US3131431A

US3131431A - Machine for automatically pitch buttoning lens blanks

Info

Publication number: US3131431A
Application number: US176167A
Authority: US
Inventors: Thomas E Kolany; William E Soong; Robert E Miller
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-02-27
Filing date: 1962-02-27
Publication date: 1964-05-05
Anticipated expiration: 1981-05-05

Description

y 1964 T. E. KOLANY EI'AL 3,131,431

MACHINE FOR AUTOMATICALLY PITCH BUTTONING LENS BLANKS Filed Feb. 27, 1962 3 Sheets-Sheet 2 I INVENTORS.

THOMAS E. KOLANY 5 WILLIAM E. soom;

R. e. MILLER I BY I T j @rZM: w! Alb-1M.

ATTORNEY;

United States Patent C) 3,131,431 MACHlNE FGR AUTOMATICALLY PITCH BUTTONING LENS BLANKS Thomas E. Kolany, Elk Grove Village, William E. Soong, Chicago, and Robert E. Miller, Lombard, 111., assignors, by mesne assignments, to the United States at America as represented by the Secretary of the Army Filed Feb. 27, 1962, Ser. No. 176,167

3 Claims. (Cl. 18-26) This invention relates to the manufacture of optical lenses, and more particularly to a mechanism whereby a measured quantity of pitch may be applied to a lens blank. Such a measured quantity of pitch is commonly known as a pitch button and is utilized to fix the lens blank to a support during certain steps in the manufacture of the lens. The mechanism or machine by which the lens blank is pitch buttoned is herein designated as a itch buttoning machine.

Heretofore, it has been customary to fix the lens blank to a support either by pitch buttoning it or by providing in the support a recess fitted to receive it. In the case of pitch buttoning, the various steps involved have generally been performed manually. This involves considerable time. The present invention avoids this difficulty by the provision of a pitch buttoning machine which functions automatically to perform the various steps involved in pitch buttoning a lens blank.

As will appear, this patch buttoning machine has a four-position indexing table with a loading station, a pitch buttoning station, a cooling station, and an unloading station. At each station are two mold complements which work with a universal mold to make two pitch buttoned lens blanks simultaneously.

Above the pitch buttoning station, a pitch pot with thermostatically controlled heating for the pot, as well as the feeder tube area, is mounted on a vertical track to be lowered onto the mold complements by means of a pneumatic cylinder. Sequential operation is achieved through the use of timers and sequential microswitch operations. The amount of pitch is metered by means of a preadjusted pitch dispenser to deposit a desired amount of pitch on the lens blanks. The steel universal mold is cyclically heated by a high frequency induction heater and cooled by water admitted into the mold ducts at a predetermined time in the operating cycle.

The invention will be better understood from the following description when considered in connection with the accompanying drawings and its scope is indicated by the appended claims.

Referring to the drawings:

FIG. 1 is a side view of the pitch buttoning machine.

FIG. 2 is a somewhat schematic view indicating the relation between the various parts of the machine.

FIG. 3 is a top view of the machine,

FIG. 4 illustrates the structure of the universal mold,

P16. 5 indicates the construction of the mold complement, and

FIG. 6 is a block diagram calculated to facilitate an understanding of the various steps involved in the operation of the machine.

The pitch buttoning machine of the present invention includes an index table 19 which has holes 11 by means of which a plurality of mold complements 12 are fixed to it. Rotation of the table 19 on a bracket 13 is effected by air pressure. This is accomplished by a mechanical coupling, such as a pawl and ratchet, between the table and a piston which is movable in a cylinder 14. Air pressure for moving this piston is controlled by a conventional solenoid operated 4-way valve. As is well known, such a valve is rotatable to different positions for applying pressure to the opposite sides of the piston.

Fixed to a support 16 is a pitch pot 17 which is connected to a pitch dispenser 18 through solenoid operated valves 19 and 20 (FIG. 2) which are spring biased to their closed positions. Depending from the pitch pot 17 is a steel mold 21 (FIG. 4) which is connected through

check valves

22 and 23 to the pitch dispenser 18. Associated with the mold 21 are an induction heating coil 24 and mold temperature control means which include a solenoid operated water valve 25 and a timed relay 25 (F168. 2, 6). The valve 25 is spring biased to its closed position.

The support 16, together with the pitch pot and mold assembly, is moved up and down by the rod 26 of a piston which is movable in a cylinder 27 and has its motion controlled by a 4-way valve 28 as previously indicated. Downward travel of this piston is limited by lock nuts 29 which serve as an adjustable stop. At the upper limit of its travel it trips a switch 35 (FIG. 2) thereby deenergizing and closing the solenoid operated valve 26 and deenergizing the solenoid operated water valve 25 and actuating the piston in the rotary index table cylinder 14 as hereinafter described.

The pitch dispenser 18 includes a cylinder (FIG. 1) within which moves a piston 30 having oppositely extending

rods

31 and 32. The rod 31 is coupled to a piston which moves in an air cylinder 33 and has its movement controlled by a solenoid operated 4-way valve 34. The rod 32 at the end of its travel to the right, as viewed in FIG. 2, operates a limit switch 34' thereby reversing the stroke of the piston in the cylinder 33, actuating and opening the solenoid operated valve 21), actuating the timed relay 25 and simultaneously deenergizing the solenoid operated valve 19.

Associated with the support 16 is an extension 36 which, upon downward movement of the pitch pot and mold assembly, operates a switch 37 through which the piston in the cylinder 33 is actuated and the solenoid operated valve 19 is actuated to its open position.

Current is supplied to the heating coil 24 from a high frequency generator 38 through a timer switch 39. The coil 42 surrounds the mold 21 which is attached to the support 16 through guide rods 40 and springs 41 which serve to cushion the engagement of the mold with the mold complement 12. Cooling water is admitted through the solenoid operated valve 25 to an annular cavity 42 of the mold during a period determined by the timed relay 25'.

As shown more clearly in FIG. 5, the lens blank complement 12 includes a nylon support base 43, a solid cylinder 44 which supports the lens blank 46 and is surrounded by a compression spring 45, and a guide sleeve or hollow cylinder 47 which rests upon the spring 45 surrounds the lens blank 46 and has a flange 48 for steadying small blanks.

Compressed air for actuating the pistons in the cylinders 14, 2'7 and 33 is supplied through an inlet 49 (FIG. 2). A limit switch 50 is operated by cams 51 on the periphery of the index table 10 to energize the high frequency generator 28 and the solenoid operated 4-way valve 38 of the air cylinder 27 through which the pitch pot and mold assembly are raised and lowered.

The above described automatic pitch buttoning ma-.

chine is set up for operation manually. The procedure is as follows: Select mold complements 12 of a size to fit the lens blanks to be pitch buttoned and attach these mold complements securely in the holes 11 on the index table 10. Fill the pitch pot 17 with preheated pitch, adjust the thermostat of the heater, and turn on the heater coil timer switch 39. Place a lens blank on each mold complement so that they are arranged in radially disposed pairs on the index table it}. Operate the index switch 35 to bring the first pair of lens blanks under the dispenser nozzles of the mold 21. Operate the valve 28 to lower the universal mold 21 onto the lens blanks. Adjust the lock nuts 29 to avoid bottoming of the cushioning springs 41 on the mold. Return the mold to its up position. Actuate the high frequency heating timer switch 39. When the mold has reached an appropriate temperature, lower it onto the lens blanks. Operate the solenoids of the

valves

19 and 20 in unison with the dispenser cylinder switch 34 to fill and discharge the pitch dispenser 18. After the pitch has filled the mold, turn on the water fiow switch 25. When the pitch buttons have cooled sufficiently, turn off the water flow switch and rinse the mold. Check the sizes of the pitch buttons. If they are correct, adjust the limit switch 50 for automatic operation. If they are not correct, adjust the stroke of the pitch air cylinder 33 and repeat the above procedure until the desired buttoning is achieved.

Associated with the

switches

35, 50, 37 and 34' are the

connection reversing switches

52, 53, 54 (FIG. 6) the center terminals of which are connected to the opposite leads of a DC. source as indicated by the plus and minus signs. With the switch 52 in its illustrated upper position, the 4-way valve 15 is in a position to rotate the table 10 in a clockwise direction. With switch 52 in its lower closed position, the 4-way switch is in a position to retract the piston in the cylinder 14 for the next successive stroke.

With the switch 53 in its illustrated position, the heating coil timer switch is closed for a predetermined time and the 4-way valve 28 is rotated to a position such that the table 10 is lowered. With the switch 53 in its lower closed position, the switch 50 is disengaged from a cam 51 and the 4-way valve 28 is in a position to raise the table 10.

With the switch 54 in its illustrated closed position, the pitch valve 19 is open, the pitch valve 20 is closed, the water valve is closed, the timed relay 25' is deenergized and the 4-way valve 34 is in a position such that the pitch dispenser piston is driven to the right thereby buttoning the inner of the two lens blanks. In the upper closed position of the switch 54 the pitch valve 19 is closed, the switch 34 is closed thereby opening the pitch valve 20 and energizing the timed relay 25', and the 4-way valve 34 is a position such that the piston 30 of the pitch dispenser is driven to the left thereby buttoning the outer of the pair of lens blanks.

Cooling water is applied to the mold 21 for a time interval which is dependent on the setting of the timed relay 25.

Automatic operation of the pitch buttoning machine is initiated by operating the switch to the position indicated in FIG. 6. In this position, the pitch valve 20 is deenergized and closed, the water valve 25 is deenergized and closed, and the 4-way valve 15 is actuated to a position such that the index table It) is rotated in a clockwise direction.

As the table rotates, one of the cams 51 engages the switch 50 moving it to the position shown in FIG. 6. This energizes the heating coil timer switch 39 and initiates heating of the mold 21 by the coil 24-. After a predetermined time, the switch 39 deenergizes the coil 24 and, at the same time, actuates the 4-way valve 28 to a position such that the mold 21 and support 16 are lowered upon the lens blanks 46.

As a spring loaded mold 21 is seated on the lens blanks 46 the slight compression of the springs 45, due to piston rod overtravel, trips the switch 37 to the position shown in FIG. 6. This completes electrical circuits whereby the pitch valve 19 is opened and the 4-way valve 34 is operated to a position such that the piston 30 of the pitch dispenser 18 moves to the right thereby buttoning the inside lens blank by depositing on it a given volume ofpitch.

As the piston 39 nears the end of its stroke to the right, the extension 32 trips the switch 34', thereby energizing and opening the pitch valve 29, energizing the timed relay 25, deenergizing and closing the pitch valve 1?, and operating the 4-W21Y valve 34 to a position such that the travel of the piston 34} is reversed. Thereupon the pitch dispenser 13 discharges the same amount of pitch on the outside lens blank.

The cams 51 are so disposed that rotation of the table 10 is arrested at a point where a pair of lens blanks are alined with the openings in the mold 21. After each pair of lens blanks is pitch buttoned, cooling water is applied to them for a time interval which is predetermined by the setting of the timed relay 25. This completes the automatic operating cycle of the buttoning machine.

We claim:

1. In a machine for pitch buttoning optical lens blanks,

, the combination of an index table having successive stations at which are a mold complement and a circuit control member, said mold complement including a lens blank and support means therefor, said support means including a solid cylinder underlying said lens blank, a guide sleeve surrounding said lens blank and at least a portion of said support means, said support means and said guide sleeve each having an outwardly extending flange, and a compression spring positioned between said flanges, a support movable in a direction parallel with the axis of said table, an assembly fixed to said support and extending over said table, said assembly including a pitch pot containing pitch compound and a truncated cone mold communicatively connected therewith, a coil for heating said mold, a heating coil timer switch, means for raising and lowering said support, and a limit switch operated by said control member to close said heating coil timer switch and to complete a first connection of said support moving means, said heating coil timer switch controlling said support and lowering means, said guide sleeve in its normal position extending above the uppermost common contact surface between it and said blank, so that when said assembly is moved downwardly against said blank and its support means, the guide sleeve will retract to a subsequently formed uppermost common contact surface and enable the pitch compound to flow precisely to the extreme edge of the lens blank upper surface.

2. In a machine for pitch buttoning optical lens blanks, the combination of an index table having successive stations at each of which are a pair of mold complements and a circuit control member, each of said mold complements including a lens blank and support means therefor, said support means including a solid cylinder underlying said lens blank, a guide sleeve surrounding said lens blank and at least a portion of said support means, said support means and said guide sleeve each having an outwardly extending flange, and a compression spring positioned between said flanges, a support movable with respect to said table, an assembly fixed to said support and extending over said table, said assembly including a pitch pot containing pitch compound and a pair of truncated cone molds communicatively connected with said pitch pot through a pair of solenoid operated valves and a pitch dispenser, said pitch dispenser having a piston between the outlets of said valves, means for reciprocating said piston, a limit switch, means operated by engagement to said control member with said limit switch to lower said assembly, means operated by said assembly at the end of its travel to open a first of said valves and actuate said reciprocating means in one direction to discharge a measure of pitch in one of said molds, and means operated by said reciprocating means near the end of its travel successively to close said first valve, to open the second of said valves, and to reverse the travel or" said reciprocating means and discharge a measure of pitch in the other of said molds, each guide sleeve in its normal position extending above the uppermost common contact surface between it and its blank, so that when said assembly is moved downward against each blank and its support means, each guide sleeve will retract to a subsequently formed uppermost common contact surface and enable the pitch compound to flow precisely to the extreme edge of each lens blank upper surface.

3. In a machine for pitch buttoning optical lens blanks, the combination of an index table having successive stations at each of which are a pair of mold complements and a circuit control member, each of said mold complements including a lens blank and support means therefor, said support means including a solid cylinder underlying said lens blank, a guide sleeve surrounding said lens blank and at least a portion of said support means, said support means and said guide sleeve each having an outwardly extending flange, and a compression spring positioned between said flanges, a support movable with respect to said table, an assembly fixed to said support and extending over said table, said assembly including a pitch pot containing pitch compound and a pair of truncated cone molds communicatively connected with said pitch pot through a pair of solenoid operated valves and a pitch dispenser, said pitch dispenser having a piston between the outlets of said valves, a solenoid operated valve for controlling the flow of cooling water to said molds, a timed relay for determining the time during which water valve is open, means for reciprocating said piston, a limit switch, means operated by engagement of said control member with said limit switch to lower said assembly,

means operated by said assembly at the end of its travel to open a first of said valves and actuate said reciprocating means in one direction to discharge a measure of pitch in One of said molds, and means operated by said reciprocating means near the end of its travel successively to close said first valve, to open the second of said valves, to reverse the travel of said reciprocating means and discharge a measure of pitch in the other of said molds and to energize said timed relay for opening said water valve, each guide sleeve in its normal position extending above the uppermost common contact surface between it and its blank, so that when said assembly is moved downward against each blank and its support means, each guide sleeve will retract to a subsequently formed uppermost common contact surface and enable the pitch compound to flow precisely to the extreme edge of each lens blank upper surface.

References fitted in the file of this patent UNITED STATES PATENTS 2,217,335 Eden Oct. 8, 1940 2,263,302 Johnson Nov. 18, 1941 2,317,597 Ford et a1. Apr. 27, 1943 2,608,721 Heinzelman Sept. 2, 1952 2,774,289 Wanders May 8, 1956 2,903,041 Jones et al Sept. 8, 1959 3,043,711 Beale July 10, 1962 FOREIGN PATENTS 740,400 Great Britain Nov. 9, 1955

Claims

1. IN A MACHINE FOR PITCH BUTTONING OPTICAL LENS BLANKS, THE COMBINATION OF AN INDEX TABLE HAVING SUCCESSIVE STATIONS AT WHICH ARE A MOLD COMPLEMENT AND A CIRCUIT CONTROL MEMBER, SAID MOLD COMPLEMENT INCLUDING A LENS BLANK AND SUPPORT MEANS THEREFOR, SAID SUPPORT MEANS INCLUDING A SOLID CYLINDER UNDERLYING SAID LENS BLANK, A GUIDE SLEEVE SURROUNDING SAID LENS BLANK AND AT LEAST A PORTION OF SAID SUPPORT MEANS, SAID SUPPORT MEANS AND SAID GUIDE SLEEVE EACH HAVING AN OUTWARDLY EXTENDING FLANGE, AND A COMPRESSION SPRING POSITIONED BETWEEN SAID FLANGES, A SUPPORT MOVABLE IN A DIRECTION PARALLEL WITH THE AXIS OF SAID TABLE, AN ASSEMBLY FIXED TO SAID SUPPORT AND EXTENDING OVER SAID TABLE, SAID ASSEMBLY INCLUDING A PITCH POT CONTAINING PITCH COMPOUND AND A TRUNCATED CONE MOLD COMMUNICATIVELY CONNECTED THEREWITH, A COIL FOR HEATING SAID MOLD, A HEATING COIL TIMER SWITCH, MEANS FOR RAISING AND LOWERING SAID SUPPORT, AND A LIMIT SWITCH OPERATED BY SAID CONTROL MEMBER TO CLOSE SAID HEATING COIL TIMER SWITCH AND TO COMPLETE A FIRST CONNECTION OF SAID SUPPORT MOVING MEANS, SAID HEATING COIL TIMER SWITCH CONTROLLING SAID SUPPORT AND LOWERING MEANS, SAID GUIDE SLEEVE IN ITS NORMAL POSITION EXTENDING ABOVE THE UPPERMOST COMMON CONTACT SURFACE BETWEEN IT AND SAID BLANK, SO THAT WHEN SAID ASSEMBLY IS MOVED DOWNWARDLY AGAINST SAID BLANK AND ITS SUPPORT MEANS, THE GUIDE SLEEVE WILL RETRACT TO A SUBSEQUENTLY FORMED UPPERMOST COMMON CONTACT SURFACE AND ENABLE THE PITCH COMPOUND TO FLOW PRECISELY TO THE EXTREME EDGE OF THE LENS BLANK UPPER SURFACE.