparatus;

FIGURE 4 is a diametric side elevation illustrating a second step in the gauging operation of the apparatus;

FIGURE 5 is a diametric side elevation illustrating a tus of FIGURE 7 illustrating the pneumatic, hydraulic and.

electric circuitry thereof.

In the exemplary embodiment of the invention as disclosed in FIGURES 1 through 6, a stock gauging and positioning apparatus generally designated 10 is provided in association with a stock working apparatus generally designated 11 arranged to provide a working operation on an elongated workpiece such as sheet stock 12. In illustrating the invention, the stock working apparatus 11 is shown,

to comprise a cut-off device. The cut-off device illustrated is one wherein the cut-off apparatus remains fixed relative to the longitudinal travel of the sheet 12; it being understood, however, that the apparatus 10 may be employed,

with flying cut-off devices, as well as other working devices, both stationary and flying, as desired. The gauging apparatus 10 functions herein to control the disposition of the distal end 13 of the stock 12 so that the distal end has an accurate preselected length beyond the working position, which in the illustrated embodiment comprises the point at which the stock is cut by the cut-off device 11.

As shown, the apparatus 10 includes a means for engaging the sheet for travel therewith comprising a clamp 14 which is disposed rearwardly (in the direction opposite that of the travel of the stock which as shown in the figures is from right to left) of the base 15 of the cut-off die 16. The stock 12 passes through the space between the upper clamp 14a and the lower clamp 14b of the clamp device 14 and then through the cut-off die 16 to overlie a run-out table 17. In general, the cut-off device 11 is operated to sever the stock 12 transversely when a preselected distal portion 13 has passed the severing point, thereby providing a preselected length of stock which may be subsequently ejected in the conventional manner.

A serious problem arises in controlling lengths of stock with sufficient accuracy to meet the requirements of high speed mass production techniques presently employed. Illustratively, such inaccuracy results from the impossibility of applying the clamping means simultaneously, or repetitively in a fixed time period. Further, inaccuracy results from variation in the line speed of the work, as well as from the substantial accelerating forces involved in accelerating the die. The present invention functions to automatically correct for'such variation in the clamping operation and thereby permit an improved highly accurate gauging of the sheet portion 13. More specifically, the gauging apparatus includes a first switch 18 having a fiag operator 19 disposed to be engaged by the forward end 20 of the distal portion 13 of stock 12, whereby the flag 19 is pivoted and operates switch 18 to actuate the clamp 14 and cause the clamp elements 14a and 14b to be brought towards each other to clamp the sheet stock 12 therebetween. The clamp 14 is slidably mounted for movement with the sheet 12 so that the clamp moves to the left, as shown in FIGURE 3, toward the cut-off device 11 by the motion thereof with the traveling sheet. A rod 21 extends from clamp 14 forwardly to an outboard support 22 and carries switch 18 adjacent its forward end whereby the switch moves directly with the clamp 14 upon positive clamped engagement of the clamp 14 with the sheet 12.

As shown in FIGURE 3, the gauging apparatus 11) further includes a second switch 23 carried on the rod 21 forwardly of the first switch 18 and provided with a flag operator 24 which is engaged by the end 20 of the sheet stock 12 when the end 20 passes beyond the switch 18. The switch 23 is adjustably carried on the rod 21 for accurate positioning thereof relative-to the clamp 14. The spacing between switch 23 and switch 18 is made to be sufiicient to assure that the clamp elements 14a and 14b clampedly engage the sheet only after the stock end 21) engages the operator 24 of switch 23 and urges it piyotally beyond the upright zero position shown in full lines in FIGURE 3 to a pivoted position shown in dotted lines in FIGURE 3. When the clamp elements 1 a and 14b positively clampedly engage the sheet 12, the rod 21 moves, directly therewith and thus the flag 24 is maintained in the dotted line position of FIGURE 3 at this time notwithstanding the further forward movement of the sheet stock 12.

At the same time that the clamp engages the sheet 12 to initiate the movement of the clamp toward the cut-off device 11 directly with the movement of the stock 12, a power cylinder 25 is actuated to move the rod 21 forwardly somewhat faster than the movement of the clamp and stock 12. Thus, the rod 21 moves forwardly, or to the left as seen in FIGURE 3, relative to the moving stock 12 whereby the switch 23 is moved from the full line position of FIGURE 3 to the position of FIGURE 4 wherein the spring biased operator 24 returns to the vertical position as the switch 23 becomes disposed directly laterally of the sheet end 20. As the power cylinder 25 moves the rod 21 forwardly, it concurrently acts through a magnetic clutch 26 on a servo piston device 27 also carried by the clamp 14. This actuation of the servo piston device 27 causes a flow of oil through an interconnecting conduit 28 to a receiver servo piston device 29 carried by the clamp 14 and extending forwardly therefrom toward the cut-off device 11. The servo piston device 29 includes a movable output element 30 defining an adjustable stop, the position of which is controlled by the quantity of oil delivered to the receiver device 29 from the servo device 27 so that the movement of the device 29 is in one-to-one ratio with that of device 27.

Thus, the stop 30 is urged forwardly from the clamp 14, a distance exactly equal to the distance that the rod 21 is advanced relative to the sheet stock 12 by the power cylinder 25. This distance as discussed above is also exactly equal to the distance that the switch 23 moved relative to the end 213 of the sheet stock in returning the operator 24 to the vertical position. The movementof the operator 24 to the vertical position simultaneously causes a de-energization of the magnetic clutch to break the connection between the power cylinder 25 and the servo device 27, where-by the stop 30 is positively fixed in this adjusted position. The stop 38 is adapted to engage a cooperating stop block portion 31 of the cut-off device, and, thus, the adjustment thereof as discussed above effectively comprises an adjustment of the effective spacing between the clamp 14 and the cut-off device as the stop 30 comprises effectively an adjustable extension of the clamp 14.

The clamp 14 and sheet stock 12 continue to move forwardly to the final position, as shown in FIGURE 5, wherein the end of the sheet stock is at a preselected position herein defined as the measured position spaced an accurately preselected distance from the cut-01f device 11. The control of this forward movement is accurately effected by the abutment of the stop 31 with the block portion 31 of the cut-oif device positively limiting the forward movement of the stock 12, as shown in FIGURE 5. The cut-off device is then suitably actuated to cut the sheet in the accurately gauged length 13.

After the cut-off device 11 is actuated to cut the stock 12, the power cylinder is actuated to return the rod 21 to the rearward or righthand position of FIGURE 1,. and the

servo devices

27 and 29 are returned to the original rearward positions illustrated in FIGURE 3 to re-establish the apparatus for a subsequent cycle of operation.

The operation of apparatus 10 may best be seen by reference to FIGURE 6 which comprises a schematic drawing illustrating the arrangement of the apparatus in association with the electrical, pneumatic and hydraulic circuitry. In the first step of operation, the sheet material 12 moves through the clamp 14 until the leading end 13 engages flag operator 19 of first switch 18 pivoting the flag operator to the dotted line position of FIGURE 3 and operating the switch 18. As illustrated, switch 18 includes a first contact 18a connected to a first power supply lead L and a second contact 18b connected to a first solenoid 50, a second solenoid 51 and a third solenoid 52. The opposite side of each of the solenoids is connected electrically to a first contact 53a of a switch 53 having a second contact 53b connected to the other power supply lead L Thus, when switch 18' closes, each of

solenoids

50, 51 and 52 is energized. Solenoid 50 controls a valve 50a which is connected from source P of pneumatic pressure to clamp 14 to open the valve and thereby operate clamp. 14 upon energization of the solenoid. At the same time, solenoid 52 controls a valve 52a connected to pneumatic pressure source P to deliver air under pressure to the righthand side of a piston chamber 54, in which is disposed a piston 55 which is thereby moved to the right as seen in FIGURE 6.

The piston 55 is connected through a link 55a tothe base 14c of the clamp 14 to thereby accelerate the clamp mechanism to the left as seen in FIGURE 6. Further, concurrently, solenoid 51 controls a valve 510 to deliver air under pressure from source P at this time to servo mechanism 29 serving to close the oil bypass thereof.

The advancing sheet stock 12 continues to move to the left until the leading end 13 thereof engages the flag operator 24 or" switch 23. The flag operator 24 is moved by the sheet end 13 past a vertical position wherein the contacts 23a and 23b of switch 23 are momentarily closed to a final position, as shown in dotted lines in FIGURE 3, wherein the switch contacts 23a and 23b are spaced apart. Switch contact 23a is connected to power supply lead L and switch contact 23]) is connected through electric clutch coupling 26 to a first contact 56a of a switch 56. A second contact 56b of switch 56 is connected to power supply lead L Switch 56 is open at this time, and, thus, the momentary closing of switch 23 has no effect.

As clamp base moves forward, that is to the left as shown in FIGURE 6, it releases switch 56 to close contact 57a of a switch 57 with a contact 57b thereof. Contact 57b is connected to power supply lead L and contact 57a is connected to a solenoid 58 which in turn is connected to contact 53a. The closing of switch 57 energizes solenoid 58 to open valve 58a and deliver air under pressure from source P to the lefthand side of power cylinder 25, thereby moving the rod 21 forwardly 5. or to the left as seen in FIGURE 6. This concurrently pulls the servo piston device 27 to the left as the clutch 26 is energized, thereby delivering a quantity of oil from servo piston device 27 through conduit 28 to the receiver servo piston device 29, and thus moving the stop 30 outwardly from device 29 in exact one-to-one ratio with the movement of the servo piston device 27.

The movement of rod 21 to the left causes switches 18 and 23 to be carried to the left therewith and in effect repositions the

switches

18 and 23 in the arrangement of FIGURE 4 allowing the flag operator 24 to move back to the upright or vertical position to close switch 23. The closing of switch 23 at this time causes disengagement of the electric clutch 26, thereby stopping further flow of oil from servo piston device 27 to servo piston device 29 by disconnecting the servo piston device 27 from the power selector 25. This fixes the position of stop 30 at an extension to the left from its original position exactly equal to the amount of travel of rod 21 necessary to return the flag operator 24 to the vertical position.

As the cut-off device 11 continues in its cut-off stroke, it opens switch 53 thereby de-energizing each of

solenoids

50, 51, 52 and 58, thereby closing valve 50a and releasing the clamp 14, closing valve 51a thereby resetting the servo mechanism 29, closing valve 52a thereby returning the clamp 14 to the righthand position of FIG- URE 6 by urging piston 55 to right, and closing valve 58a thereby re-setting the hydraulic piston of servo mechanism 27 by moving power selector 25 to the right as shown in FIGURE 6. When the clamp base 14c moves fully to the retracted position, it closes contact switch 56, thereby re-energizing the clutch 26. Thus, the apparatus is reset for a subsequent cycle of operation similar to the above described cycle.

Referring now to FIGURE 7 of the drawings, a modified form of stock gauging and positioning apparatus generally designated 110 is shown in association with a stock working apparatus 111 generally similar to stock working apparatus 11, and, thus, herein comprising a sheet cut-off device. The gauging and positioning apparatus 110 differs from the gauging and positioning apparatus 10 in the utilization of surface measuring means generally designated 123, in lieu of the control switches 18 and 23 of apparatus 10.

Such surface measuring means are well known in the art and need no further description, other than that surface measuring means 123 herein comprises a conventional counter having a surface measuring wheel 123a and arranged to provide a coincidence count and an early warning count at a preselected number of counts less than the coincidence count. The counter 123 may, for example, comprise a counter which counts firstly from a preselected initial count, past an early warning count, down to zero, and then counts back up from zero in accordance with a continuing count. A sufli'cient number of negative counts may then be delivered to the counter to return it back to zero. Herein, the counts are effected by electric pulses obtained by the movement of the measuring wheel 123a effected by its contact with the surface of the sheet 12. One example of an industrial preset counter suitable for such use in a series 2300 counter of Micro Measurements Corporation of Melrose Park, Illinois.

Illustratively, the the wheel 123a may be arranged to provide one pulse for each .01 inch of the sheet material moving under the wheel. Thus, for example, if it is desired to provide a six foot length of sheet, the counter would be preset for 7,200 pulses whereby coincidence would occur when the counter counted down to zero. The counter further may be arranged to provide an early warning signal at some point short of the zero or coincidence point, such as when 500 counts remain. The early warning point may be set to correspond to a length difference in the sheet, such as the spacing between the

switches

18 and 23 of apparatus 10. Thus, the early warning signal may be utilized to initiate the energization of the clamp 114. The specific time at which the initia= tion of the energization of clamp 114 is effected is preselected so as to assure that the clamp does not positively cla-rnpedly engage the sheet prior to the reaching of the coincidence or zero count. Preferably, the early warning signal is set so as to assure that the counter will definitely go beyond the zero point and back up to a substantial overage count such as 25 by the time the clamp is positively engaged with the sheet surface.

The lower die 11% carries an adjustable stop 130 similar to stop 30 of apparatus 10. The stop is adjustably positioned by a servo piston device 129 which is moved in one-to-one relation with a transmitter servo piston device 127 through a fluid line 128. A lineal transducer 141 of conventional construction is arranged to transmit to the counter 123 pulses which are negative to the overage count on the counter so as to restore the counter back again to the zero or coincidence point.

When the clamp positively clampedly engages the sheet 12, the clamp moves directly with the sheet to the left as seen in FIGURE 6. After a preselected travel of the clamp, for example, one-half inch, the clamp actuates a switch 140 which gates counter 123 preventing further pulses from entering the counter from wheel 123a. Also switch 140 controls a power cylinder 125 corresponding to the power cylinder 25 of apparatus 10. The lineal transducer is operated from the power cylinder 125 which acts through a quick acting clutch 126 to urge the servo piston 127 to the left as seen in FIGURE 6, and thereby, through fluid line 128, correspondingly urge the adjustable stop 130 to the left in direct one-to-one relationship. Piston device 127 is also connected to the transducer 141 by a connecting element 142 to operate the transducer 141 so that for every .01 inch of adjustment of stop 130 the transducer 141 sends one pulse to the counter 123. This continues until the counter 123 reaches the zero position, at which time the clutch 126 is de-energized so as to preclude any further movement of the stop 130 and delivery of pulses to the counter 123.

Thus, the stop 130 has been repositioned so as to adjust the permissible movement of clamp 114 toward cutoff device 111, the correction adjustment of the stop corresponding exactly to the overtravel of the sheet portion 13 beyond the preselected length. Thus, the clamp is held back from its maximum leftwardmost positioning exactly the required distance to position the sheet accurately relative to the cut-off device.

Thus, each of the gauging and measuring

apparatuses

10 and 110 provides an automatic highly accurate gauging of the length 13 of the sheet stock 10, while yet permitting the cut-off apparatus 111 and the travel of the sheet stock to be at relatively high speeds. As each measurement of the respective lengths of stock cut from the supply is completely independent of the previous measurement, cumulative errors are completely eliminated. Maximum accuracy of the length gauging is obtained at all times as the variables such as clamping time, speed of the sheet, and the like are cancelled out automatically during each gauging operation. The gauging and measuring apparatus of the present invention is equally useful withstationary working devices and fiying working devices as the control is obtained by the relationship of the clamp as engaged with the work sheet and the cut-off device, it being obvious to those skilled in the art that the variable spacing obtained by the adjustable stops 30 and 130 may be equally well provided whether the cutoff device is moving or stationary.

The operation of apparatus 110 may best be seen by reference to FIGURE 8 which comprises a schematic drawing illustrating the arrangement of the apparatus in association with the electrical, pneumatic and hydraulic circuitry. In the first step of operation, the operator dials into a conventional electronic counter 123 the length of the stock which it is desired be cut from the rolled supply thereof. In the illustrated embodiment, the counter is arranged to count, or measure, up to 999.99 feet. As indicated, such counters are well known in the art and include internal structure for providing an early warning count which occurs a preselected number of counts prior to the coincidence count.

As the sheet stock 12 moves to the left as seen in FIGURE 8, the ocunter wheel 123a is rotated by its engagement with the upper surface of the stock and delivers a series of pulses to the counter by means of a photoelectric grid reader 12% of conventional construction. When the number of pulses delivered to the counter 123 from the grid reader 123b reaches the early warning count, the counter 123 emits an electric pulse. This pulse is delivered to a first solenoid 150 which is connected to a contact 153a of a switch 153 having a second contact 1531) connected to the power supply lead L The solenoid 150 controls a valve 150a which operates the clamp 14 in the same manner as the valve 50a of apparatus 10. Concurrently, the electrical pulse delivered through counter 123 energizes a solenoid 151 also connected to fixed contact 153 to open a valve 151a which closes the oil bypass to servo mechanism 129 in the same manner as valve 51a functions in apparatus 10. Further, concurrently the pulse from counter 123 energizes a solenoid 152 connected to contact 153a to open a valve 152a for actuating the accelerating piston 155 in cylinder 154 to move the clamp base 114a to the left in the manner described relative to apparatus 10.

The counter wheel 123a continues to be rotated by the forward movement of the sheet stock 12 sending pulses through the medium of grid reader 1231) to the counter 123 until the'counter reaches coincidence count or zero. As discussed briefly above, the counter counts up from zero after reaching the coincidence count, and is automatically stopped when the normally closed switch 157 is opened by the engagement thereof by clamp base 114C. As shown in FIGURE 8, the switch 157 includes a first contact 1571) connected to the power supply lead L and a second contact 157a connected to the input to the counter 123 in parallel with the connection thereto from the grid reader 1231;. In this connection, it should be noted that the early warning count is preselected so that some overtravel beyond the zero or coincidence count is provided at all times within the variations in the sheet stock length normally obtained in the operation of the apparatus.

The closing of switch 157 further connects a solenoid 158 from power supply lead L to contact 153, thereby opening a valve 153a to operate the power selector 125 to the left as shown in FIGURE 8. Power selector 125 is connected to the servo mechanism 127 by means of the electric clutch 126 so that the servo mechanism 127 is correspondingly pulled to the left with the power selector piston thereby delivering a quantity of oil through the conduit 128 to the receiver servo device 129 and thereby urge the stop 130 to the left in one-to-one ratio with the movement of the servo piston device 127. At the same time, the movement of the piston 127a of the servo piston device 127 pulls to the left a fiat transducer 141 which, through a pickup 141a, transmits pulses to the counter 123 causing the counter to operate in a negative direction, or back toward zero, from the count previously reached by the counter beyond the coincidence count. When sufiicient movement of the power selector 125 to the left is effected to concurrently urge the stop 130 to the left and feed a number of pulses from transducer 141 to the counter 123 restoring the counter to the zero or coincidence count, an electric pulse is transmitted from the counter to the clutch 126 to disengage the clutch and prevent further leftward movement of the servo piston device 127 and the transducer 141.

The invention has been described in connection with the gauging and measuring apparatus utilizing an overtravel of the sheet stock with an adjustment of the movement of the clamp relative to the working device such as to subtractthis overtravel in the positioning of the clamp at the cut-off time. It should be obvious to those skilled in the art, however, that a reversely similar arrangement may be employed in the apparatus within the scope of the invention, namely, an arrangement utilizing an undertravel of the sheet portion 13 with a corresponding corrective retraction of the stops 30 or directly corresponding to the amount of additional travel the clamp should be allowed to move toward the working device to compensate for the measured undertravel.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim: 7

1. Apparatus for positioning stock to extend accurately in a preselected working position, comprising:

means for feeding stock to have a portion thereof move to adjacent said working position;

means for engaging the. stock and arranged to travel with the stock upon engagement therewith; sensing means for indicating the disposition of said portion of the stock relative to said Working position;

adjustable stop means for limiting the forward movement of the stock engaging means with the stock; and

means responsive to said sensing means for adjusting said stop means for controlling the permitted travel of the stock engaging means with said stock to cause the stock engaging means to be stopped by said stop means when said portion of the stock is accurately in said working position.

2. The apparatus for positioning stock of claim 1 wherein said sensing means comprises surface measuring means.

3. The apparatus for positioning stock of claim 1 wherein said sensing means comprises means responsive to the position of the leading end of the stock.

4. The apparatus for positioning stock of claim 1 wherein said sensing means comprises means responsive to the position of the leading end of the stock and said means responsive to said sensing means includes means for adjusting the position of the sensing means relative to the working position.

5. The apparatus for positioning stock of claim 1 wherein said sensing means comprises means responsive to the position of the leading end of the stock and said means responsive to said sensing means includes means for adjusting the position of the sensing means relative to the-working position, said means responsive to the sensing means being arranged to adjust each of said sensing means and stop means accurately equally.

6. Apparatus for positioning stock to extend an accurately preselected distance from a working position, compnsmg:

means for feeding stock forwardly through a working position to have a leading portion thereof move to adjacent a measured position spaced an accurate distance from said working position; means for engaging the stock and arranged to travel with the stock upon engagement therewith;

sensing means for indicating the disposition of said leading portion of the stock relative to said measured position;

adjustable stop means for limiting the forward movement of the clamp means with the stock; and means responsive to said sensing means for adjusting said stop means for controlling the permitted travel of the stock engaging means with said stock to cause the stock engaging means to be stopped by said stop means when said leading portion of the stock is accurately at said measured position.

7. The stock positioning apparatus of claim 6 wherein said sensing means includes a switch means rearwardly of said measured position for initiating operation of the stock engaging means sufiiciently prior to the time when said leading portion of the stock reaches said measured position to assure engagement of the engaging means with the stock prior to said time.

8. The stock positioning apparatus of claim 6 wherein said sensing means includes a switch means;

means for moving the switch means in correspondence with the movement of said stock engaging means; and

means for adjusting the position of said switch means relative to said leading portion of the stock and providing a signal to said stop adjusting means to adjust said stop accurately corresponding to the adjustment of the position of said switch means by said switch moving means, said switch means controlling the operation of said stop adjusting means.

9. The stock positioning apparatus of claim 6 wherein said sensing means includes a switch means;

a connector between said stock engaging means and said switch means for moving the switch means in correspondence with the movement of said stock engaging means; and

means for adjusting the position of said connector relative to said stock engaging means for repositioning said switch means relative to said leading portion of the stock and providing a signal to said stop adjusting means to adjust said stop accurately corresponding to the adjustment of the position of said switch means by said switch moving means, said switch means controlling the operation of said stop adjusting means.

10. The apparatus of claim 6 further including means for cutting the stock at said working position to provide a discrete piece of stock having an accurate length.

11. The apparatus of claim 6 further including stationary means for cutting the stock at said working position to provide a discrete piece of stock having an accurate length, said stock feeding means including means for taking-up the stock during the time the portion of the stock engaged by said stock engaging means is stopped by said stop means.

12. Apparatus for positioning stock to extend accurately in a preselected working position, comprising:

means for feeding stock to have a portion thereof move to said working position;

means for engaging the stock and arranged to travel with the stock upon engagement therewith;

means for sensing the movement of the surface of the stock and providing a signal corresponding to the disposition of said portion of the stock relative to said working position;

means responsive to said signal for adjusting said stop means for controlling the permitted travel of the stock engaging means With said stock to cause the stock engaging means to be stopped by said stop means when said portion of the stock is accurately in said working position.

13. The stock positioning apparatus of claim 12 wherein said signal providing means comprises a counter arranged to provide an electric pulse corresponding to each unit of length of travel of the stock past the sensing means.

14. The stock positioning apparatus of claim 12 wherein said sensing means comprises a counter having a surface measuring wheel arranged to ride on the surface of the stock as it travels therepast.

15. The stock positioning apparatus of claim 12 wherein said signal providing means comprises a counter arranged to provide an electric pulse corresponding to 16 each unit of length of travel of the stock past the sensing means and to provide an early warning signal after reaching a preselected count, and said signal responsive means includes means for initiating operation of the stock engaging means to engage the stock prior to the time said stock portion reaches said working position.

16. Apparatus for positioning stock to extend accurately in a preselected working position, comprising:

means for sensing the movement of the surface of the stock and providing a signal corresponding to the disposition of said portion of the stock relative to said working position; adjustable stop means for limiting the forward movement of the stock engaging means with the stock;

means responsive to said signal for adjusting said stop means for controlling the permitted travel of the stock engaging means with said stock to cause the stock engaging means to be stopped by said stop means when said portion of the stock is accurately in said working position, said sensing means including a switch arranged to be actuated upon a preselected travel of the stock engaging means to preclude further delivery of signals from said sensing means to said signal responsive means; and means operated by said actuated switch to adjust said stop means and provide signals to said signal responsive means, said signal responsive means further including means to prevent further adjustment of said stop means by said switch operated means when said stock portion reaches said working position.

17. The stock positioning apparatus of claim 16 wherein said means operated by said switch includes a power cylinder, a servo mechanism driven by said power cylinder, and said means for preventing further adjustment of the stop means includes a quick acting clutch connecting said power cylinder to said servo mechanism.

18. The stock positioning apparatus of claim 16 wherein said means operated by said switch includes a power cylinder, a servo mechanism driven by said power cylinder, and a linear transducer providing a pulse to said signal responsive means for each unit length of adjustment of said adjustable stop.

19. Apparatus for positioning stock to extend accurately in a preselected working position, comprising:

a fixed shoulder;

sensing means for indicating the disposition of said portion of the stock relative to said working position;

adjustable stop means on and movable forwardly from the stock engaging means to engage said fixed shoulder for limiting the forward movement of the stock engaging means with the stock; and

means responsive to said sensing means for adjusting said stop means for controlling the permitted travel of the stock engaging means with said stock to cause the stock engaging means to be stopped by engagement of said stop with said shoulder when said portion of the stock is accurately in said working position.

20. The stock positioning apparatus of claim 19 including a working tool and wherein said shoulder comprises a portion of said working tool.

No references cited.

WILLIAM W. DYER, 1a., Primary Examiner.

Claims

1. APPARATUS FOR POSITIONING STOCK TO EXTEND ACCURATELY IN A PRESELECTED WORKING POSITION, COMPRISING: MEANS FOR FEEDING STOCK TO HAVE A PORTION THEREOF MOVE TO ADJACENT SAID WORKING POSITION; MEANS FOR ENGAGING THE STOCK AND ARRANGED TO TRAVEL WITH THE STOCK UPON ENGAGEMENT THEREWITH; SENSING MEANS FOR INDICATING THE DISPOSITION OF SAID PORTION OF THE STOCK RELATIVE TO SAID WORKING POSITION; ADJUSTABLE STOP MEANS FOR LIMITING THE FORWARD MOVEMENT OF THE STOCK ENGAGING MEANS WITH THE STOCK; AND MEANS RESPONSIVE TO SAID SENSING MEANS FOR ADJUSTING SAID STOP MEANS FOR CONTROLLING THE PERMITTED TRAVEL OF THE STOCK ENGAGING MEANS WITH SAID STOCK TO CAUSE THE STOCK ENGAGING MEANS TO BE STOPPED BY SAID STOP MEANS WHEN SAID PORTION OF THE STOCK IS ACCURATELY IN SAID WORKING POSITION.