US2711674A

US2711674A - Two-station broaching machine

Info

Publication number: US2711674A
Application number: US443555A
Authority: US
Inventors: Jr Olney J Abbott
Original assignee: COLONIAL BROACH CO
Current assignee: COLONIAL BROACH CO
Priority date: 1954-07-15
Filing date: 1954-07-15
Publication date: 1955-06-28
Anticipated expiration: 1972-06-28

Description

June .28, 1955 o. J. ABBOTT, JR 2,711,674

TWO-STATION BROACHING MACHINE Filed July 15, 1954 8 Sheets-Sheet l INVENTOR.

June 28, 1955 Q J T, JR 2,711,674

' TWO-STATION BROACHING MACHINE Filed July 15, 1954 8 Sheets-Sheet 2 (Li-m ((G-P-I I BY June 28, 1955 Q, ABBQTT, JR I 2,711,674

TWO-STATION BROACHING MACHINE 7 Filed July 15, 1954 8 Sheets-Sheet 3 IN V EN TOR. 0/7162 0, filzpff, fr.

Torn/1714s June 28, 1955 Q ABBOTT, JR 2,711,674

TWO-STATION BROACHING MACHINE Filed July 15, 1954 8 Sheets-Sheet 4 IN V EN TOR. 072m??? \7. #2242 2? J 1 June 28, 1955 o. J. ABBOTT, JR 2,711,674

TWO-STATION BROACHING MACHINE Filed July 15, 1954 8 Sheets-Sheet 5 IN V EN TOR. 71 17/935072? J3".

June 28, 1955 O. J. ABBOTT, JR

TWO-STATION BROACHING MACHINE 8 Sheets-Sheet 6 Filed July 15, 1954 June 28, 1955 o. J. ABBOTT, JR

TWO-STATION BROACHING MACHINE 8 Sheets-Sheet 7 Filed July 15, l954 NQP INVENTOR- 017m? J 771%075 J77 June 28, 1955 o. J. ABBOTT, JR 2,711,674

TWO-STATION BROACHING MACHINE Filed July 15, 1954 8 Sheets-Sheet 8 United States Patent r 1 2,711,674 TWO-STATION BROACHING MACHINE Olney J. Abbott, Jr., Detroit, Mich, assignor to Colonial Breach Company, Warren Township, Macomb County, MiclL, a corporation of Delaware Application July 15, 1954, Serial No. 443,555 Claims. (Cl. 90-33) This invention relates to breaching machines and more particularly to an improved two-station pull-down breaching machine.

In breaching operations it is quiteoften necessary to use an extremely long broach or a plurality of shorter breaches in order to remove the necessary amount of metal to complete the breaching operation. In many instances these breaches are relatively large in diameter and are extremely cumbersome to handle. Also, the use of extremely long broaches requires breaching machines which are very large and expensive to manufacture and presents breach maintenance and care problems. Furthermore, many factories or plants do not have sufiicient head space to permit the use of a breaching machine which accommodates an extremely long breach in the order of perhaps eight or ten feet. In the past when it has been desired to pass more than one breach through an opening with a pull-down breaching operation, it has been necessary to manually change the broaches after each cycle. This is a time consuming and expensive operation and greatly reduces the production efficiency.

It is an object of this invention to provide a breaching machine which accommodates a plurality of breaches and which is constructed and arranged so that each of the broaches can perform its operation on a workpiece without being removed from the machine and in a completely automatic manner so that the operator need not touch the machine except to remove the finished workpiece therefrom and load a new workpiece to be breached therein.

It is a further object of this invention to provide a pull-down breaching machine of the aforementioned type, in which at least a pair of breach-handling chucks adapted to carry broaches are reciprocably supported on the machine and are adapted to be automatically moved into alignment with a breach-pulling chuck disposed on the eppesite side of a workpiece supporting fixture therefrom so that the single station pulling chuck coacts with the plurality of breach-handling chucks for the breaching of a single workpiece.

It is a still further object of this invention to provide a breaching machine of the aforementioned type in which a workpiece supporting structure is shuttled into and out of operative position in timed relationship with the movement of the'breach-handling and pulling chucks.

It is a still further object of this invention to provide a breaching machine of the aforementioned type, which is efiicient and rapid in operation, durable in construction, completely automatic, easy to set up and adjust, relativel simple and inexpensive in construction.

These and other objects of this invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, in which:

Figure 1 is a fragmentary perspective view of the breaching machine of this invention;

Fig. 2 is a front elevational view of the structure illustrated in Figure 1;

Fig. 3 is a view partially in section and partially in elevation, of the structure illustrated in Fig. 2, taken along the line 22 thereof;

Fig. 4 is a side elevational view of the structure illustrated in Figure l;

Fig. 5 is a sectional view of the structure illustrated in Fig. 3, taken along the line 55 thereof;

Fig. 6 is a diagrammatic view of the hydraulic circuit of the machine of this invention; and

2,711,674 Patented June 28, 1955 Figs. 7a and 7b, when placed together, are a diagrammatic view of the electrical circuit of the machine of this invention.

Referring now to the drawing, it will be seen that the breaching machine includes stationary supporting structure 9, in cluding a base portion 11 and a vertical column 13. -A horizontal platform member 15 is supported on the structure 9 and projects outwardly therefrom. The platform 15 has ways 17 adjacent the opposite sides edges thereof and a fixture 19 is slidably supported on the platform 15 and guided for movement inwardly and outwardly relative to the vertical column by the ways 17. The fixture 19 supports a workpiece 20 having an opening therein to be breached. A pair of hydraulic piston and cylinder units 21 and 23 are supported on the platform 15 and, as can be best seen in Fig. 6, each of these units includes a cylinder 25 having a bore fitting piston 27 therein, to which a piston rod 29 is connected. The piston rods 29 are connected in any suitable manner to the fixture 19, so that actuation of the units will move the fixture inwardly or outwardly on the platform.

A breach-handling shuttle 31 is reciprocably supported on the vertical column 13 for reciprocation laterally thereof. In this connection, the shuttle includes a rearwardly projecting slide portion 33, which slidably engages a platelike bearing surface 35 on the front face of the vertical column. The bottom of the shuttle 31 is guided for reciprocating movement in a way 37 on the front of the vertical column above the platform 15. A pair of side-by-side breach-handling chuck slides 39 and 41 are reciprocably supported on the shuttle 31 for vertical movement toward and away from the platform 15. The slides 39 and 41 are reciprocably supported in suitable ways 43 on the shuttle 31. Handling chuck brackets 45 and 47 are adjustably connected with the slides 39 and 41 respectively and each of the brackets 45 and 47 supports a breach-handling chuck 49 and 51 respectively. The breach-handling chucks are of a suitable spring-loaded release type such-as illustrated in United States Patent No. 2,539,981, issued to Benedict Welte on January 30, 1951, entitled Broaching Machine. Each of the breachhandling chucks 49 and 51 is illustrated as supporting broaches 53 and 55 respectively.

Piston and cylinder units 57 and 59, for independently actuating the chuck slides, are supported on the vertical column behind the slides 39 and 41 respectively.

As can be best seen in Figs. 5 and 6, each of the piston and cylinder units 57 and 59 includes a cylinder 61 having a bore fitting piston 63 therein and a piston rod 65 is connected with piston 63 and extends beyond cylinder 61 with the free end thereof being connected at 67 to the adjacent handling chuck slide 39 or 4'1. A fluid conduit 69 communicates with the top of piston and cylinder unit 57 and a conduit 71 communicates with the piston and cylinder unit on the lower side of the piston 63. Conduit 73 communicates with the upper end of piston and cylinder unit 59, while conduit '75 communicates with the lower end of the unit. The conduits are adapted to be connected with a suitable source of fluid under pressure, as will be hereinafter described, so that independent movement of the pistons 63 can be obtaineTso as to move the adjacent handling chucks individually and independently relative to each other. A pair of vertically extending rods 77 are supported on the vertical column by suitable bracket means 79, on opposite sides of each breach-handling chuck. Adjustably connected with each rod is a breach trip or release member 81, which is adapted to engage the adjacent breach-handling chuck at a predetermined point in its downward movement toward the fixture to cause the chuck to release the breach that it is carrying. Also supporting each pair of rods 77, below the release members 81, is a bracket 82, which supports a breach guide 63 which is adapted to prevent swinging of the broach during the shuttling operation. As can be best seen in Fig. 3, the broach guide includes laterally adjustable elements 85, which can be adjusted radially of the broach to properly engage the periphery thereof and guide the same.

A broach-pulling chuck 87 is supported below the fixture 19 in an adapter 89, which in turn is connected with a bracket member 90. Bracket 90 is keyed to a main ram 91, having a movable cylinder and a bore fitting piston 97. The ram and bracket are slidably supported on the machine base for vertical movement toward and away from the fixture. The bore fitting piston 97 within the cylinder 95 includes a hollow vertically extending tubular portion 99, which extends upwardly beyond the upper end of thee ylinder and is connected to a fitting or housing member 100, which in turn is suitably supported in the stationary structure of the machine. The

' hollow tube portion 99 is provided with apertures 101 in the peripheral wall thereof just above the bore fitting portion of the piston 97 so as to communicate the interior of the tube portion 99 with the portion of the cylinder 95 above the piston. A tube 103 extends through the tube member 99 and the piston 97, so that the lower end thereof communicates with the portion of cylinder 95 below the piston, while the upper end thereof is disposed in the housing member and communicates with conduit 105 thorugh a passage 107 in the member 100. The upper end of tubular member 99 is open and communicates with a conduit 109 through a passageway 111 in the member 100. When it is desired to move the broach-pulling chuck downwardly fluid is directed through conduit 105, passage 107 and the tube 103 to the bottom of the cylinder 95 so that fluid pressure between the bottom of the piston 97 and the bottom wall of the cylinder will force the cylinder downwardly. At the same time fluid in the upper portion of the cylinder will flow through the apertures 101 in the tubular member 99 up through the tubular member and through passage 111 in member 100 and out through conduit 109. When it is desired to raise the cylinder 95 and thus the broach-pulling chuck, fluid under pressure is admitted through conduit 109 While the fluid flows from the ram through conduit 105 in just the reverse manner as previously described. The broach-pulling chuck 87 may be of any suitable type and may be similar to the broach-handling chuck. Suitable means are pro vided for actuating the chuck to cause it to release from the broach at a predetermined point in its upward stroke, in substantially the same manner as with the handling chucks.

in order to shift the broach-handling chuck shuttle 31 laterally of the machine base to position either handling chuck in vertical alignment with the pulling chuck, a piston and cylinde unit 121 is provided and interconnected with the machine vertical column and the shuttle adjacent the upper end of the latter. As can be best seen in Figs. 3 and 6, the piston and cylinder unit 121 includes a fixed cylinder 123 which is suitably connected with the vertical column of the machine. A bore fitting piston 125 is disposed within the cylinder 121 and carries

piston rods

127 and 129 which extend through opposite ends of the cylinder and are suitably connected to the shuttle. Stop or

abutment members

131 and 133 are carried by the

piston rods

127 and 129 respectively, and are engageable with the stationary machine supporting structure to limit the lateral movement of the shuttle. The stop or

abutment members

131 and 133 are adjustable so that when the shuttle is in either of its shifted positions, that is fully to the right or fully to the left, the stops will engage a portion of the machine stationary supporting structure and prevent the shuttle from moving beyond a point of alignment with the broach-pulling chuck disposed on the opposite side of the fixture. The piston and cylinder unit 121 is connected with a suitable t fluid power source, as will be hereinafter described, so as to shift the shuttle between its first and second positions to align either of the handling chucks with the pulling chuck.

Referring now to Fig. 6, which is a diagrammatic illustration of the hydraulic circuit of the machine, the various components are illustrated in the normal inoperative machine position preparatory to starting an automatic cycle of operation. In this position both the handling chuck pistons 63 are in their uppermost position, the ram cylinder 95 is in its uppermost position, the fixture is in its out position, and the shuttle is shifted to the right so as to position the left hand handling chuck in alignment with the broach-pulling chuck. The main hydraulic pump which is a variable delivery type pump, and the auxiliary hydraulic pump 152, along with other pumps such as the coolant motor, chip conveyor motor and the like, are energized to circulate fluid under pressure through the system and are connected to a suitable fluid reservoir or tank 153. At the outset, and as will hereinafter appear in conjunction with the description of the electrical circuit, solenoid S1 of a solenoidoperated, pilot-controlled, four-way valve 154 is energized so that fluid flowing from auxiliary pump 152 to the valve through conduit 155 will flow under pressure through conduit 157 to actuate pistons 27 and move the fixture 19 inwardly and thus carry the workpiece to a breaching position. Fluid in the opposite end of the cylinders 25 will flow through conduit 159 and valve 154 to tank 153 through conduit 161. When the fixture is moved to its inner position limit switch LS2 is actuated and the limit switch LS2 likewise is actuated in the opposite direction when the fixture moves to its fully out position. fter the fixture has moved to its innermost position solenoid S2 of solenoid-operated, pilot-controlled, four-Way valve 163 is energized so that fluid flowing from auxiliary pump 152 through conduit 155 will flow through valve 163, through conduit 69, to the upper end of the cylinder 61 of the piston and cylinder unit 57, so as to move the piston 63 thereof downwardly. Fluid in the lower end of cylinder 61 will flow through conduit 71 back through a counterbalance valve 165, whose only function is to maintain piston 63 in its position when the machine is idling, through conduit 167, valve 163 and conduit 161 to tank. When the handling chuck 49, connected with piston rod 65 of unit 57, moves downwardly it carries the broach downwardly into engagement with the pulling chuck 87 and is released from engagement with the chuck. When the piston rod 65 moves downwardly limit switches LS3 and LS5 are tipped. Thereafter solenoid S4 which is connected with the main pump 150, is energized. The energization of solenoid S4 in turn operates a control pilot valve causing the pump to shift the main rotor in the pump so that fluid will flow through conduit 105 and into the main ram causing the same to move downwardly on the first broaching stroke and pull the broach through the workpiece. The main pump 150 is normally in a neutral position wherein it does not pump oil through either conduit 105 or conduit 109. However, when a solenoid is energized, the pilot control valve in the pump shifts the rotor to cause fluid to flow through one conduit and permit fluid to return to tank through the other conduit. Thus, when the cylinder moves downwardly fluid flows through conduit 109 back to the pump. When the ram begins its downward movement limit switch LS8 is tripped and When the ram reaches its lowermost position it actuates limit switch LS7.

it should at this time be pointed out that the machine is provided with a prefill valve 167 which is connected with auxiliary pump 152 through conduit 169 and which has conduits 1'70 and 171 leading therefrom which are interconnected with conduits 109 and 10.5 respectively. Likewise a counterbalance valve 173 is provided in conduit, 109 to maintain the ram in position when the machine is idle. However, to more positively assure the ram being in its uppermost position the prefill valve 167 is provided and if when the machine is idle, the ram moves downwardly due to leakage in the system or the like, so as to move out of engagement with limit switch LS8, solenoid S11 is actuated and the ram will be moved back to its raised position and held in such position. Solenoid S11, however, is inoperative during the normal cycling operation of the machine.

When the ram reaches its lowermost position solenoid S4 is de-energized and ram movement is stopped, and solenoid S5 of four-way valve 154 is energized so that fluid flows from the pump 152 through valve 154: and conduit 159 to move the fixture to its out position. At the end of this stroke solenoid S5 is de-energized and solenoid S6 is energized, causing the main pump 155 to deliver fluid under pressure through conduit 199 and thus raise the ram to its raised position at which time switch LS7 is actuated. The breach is thus moved back into engagement with the handling chuck and is released by the pulling chuck. At the end of this stroke solenoid S6 is de-energized and solenoid S7 of four-way valve 163 is energized, causing fluid to flow under pressure from pump 152 through conduit 155, conduit 170, counterbalance valve 165 and conduit 71, to cause the left hand handling cylinder to move to its uppermost position carrying the breach with it, which broach has been released by the breach-pulling chuck, as previously described. When the handling cylinder reaches its uppermost position switch LS3 is actuated.

At the end of the upward stroke or" the left hand handling cylinder piston 63, solenoid S7 is de-energized, which stops the movement of the piston, and solenoid S9 of the four-way valve 177 is energized so that fluid will flow from pump 152, through conduit 155, fourway valve 177, conduit 1'79, into a flow-control valve 151 and from the valve 181 through a conduit 183 to the right hand end of the cylinder 123, so as to move the piston 125 toward the left, which in turn will move the shuttle 31 to the left to bring the right hand handling chuck 51 into vertical alignment with the pulling chuck. it will be noted that the valve 151 is of the cam operated type and has a plunger 185 projecting therefrom, which is adapted to be actuated by a cam 187 illustrated diagrammatically in Fig. 6 as being mounted on the piston rod 129, although actually the cam is mounted on the shuttle itself. As the cam 187 engages the plunger 135, the flow of fluid through conduit 183 is decreased and fluid entering the valve 181 through conduit 179 is returned to tank through conduit Such an arrangement slows down the movement of the shuttle as it approaches its left hand position and prevents the shuttle stop 133 from engaging the machine stationary structure with too much force. Fluid in the opposite end of the cylinder 123 flows to tank through conduit 139, a flowcontrol valve 1% identical with flow-control valve 181, conduit 19]., four-way valve 177 and conduit 161. At the end of its stroke limit switch LS1 is actuated and solenoid S9 is de-energized, while solenoid S1 of four- Way valve 154 is energized. The energization of the solenoid 51 causes fluid to flow from pump 1152, through four-way valve 154, and conduit 157 into the fixture cylinders 21 and 23, so as to cause the pistons 27 thereof to move inwardly and thus carry the fixture 19 inwardly to position the workpiece in the proper position for the broaching operation, by the broach carried in the right hand handling cylinder.

At the end of its inward movement limit switch LS2 is actuated and solenoid S3 of four-way valve 192 is energized so that fluid flowing from pump 152 will flow through conduits 155 and 169 into valve 192 and from valve 192 fluid under pressure flows through conduit 193 into the upper end of piston and cylinder unit 59 to cause the piston thereof to move downwardly and thus move the right hand broach-handling chuck downwardly so as to move the lower end of the breach through the workpiece and into engagement with the breach-pulling chuck. Downward movement trips-limit switches LS4 and LS6 and solenoid S3 is de-energized, while solenoid S4 is energized for starting the ram down on its second broaching stroke, in the same manner as previously described.

t the end of the downward movement of the ram solenoid S4 is deenergized and solenoid S5 of the fourway valve 154 is energized for shuttling the fixture 19 to its out position, as previously described. When the fixture 19 is in its out position and has actuated limit switch LS2, solenoid S5 is de-energized and solenoid S6 energized so that fluid flowing from the main pump will move the ram back to its uppermost position, as previously described.

At the beginning of this stroke limit switch LS7 is tripped and at the end of this stroke limit switch LS3 is actuated and solenoid S6 is de-energized, while solenoid S8 of four-way valve 192 is energized so as to shift four-way valve 192, thus causing fluid to flow from pump 152 through conduits 155 and 169 into valve 192 and thence through conduit 194, foot valve 195, which is identical with foot valve previously described, conduit 196, into the lower end of piston and cylinder unit 59, so as to raise the right hand handling chuck and carry the broach to its uppermost position with the lower end thereof disposed above fixture 19. When the right hand chuck reaches its uppermost position limit switches LS4 and LS6 are actuated, solenoid S8 is de-energized and solenoid Slti of four-way valve 177 is energized so that fluid flowing from pump 152 will flow through conduit 155, valve 177, conduit 191, flow control valve 199 and conduit 189, into the left hand end of cylinder 123 so as to move the piston 125 to the right and return the shuttle 31 to its right hand starting position. It will be noted that flow-control valve likewise has a plunger 197 engageable by a cam 198 carried by the shuttle and actuatable as the shuttle approaches its right hand position so as to by-pass fluid through a conduit 199 to tank and slow up the motion of the shuttle so that it will not strike the stop 131 with too much force. When the shuttle reaches its right hand position limit switch LS1 is again actuated and solenoid S10 is tie-energized and the automatic cycle of the machine is completed. It will thus be appreciated that the entire cycle is automatic and is hydraulically and electrically controlled.

The specific electrical control circuit that operates to coordinate and control the various components of the broaching machine is shown in Figures 7a and 7b; the two figures being joined together along the line aa to provide a complete diagram. Certain minor electrical elements, unimportant to the invention or circuit, has e been deleted, such as overload relays connected in the motor lines, fuses, light receptacles, and the like. It will also be apparent that in the description of the electrical circuit energization of solenoids S1 to $10, which are electrically interlocked with limit switches LS1 to L819, act to control the four-way valves of the hydraulic system and hence the various steps in the cycling of the machine, as previously described. Inasmuch as the circuit functions to permit not only automatic cycling of the machine, but also separate movement of the individual machine elements for setting the machine up in operation, the explanation and description of the circuit diagram will be described in detail only for the automatic cycling operation of the machine.

It should be noted here that the illustrated circuit diagram depicts the circuit conditions of the system before any power has been applied thereto and when the broaching machine is in its initial starting condition; that is, with the handling cylinders in their up position, fixture '19 in its out position, and handling shuttle 31 in its right hand position, and the main ram in its up position.

Power is supplied to the electrical control circuit across input lines L1, L2, and L3 from a suitable electrical power source; preferably a three-phase alternating current source. To permit isolation of the circuit from the power source in the event that the circuit is to remain tie-energized for any length of time, a main disconnect switch 290 is interposed in the lines. Connected across input lines L1, L2, and L3, through line switches 262, 204 and 2% respectively, are hydraulic motor 159, auxiliary hydraulic motor 152, and the fluid coolant and chip conveyor motors 2&5 and 297; the latter of which are connected in parallel and to the input lines through switch 206. As will hereinafter be described, actuation of switches 2&2, 204, and 2% to their closed positions is controlled by a set of contactors 291, 2433, and 295, respectively, which are situated in the main control circuit such that the motors are energized only upon cyclic operation of the machine. The main control circuit is energized through a pair of power lines 2553 and 21$ and a step-down transformer 212, both of which are connected across input lines L1 and L3. The output of transformer 212 is fed through

power lines

214 and 216.

Situated in the circuit for the purpose of selecting either automatic or individual component operation is a manually operated selector switch having a plurality of contacts A, B, C, N. Depending upon the opened or closed condition of these switches, which is determined by the position of selector arm 219, the machine will operate either automatically for performing a complete broaching operation or in a manner whereby fixture 19, left hand handling cylinder 57, right hand handling cylinder 59, ram 91, or handling shuttle 31, will move, individually, in a forward and reverse direction. The latter arrangement is such that initial tool set-up of the machine is facilitated, but it is not thought necessary herein to describe the electrical circuit and operation for each of such individual movements, so that only the automatic cycle will be described in detail.

Assume that a workpiece 20 is positioned in fixture 19, a breach is held by each of the handling chucks and the machine is otherwise in condition for a broaching operation. Then, selector arm 219 is turned to Auto position to close switch contacts A and B. Initial initiation of the ci cuit is controlled by start switch 220. De pressing the start button momentarily closes switch 223 to energize contactors 291, 263 and 2&5 through a circuit comprising line 214, the contactors, start switch 226, a stop switch 221 and line 216. Contactor 2S1 upon being energized will close its associated line switches 202 for completing the power circuit to main hydraulic motor 15%; and further, close its associated switch 2ll11 for providing a holding circuit therefor, around start switch 224).

Similarly, contactors 203 and 265 will close their respecl tive line switches 264, 2% for starting auxiliary hydraulic motor 152, coolant motor 265, and chip conveyor motor 297. Also, each of the contactors 233 and 295 is provided with a holding switch 2l31, 2054, respectively, connected in parallel with start switch 220.

Closing of the start switch 229 further energizes control relays CR4, CR3 and CR9 and first pass pilot light 222 which is connected across control relay CR4, the latter providing a visual indication that the machine is in preparation for undergoing a breaching operation with the left hand positioned breach. The energizing circuit for control relay CR4 is from line 214, through relay CR4, limit switch LS1, which engages its upper contact due to the handling shuttle being in its right position, line 223, through switches 2215 and 221 to line 216. The energizing circuit for control relay CR8 is from line 214 through relay CR3, limit switches LS9 and LS3, back to line 216; while the energization circuit for relay CR9 is from line 214 through limit switches. LSltl and LS4, and back to line 216. Limit switches LSE and L510 are associated with the handling shuttle 31 and act as interlocks for opening these relay circuits in the event a broach fails to pick up. Limit switches LS3 and LS4 are closed due to the fact that the left hand handling chuck and right hand handling chuck are in their up positions, respectively.

4 As described thus far, each or" these elements is energized during Auto cycle or the other specific operations of the machine with the exception, however, that the control arm 219 will be moved in different positions in accordance with the particular operation desired and hence, contacts AN of switch 219 will be changed accordingly.

The actual movement of the broaching machine is initiated by depressing the Forward switch 224 which serves to energize control relays CR1 and CR1. Control relay CR6 closes its associated switch TtCRO for providing a holding circuit around switch 224 and is energized through a circuit including line 214, contact A of switch 218, through a pair of emergency stop switches 227, line 223, and back through switches 221i and 221 to line 216. Control relay CR1 is actuated through a circuit including line 214, control relay CR1, normally closed switch .iCRS, normally closed switch 1CR2, normally closed switch lCRiS, and switches 1CR9, 1CR8 to line 223 and back to the source. Switches 1CR9 and 1CR8 are normally open but due to relays CR8 and CR9 being energized, these associated switches are closed. Upon energization of control relay CR1, solenoid S1 is energized through normally closed switches 1CR13 and 1CR7 and through switches 1CR4 and llCRl which are closed upon energization of relays CR1 and CR4. As such, fixture 19 is driven to its in position by pistons and cylinder units 21 and 23, for placing the workpiece in broaching position. This shuttle movement of the fixture trips limit switch LS2 to its up position for energizing control relay CR6 through a circuit extending between lines 214 and 223.

Control relay CR6 is inter-related with the solenoid S2 by an associated switch 1CR6 such that energization of control relay thus serves to energize solenoid S2 through normally closed switch lCRld. and switches 1CR6, ZCPA, and ZCRl, the latter being closed by the energization of their respective relays. Upon solenoid S2 becoming energized fluid flows to the left hand handling cylinder for driving the handling chuck 49 downward carrying the breach 53. In so doing, limit switches LS3 and LS5 are tripped for de-energizing control relay CR8 and energizing control relay CR1 3. This action will then energize control relay CRltl, which in turn will open normally closed contact iCRld in the circuit of solenoid S2 for de-energizing the circuit and stopping the downward mo tion of the handling cylinder. Meanwhile CRll will be energized b" the closing of its switch 'ZCRlll. The energizing of control relay CRlll will complete a circuit through solenoid 84 from line 208, through switches iCRll to line 21% back to its source such that fiuid flow is controlled to the ram 91 for drawing the ram downwardly on a breaching stroke. It will be noted that solenoid S4 is controlled through the circuit comprising lines 203 and 2th which are connected directly to the input lines L1 and L2. As the ram begins its downward movement, limit switch LS3 is tripped for energizing relay CRiS for reasons which will hereinafter become apparent.

Upon reaching the bottom of its stroke, ram 91 trips limit switch LS7 which energizes control relay CR13, for

opening switch 3CR13 in the circuit of control relay C1211. The de-energization of control relay CRll opens switches 1CR11 and ZCRTT. in the power circuit of solenoid S4 such that the fluid flow to the ram cylinder is stopped and hence, the ram is stopped. Control relay CR13 upon de-energization also de-energizes switch lCRlS in the control circuit of solenoid S1 for de-energizing this solenoid; and closes its associated normally open switch SCRis for energizing solenoid S5 through switches 3CR6 and 3CRtl. Solenoid S5 in turn controls the flow of fluid to the fixture shuttle cylinders 25 to cause the fixture to shuttle to its out position, which action in turn trips limit switch LS2 in closing relation with control relay CR7.

Tripping of limit switch LS2 de-energizes control relay 9: CR6 and further, de-energizes solenoid S due to the opening of switch 3CR6 associated with the control relay CR6. This action operates to stop the fixture movement when it reaches its out position and further, serves to energize control relays CR7 and CR12; the latter being energized due to the closing of switch 3CR7 in its circuit, switches 2CR15 and 2CRO having been previously closed. As a result of energization of relay CR12, solenoid S6 is energized through the line 20%, switches 1CR12 and 2CR12 associated with control relay CR12 and line 210. Solenoid S6 controls the flow of fluid to the main ram cylinder for forcing the ram upwardly on a return stroke. The upward movement of ram 91 trips limit switch LS7 for de-energizing control relay CR13. Upon reaching the top of its stroke the ram trips limit switch LS which de-energizes control relays CR15 and CR12 due to the opening of switch 2CR15. Solenoid S6 is also de-energized due to the opening of switches 1CR12 and 2CR12 associated with the control relay CR12. Meanwhile control relay CR14 is energized through limit switch LS7, normally closed switch 3CR15, and switches 4CR7,

5CRO which are closed due to their associated relays being energized. Moreover, as relay CR15 is de-energized its normally closed switch 4CR15 becomes closed for energizing solenoid S7 which functions to direct the fluid flow to the left hand handling cylinder for driving the handling cylinder upwardly.

Upon moving upwardly, the left hand handling piston trips limit switch LS5 for de-energizing control relay CR10 and on further movement upwardly, trips limit switch LS3 for energizing control relay CR8. As a result, switch 4CR8 opens the power to solenoid S7, tie-energizing the same and stopping the fluid to the handling cylinder whereby the left hand handling cylinder is stopped. Upon energizing control relay CR8, its associated switch 5CR8, in the control circuit of solenoid S9, acts to close the power line through the solenoid S9 such that the line is completed from line 214, solenoid S9, closed switches 1CR14, 4CR9, switch 5CR3, switch 3CR5 and relay switch 4CR1 to line 216. This solenoid controls valve 177 for directing the fiuid flow to the handling shuttle 31 such that the handling shuttle moves toward the left for bringing the right hand positioned broach into cutting position. Upon beginning its motion the handling shuttle triggers limit switch LS1 for deenergizing control relay CR4 and energizing lock control relay CR2 through switch 4CR4. The latter serves to prepare the apparatus for a second pass operation wherein the right hand broach operates to additionally broach the workpiece.

Upon completing its motion, the handling shuttle 31 triggers limit switch LS1 to a closed position for energizing control relay CR5 and the second pass pilot light connected thereacross. Also, solenoid S9 is deenergized due to switch 3CR5 being opened. Opening of the solenoid S9 circuit serves to stop the shuttle movement. Energization of control relay CR5 also de-energizes the power circuit of control relay CR1 by opening its normally closed switch 1CR5. In turn, de-energization of control relay CR1 will serve to de-energize control relay CR7 by opening switch 3CR1 whereby control relay CR3 is energized by the closing of normally closed switch 6CR7 and control relay CR14 is de-energized due to the opening of its normally opened switch 4CR7. As such, the entire circuit is reset for the second pass whereby the right hand broach will be driven to perform its cutting operation.

In view of the fact that a considerable portion of the circuit is employed during the second pass operation, this operation will be described orilybriefly. The energization of relay CR3 and CR5 energizes solenoid S1, shuttling the fixture 19 in and thus tripping limit switch LS2 and energizing relay CR6. This action causes solenoid S3 to be energized, thus moving the right hand handling cylinder 59 downwardly, tripping limit switch LS4 and de-energizing relay CR9 at the top of the stroke, whereas limit switch LS6 is closed when the cylinder reaches the bottom of its stroke. This causes energization of relay CR10, CR11 and solenoid S4, as well as the de-energization of solenoid S3, thus stopping the downward movement of the handling cylinder and starting ram 91 down on the breaching stroke. Movement of the ram causes limit switch LS8 to be tripped and relay CRIS to be energized near the top of the ram 10 stroke, while limit switch LS7 is tripped and relay CRIS energized at the bottom of the stroke. Relay CR13 will tie-energize relay CR11, solenoid S4, stopping the ram movement, and also energizing solenoid S5, causing the fixture to shuttle to its out position. The movement 15 of the fixture 19 to its out position trips limit switch LS2, thus de-energizing relay CR6 and solenoid S5, so as to stop further fixture movement, while at the same time energizing relay CR7 and CR12 as well as solenoid S6, thus causing the ram to move upwardly. As the ram 20 starts its upward movement, relay CR13 is de-energized by the tripping of limit switch LS7 and when the ram reaches its upper position limit switch LS8 is tripped, thus de-energizing the relay CRIS, CR12 and solenoid S6, so as to stop the ram movement. Relay CR14 and solenoid S8 thus energize sending the right hand handling cylinder upwardly tripping limit switch LS6 and de-energizing relay CR10. When the handling cylinder reaches its uppermost position limit switch LS4 is tripped, energizing relays CR9 and solenoid S10, while de-ener- 3 gizing solenoid S3 and thereby stopping the handling cylinder movement. Thereafter solenoid S10 will cause the handling shuttle 31 to move to the right, tripping limit switch LS1 and de-energizing relay CR5 and the second pass pilot light, while energizing relay CR4 and the 35 first pass pilot light. Relay CR4 in turn de-energizes lock relays CR2, CR3, CR7, CR14 and solenoid S10, thus stopping the handling shuttle movement and ending the automatic cycle. If the workpiece 20 is unloaded from the fixture 19 and a new workpiece loaded thereon,

the cycle will be repated by the operator merely pressing the forward button.

It will thus be seen that the workpiece is automatically broached in a relatively simple and efiicient manner.

What is claimed is:

l. A broaching machine including stationary supporting structure, a workpiece supporting fixture supported on said structure for reciprocating in and out movement, means for reciprocating said fixture, a carriage supported on said structure on one side of said fixture for reciprocating movement transversely of said structure, means for reciprocating said carriage, at least two broach-handling chuck means supported on said carriage for reciprocating movement toward and away from said fixture, means for individually reciprocating said broach-handling chuck means, a single broach-pulling chuck means supported on said structure on the opposite side of said fixture for reciprocation toward and away from said fixture, means for reciprocating said broach-pulling chuck means, said broach-pulling chuck means being disposed in alignment with one of said handling chuck means when said carriage is in one position and in alignment with another of said handling chuck means when said carriage is in another position so as to coact with said handling chuck means to pull broaches through a workpiece supported on said fixture and return the broaches to their initial position after the breaching operation.

2. A broaching machine including stationary supporting structure, a workpiece supporting fixture supported on said structure for reciprocating movement, means for v reciprocating said fixture, a carriage supported on said structure on one side of said fixture for reciprocating movement transversely of said structure, means for reciprocating said carriage between a first position and a second position wherein said carriage is disposed transversely of its first position, a pair of side-by-side broachhandling chucks supported on said carriage for reciprocating movement toward and away from said fixture, means for individually reciprocating said broach-handling chuck means, a broach-pulling chuck supported on said structure on the opposite side of said fixture for reciprocation toward and away from said fixture, means for reciprocating said broach-pulling chuck, said broachpulling chuck being disposed in alignment with one of said handling chucks when said carriage is in said first position and with the other of said handling chucks when said carriage is in said second position, so that said pulling chuck can coact with each of said handling chucks to pull broaches through a workpiece supported on said fixture and return the same to their initial position after the breaching operation.

3. A broaching machine including stationary supporting structure, a workpiece supporting fixture supported on said structure for movement relative thereto, means for moving said fixture, a carriage supported on said structure on one side of said fixture for reciprocating movement transversely of said structure and generally parallel to said fixture, means for reciprocating said carriage, a pair of side-by-side broach-handling chucks supported on said carriage for reciprocating movement toward and away from said fixture, means for individually reciprocating said handling chucks, a broach-pulling chuck supported on said structure on the opposite side of said fixture for reciprocation toward and away from said fixture, means for reciprocating said pulling chuck, said broachpulling chuck being disposed in alignment with one of said handling chucks when said carriage is in one position and with the other of said handling chucks when said carriage is in another position, each of said handling chucks being adapted to carry a broach and move the same partially through a workpiece and into engagement with the pulling chuck which will pull the broach through the workpiece, means for actuating said broach-handling chuck reciprocating means to cause one of said handling chucks to move toward said fixture so that a broach carried thereby will be engaged by said broach-pulling chuck, means for actuating said broach-pulling chuck reciprocating means to cause said pulling chuck to move away from said fixture so as to pull said broach through the workpiece, means actuatable to release said first broach-handling chuck from a broach after it has moved a predetermined distance toward said fixture so that said broachpulling chuck can pull the broach completely through the workpiece and fixture, means for actuating said fixture, moving means to cause said fixture to move out of alignment with said broach-pulling chuck so that said broach-pulling chuck can move the broach upwardly without interference from the fixture or workpiece carried thereby, means for actuating said broach-pulling chuck reciprocating means to cause said chuck to move toward said fixture so as to move the broach into engagement with said first broach handling chuck, means for actuating said broach-handling chuck reciprocating means to cause said chuck to move away from said fixture so as to move said broach to the opposite side of said fixture, means actuatable to release said broach-pulling chuck from a broach after it has moved a predetermined distance toward said fixture to permit said handling chuck to move the broach beyond the fixture, means for actuating said fixture moving means to cause said fixture and a workpiece carried thereby to move back to the initial position after the broach has been moved to said opposite side, means for actuating said carriage reciprocating means to cause said carriage to move to a position in which said second broach-handling chuck is disposed in alignment with said broach-pulling chuck, means for actuating said broach-handling chuck reciprocating means to cause said second handling chuck to move toward said fixture so as to move a broach carried thereby at least partially beyond said fixture and into engagement with said broach-pulling chuck, means for actuating said broach reciprocating means to cause said chuck to move away from said fixture, means actuatable to release said second broach-handling chuck from its broach at a predetermined point of its movement toward said fixture so that said broach-pulling chuck can pull the broach to the opposite side of said fixture, means actuatable to thereafter actuate said fixture reciprocating means to cause said fixture to move out of alignment with said broachpulling chuck, means actuatable thereafter to cause said broach-pulling chuck reciprocating means to move said broach-pulling chuck toward said fixture to cause the broach to again engage said second broach-handling chuck, means actuatable thereafter to cause said handling chuck reciprocating means to move said second broachhandling chuck away from said fixture to return the broach carried thereby to a position on the opposite side of said fixture, means actuatable to release said broachpulling chuck from the broach so as to permit the broach to be pulled to the opposite side of said fixture, means actuatable thereafter to cause said fixture reciprocating means to return said fixture to its initial position, means actuatable thereafter to cause said carriage reciprocating means to move said carriage to its initial position, and means for synchronizing the operation of the various moving and reciprocating means to cause said machine to operate automatically, whereby the workpiece may then be removed after having been broached by two broaches.

4. A broaching machine including stationary supporting structure, a workpiece supporting fixture supported on said structure for reciprocating in and out movement, means for reciprocating said fixture, a carriage supported on said structure on one side of said fixture for reciproeating movement transversely of said structure, means for reciprocating said carriage, at least two broach-handling chuck means supported on said carriage for reciprocating movement toward and away from said fixture, means for individually reciprocating said broach-handling chuck means, a single broach-pulling chuck means supported on said structure on the opposite side of said fixture for reciprocation toward and away from said fixture, means for reciprocating said broach-pulling chuck means, said broach-pulling chuck means being disposed in alignment with one of said handling chuck means when said carriage is in one position and in alignment with another of said handling chuck means when said carriage is in another position so as to coact with said handling chuck means to pull broaches through a workpiece supported on said fixture, and means for synchronizing the operation of said reciprocating and moving means to cause said machine to operate automatically in a predetermined cycle.

5. A broaching machine including stationary supporting structure, a workpiece supporting fixture supported on said stationary structure for movement relative thereto, means for moving said fixture relative to said structure, carriage means supported on said structure on one side of said fixture for movement relative to said structure, means for moving said carriage means, at least two broach-handling chuck means supported on said carriage means for reciprocating movement toward and away from said fixture, means for individually reciprocating said broach-handling chuck means, a single broach-pulling chuck means supported on said structure on the opposite side of said fixture for reciprocation toward and away from said fixture, means for reciprocating said broachpulling chuck means, said broach-pulling chuck means being disposed in alignment with one of said handling chuck means when said carriage is in one position and in alignment with another of said handling chuck means when said carriage is in another position, so as to coact with said handling chuck means to pull broaches through a workpiece supported on said fixture and return the broaches to their initial position after the breaching operation.

No references cited.