US2580061A

US2580061A - Hydraulic tapping device

Info

Publication number: US2580061A
Application number: US47861A
Authority: US
Inventors: Cecil E Adams
Original assignee: Denison Engineering Co
Current assignee: Denison Engineering Co
Priority date: 1948-09-04
Filing date: 1948-09-04
Publication date: 1951-12-25
Anticipated expiration: 1968-12-25

Description

-' Dec. 25, 1951 Filed Sept. 4, 1948 c. E. ADAMS HYDRAULIC TAPPING DEVICE FIG.

2 SHEETS-SHEET 1 JNVENTOR. GEO/L E. ADAMS Dec. 25, 1951 c. E. ADAMS HYDRAULIC TAPPING DEVICE 2' SHEETS-SHEET 2 Filed Sept. 4, 1948 FIG. 2

INVENTORK CEO/L E. ADAMS Patented Dec. 25, 1951 i HYDRAULIC TAPPING DEVICE Cecil E. Adam s, Columbus, Ohio, assignor to The Denison Engineering Company, Columbus, Ohio, a corporation of Ohio Application September 4, 1948, Serial No. 47,861

8 Claims.

This invention relates generally to hydraulic.

apparatus and is particularly directed to apparatus for tapping holes in metal, or, other material.

The invention also relates to hydraulic circuits and more particularly to a circuit of the type shown in my copending application Serial No. 682,974, new Patent No. 2,512,731, issued June 27, 1950, filed July 11, 1946, of which this application is a continuation-in-part An object of this invention is to provide .a hy-.

draulically actuated tapping machine, which will be automatic in its operation and which may be set to successively tap holes in objects automatically without undue attention bytheoperator.

An object of the invention also is to provide a hydraulic circuit for a tapping machine; the latter having a hydraulically actuated motor and an automatic control valve mechanism of the type shown in my Patent No. 2,561,766, which was.

granted July 24, 1951 on acopending application, Serial No. 600,736, filed June 21, 1945, whereby the hydraulic motor of the tappingv machine maybe caused to operate in one direction to eiiect the tapping of a hole and automatically reversed.

when the hole has been tapped to the proper depth, the reverse operation of the fluid motor withdrawing the tap for a succeeding tapping. op-

eration.

. A still further object of the invention is to provide a hydraulic system. for a tapping machine which system will be automatic in operationand.

have a control valve mechanism so constructed that in the event undue force is required to tap the hole the fluid motor which operates the tap will be reversed to withdraw the tap before breakage of the tap, or, other mechanism, might occur.

A'further object of the invention is to provide the hydraulic system mentioned in the preceding paragraph with additional control mechanism to effect the automatic operation of an indexing table forming a part of the tapping apparatus, the first control mechanism being operative to efiect the actuation of the index table at the conclusion of "a tapping operation, this table actuation taking place automatically and without attention by the operator.

Another object of the invention is to provide a tapping machine having a fluid motor and automatic valve mechanism for' controlling the operation thereof, the fluid motor having a lead screw coupled thereto, the lead screw cooperating with a stationary nut, or, other device, whereby rotation of the 'fiuid motor will cause similar rotation of the screw andlongitudinal movement thereof, the direction of rotation andlongitudinal move..

ment being dependent upon the direction of rotation of the fluid motor,v the valve mechanismbeing such that longitudinal movement of the" lead screw to a predetermined point will effect-the actuation of the valve mechanism to cause a reversal of the fluid motor thus effecting the reverse rotation of the lead screw and longitudinal movement thereof in the opposite direction.

Further objects and advantages of thepresent invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred form of embodi-- merit of the invention is clearly shown.

In the drawings:

Fig. 1 is a side elevational view, partly inver tical section, of a hydraulic tapping machine formed in accordance with the present invention. Fig. 2 is a diagrammatic view of the hydraulic system employed in the tapping machine shown in Fig. 1, parts of the mechanism forming the circuit being shown in section.

Referring more particularly to the drawings,.

the numeral 28 designates generally the tapping machine. This tapping machine includes a'press' frame 21 having base, uprightand head sections 22 to 24.respectively. The frame is provided in the lower portion at the rear with areservoir 25 v forming a part of the hydraulic system, which is designated generally by the numeral 26. forward portion, the base section of the frame has an index table supported thereby, the index table being indicated generally by the numeral 2'5.- The press frame and the index table are substantially identical with the press frame and index table set forth in the above mentioned copending application Serial No. 682,974.-

The head section 2d of the press frameis pro? vided with a fluid motor operated tapping mecha--' nism, indicated generally by the numeral 23, and

the control mechanism 35 by which the'operation of the entire apparatus is controlled, a second control mechanism 3i being provided-in connection with the index table to effect the control of such device.

Attention is directed to the hydraulic circuit shown in Fig. 2. It is believed that a completerelief valve 33, these elements being connected;

by a pipe line 34 toform a fluid pressure source;

a return line 35 extends from the relief valve to At its the reservoir 25 to conduct fluid to the latter when the pressure of the source increases beyond a predetermined amount. A pipe line 36 extends from the relief valve 33 to the inlet of the main control valve mechanism 30, the inlet being designated by the numeral 3'! and frequently hereinafter termed the pressure port.

The control valve mechanism has been illustrated and described in detail in both of the above mentioned copending applications and will only be described in a general manner herein sunflcient to afford an understanding of the present invention. The control valve mechanism includes upper and lower motor ports 38 and 40 arranged above and below the inlet port 31 and a pair of outlet ports 4| and 42 arranged above and below the motor ports 38 and 40. Between the inlet port 31 and the lower motor port 40, the valve mechanism is provided with another port 43, which is connected at all times with a bore 44 in which a manual control valve 46 is disposed. Between the lower motor port 43 and the lower exhaust port 42, the valve mechanism is provided with still another port 45, which will hereinafte be termed a control port.

The bore 44 receives a hollow spool constituting the control valve 46 which is employed to manually efiect the initiation of operation of the hydraulic system. It is also effective to discontinue the operation of the system when it is necessary, or, desirable. Valve 43 is biased toward a centered position by

coil springs

41 and 48 arranged at the upper and lower ends of the valve. The hollow interior of the spool valve serves to connect exhaust ports 4| and 42, the latter being connected by line 56 with the reservoir 25. The valve mechanism 36 is provided with a pair of valve elements 5| and 52, the former having an internal chamber 53 for the slidable reception of the valve element 52. Valve element 5| is isposed for sliding movement in the casing 54 of the valve mechanism and is pro- .vided with a plurality of rows of ports 55 to 6| inclusive, these ports being adapted to register with the ports 46 to 45 inclusive, in various positions of longitudinal movement of the valve element 5|. Valve element 5| is normally disposed in the position shown in Fig. 2, where it is yieldably held by a coil spring 62, the coil spring permitting the valve element to be moved either up or down from the position shown in Fig. 2. Movement of the valve element 5| is efiected through a shipper rod 63 secured to and depending from the lower end of the valve element.

The valve element 52 comprises a spool-like body having a groove 64 for establishing communication between certain sets of ports in the valve element 5|. The spool member 52 is normally maintained in the lowermost position in the chamber 53 by a coil spring 65, which permits upward movement of the element 52 in response to the introduction of fluid pressure into the chamber 53 at the lower end of the element 52. When the spool is moved in an upward direction, it will establish communication between a different set of ports than when it occupies the lowermost position shown. The purpose of establishing communication between certain set of ports at different times, will be set forth hereinafter.

With the parts of the mechanism in the position shown in Fig. 2, the valve element 52 directs fluid pressure from the source into the lower motor port 40 from which it will flow through line 66 to the fluid motor 61 forming a part of the tapping apparatus. The fluid exhausted from the motor, hows through line 68 to the upper motor port 38 from which it will flow through ports 66 to the interior of the valve element 5| above the element 52 and outwardly therefrom through ports 6| to the exhaust port 4|. This fluid then flows through line 50 to the reservoir 25. When fluid is flowing to the fluid motor 61 through the line 66 in the manner just described, the motor will be operated in a reverse direction, causing the lead screw 10, which is coupled with the motor to also revolve in a reverse direction, whereby a nut, or, similar element H which is fixed to the frame 2| will effect the longitudinal movement of the lead screw in an upward direction, this movement being transmitted throughan arm 12 to the shipper rod 63 after the lead screw has moved a sufficient distance to cause the outer end of the arm 12 to engage a collar 13 secured to the shipper rod. Arm 12 may be forked to extend around the shipper rod and be readily removable and it must have a swivel connection with the lead screw to allow rotation of the lat-'- ter. The final stage of upward movement of the lead screw 10 will cause the shipper rod 63 and valve element 5| to be moved upward until ports 51 no longer register with the lower port 40. When this registration is interrupted, fluid flow from the pressure source through line 66 will be discontinued.

Ports 58 are so arranged in valve element 5| that they will be brought into registration with port 43 in the body 54, simultaneously withthe interruption of communication between ports 51 and 40. The fluid pressure from the source will then be directed through ports 58 to port 43. When valve element 46 is in the position shown the fluid pressure from the source will be directed from the port 43 to the bore 44 from which it will flow into the port 38 thence through port 60, the chamber 53, ports 6| and 4| and be directed to-the reservoir 25 through line 56. At this time, the pump 32 will be unloaded and the tapping machine will be inoperative, the lead screw being in a retracted position ready for the next operation. As long as valve spool 46 remains in the position shown, the tapping mechanism will remain idle. When it is desired to effect a cycle of operation of the apparatus, the valve spool 46 is moved downwardly through the rotation of an eccentric pin 14 to a position wherein the head 15 at the upper end of the valve spool 46 will interrupt communication between bore 44 and port 38. The fluid from the pressure source will then be directed through line 16 to the secondary control valve mechanism 3|, which mechanism governs the operation of the index table. Attention is directed to the copending application Serial No. 682,974 for a detailed description of the operation of mechanism 3| and the index table, it being suflicient here to state that when fluid is introduced through line 16, the mechanism 3| will operate to cause the index table disc I1 to move, or, index a set member of degrees after which fluid flowing through line 16 will be directed through line 18 back to the control port 45 of the mechanism 30. This fluid will flow through ports 55 in element 5| to the chamber 53 at the lower end of valve element 52, the fluid pressure causing the element 52 to move upwardly in opposition to the force of spring 65 to a position wherein the groove 64 will establish communication between ports 59 and ports 60. Ports 59 are disposed at all times in communication with the inlet port 3'! and when connected by the groove 64 with ports .60, will direct fluid pressure from the source through ports 60 to the upper motor port 48 and line 68 to the motor 61. This fluid will cause the motor 61 to rotate in adirection which will in turn cause the lead screw to coact with the .nut .11 and move in a downward direction, this direction of movement of the lead screwand the direction of rotation of the motor 61 necessary to cause the same being hereinafter termed the forward direction.

When fluid is introduced to. motor t1 through line 63, fluid will be. exhausted from the motor 6'! through line 66. This fluid will flow through ports 40 and 51 to transverse ports 19. formed in the lower portion of the spool 52, these ports then being in registration with ports 51. Fluid entering through the ports 51 will flow upwardly through a central bore 823 and outwardly through a bore 8| in the top of valve element to the exhaust port M. Bore B8 is of such size that it will offer resistance to fluid flow therethrough causing an increase in pressure on the fluid in ports 19. This pressure will be transmitted downwardly through bore 82 to the chamber 53 atthe lower end of the valve spool 52. This pressure will serve to retain the valve spool 52, in the elevated position after fluid flow to line 16 is interrupted; it will be noted at this time that when the lead screw is retracted and valve element 5| is moved in an upward direction, ports 51 will be moved out of registration with port 453 and ports 58 will bemoved into registration with ports 43. Upon initial downward movement of the lead screw 1i! at the beginning of a cycle of the motor 61, a coil spring 62 will move the valve element St downwardly again,inte'rrupting cornmunication between the ports 53 and 43 and reestablishing communication between ports 51 and 40. Initial operation of the motor 6'! is possible due to the provision of a set of ports til-A in valve element 5|, which ports 51-A. register with the lower motor port 40, while ports 58 are registering with ports 43. The exhaust fluid during the initial operation of motor 61 may flow through line 66 to port 40 and through ports 51- A to ports 18, then after initial downward movement of the lead screw and corresponding movement of valve element 5|, communication will be established between ports 45) and 1a through the ports 51.

Forward rotation of motor 61- and downward movement of the lead screw 1ll will continue until fluid flow to the motor is interrupted, or, exhaust flow from the motor is discontinued. Either of these conditions will cause an interruption to the downward movement of the lead screw. It will be noted that relief valve 33 may be so set that in the event the resistance to movement on the part of the lead screw becomes sufliciently great, the relief valve will by-pass fluid from the pump 32 directly to the reservoir 25 and fluid pressure will cease to flow to the motor 61. When this fluid flow ceases, motor 61 will stop, discontinuing the flow of exhaust fluid through line 66. When this flow stops the fluid pressure in ports 19 and in the chamber below valve 52 will be dissipated permitting spring 65 to move valve 52 to its lowered position wherein the groove 64 will establish communication between the inlet port 31 and the lower motor port 40. Fluid pressure from the source may then flow directly to the motor 61 to cause reverse movement thereof effecting an upward movement of lead screw 10 and exhaust of fluid through line 68,

ports

38, 60, and GI, to the exhaust port 4!. When the lead screw has completed' its retractive movement, valve element 5| will be moved to a position to interrupt fluid flow-between ports 51 and 40, at which time r0- tationoi motor 61 will be discontinued. If .valve element occupies position shown in Fig. 2, the mechanism will come to rest; if, however, valve dd-has been locked in its lowered position fluid flowfrom the pressure source will be directed to the index table to cause it to perform an index-ing operation after which another cycle ofoperation "of motor 61 will be initiated. In the event, the fluid motor 61- is not stoppe in the manner set forth above, the arm 12 will engage a lower collar 84 fixed to the shipper rod 63 and move the shipper rod in a downward direction, also moving valve element 5! downward until'a groove 85 atthe upper end of the valve element immediately under the head 86 thereof, establishes communication between up per motor port '38 and exhaust port 4!. When this communication is established fluid pressure will'b'e directed to exhaust, rather, than through line 58 and fluid motor 61 will stop. The'flow of the exhaust fluid'will then be discontinued. Reverse rotation of the motor 61 will then be started in the same manner described above. It will thus be seen that a hydraulic systemhas been provided which will permit holes to be tapped to a predetermined depth, or, permit the tapping operation to be reversed and the tap withdrawn if a predetermined resistance to the tapping operation is encountered. The mechanism for performing the tapping operation may be varied in numerous ways, the mechanism shown beingselected for illustration only. In this mechanism, the drive shaft 81 of the fluid motor 61 has a connection with the lead screw which permits the latter to move longitudinally due to its reaction with the nut 1!, without interrupting the driving connection. It will be obvious that the lead screw and the nut 1| should be made readily removable so that lead screws provided with diflerent threads may be readily substituted therefor. The lower end of the lead screw is equipped with a suitable collet 88 to receive the tap essential in tapping operations.

I1.claim:

i. A hydraulicaily operated tapping machine comprising areversible fluid motor; a source of fluid pressure; control valve mechanism between fluid pressure source and said fluid motor, said mechanism having a valve member operative in a first position to cause rotation of said motor in a first direction and in a second position to cause rotation of said fluid motor in the opposite direction, said valve member being responsive to fluid pressure to move to said first position; fluid passage and orifice means for utilizing exhaust fluid from said fluid motor during operation in said flrst direction to maintain said valve member in said first position; a lead screw coupled for rotation with said fluid motor; a stationary nut cooperating with said lead screw to cause longitudinal movement thereof during rotation of said fluid motor; and motion transmitting means between said lead screw and said control valve mechanism, said motion transmitting means being operative to interrupt the flow of fluid pressure from said source to said fluid motor to discontinue opera tion thereof in said first direction when said lead 7 screw reaches a predetermined position in its longitudinal movement.

2. A hydraulically operated tapping machine comprising a source of fluid pressure; a reversible fluid motor; a control valve mechanism between said pressure source and said motor; tap-carrying means supported for longitudinal and rotary movement, and coupled to said fluid motor, rotation of said motor causing longitudinal and rotary movement of said tap-carrying means; a valve element in said control valve mechanism responsive to fluid pressure to move to a position to cause the rotation of said fluid motor in a certain direction; a second valve element in said control valve mechanism operative in one position to interrupt the rotation of said fluid motor in said certain direction; and motion transmitting means between said tap-carrying means and said second valve element, said motion transmitting means serving to move said second valve element to said one position when said tapcarrying means reaches a predetermined position during longitudinal movement thereof.

3. A hydraulically operated tapping machine comprising a source of fluid pressure; a reversible fluid motor; a control valve mechanism between said pressure source and said motor; tap-carrying means supported for longitudinal and rotary movement, and coupled to said fluid motor, rotation of said motor causing longitudinal and rotary movement of said tap-carrying means; a valve element in said control valve mechanism responsive to fluid pressure to continue the rotation of said fluid motor after such rotation is initiated; the application of fluid pressure to said valve element ceasing upon the interruption of rotation of said fluid motor; and means for moving said valve element to a position to cause rotation of said fluid motor in the direction to reverse the movement of said tap-carrying means when the application of fluid pressure to said valve element ceases.

4. Hydraulically operated tapping apparatus comprising a source of fluid pressure including an adjustable relief valve; a reversible fluid motor; control valve mechanism between said pressure source and said motor, said mechanism having a valve element responsive to the application of fluidpressure depending upon the operation of said motor to continue motor operation in a predetermined direction; means for moving said valve element to a position to cause operation of said motor in the opposite direction when the application of fluid pressure to said valve element is interrupted; tapping means actuated by said. fluid motor, predetermined resistance to operation of said tapping means causing the;

operation of said relief valve to interrupt the flow of fluid pressure to said fluid motor and discontinue the operation thereof, the cessation of motor operation interrupting the application of fluid pressure to said valve element.

5. A hydraulically operated tapping machine comprising a source of fluid pressure; a reversible fluid motor; a lead screw coupled to said fluid motor for rotation therewith; a stationary member cooperating with said lead screw to cause longitudinal movement thereof upon rotation of said motor; an index table having a fluid motor; control valve mechanism between said fluid pressure source and said fluid motors, said mechanism having valve elements responsive in part to valve 'mechanism being operative to actuate the confluid pressure to initiate the operation of the first-mentioned fluid motor; motion transmitting means between said lead screw and said control mechanism, said motion-transmitting trol valve mechanism at a predetermined stage of movement of the lead screw to direct fluid pressure from said source to said second-mentioned fluid motor to cause the operation ofv said I index table, and means operated by said secondmentioned fluid motor substantially at the conclusion of an indexing operation of the index table to apply fluid pressure to the valve elements of said control valve mechanism to initiate a cycle of operation of said first-mentioned fluid motor.

6. Hydraulically operated tapping apparatus comprising a source of fluid pressure including an adjustable relief valve; a reversible fluid motor; control valve mechanism between said pressure source and said motor; reversing valve means in said mechanism operative when said relief valve by-passes fluid from said pressure source to reverse the direction of operation of said fluid motor; and tapping means actuated by said fluid motor, predetermined resistance to operation of said tapping means causing the operation of said relief valve.

7. Hydraulically operated tapping apparatus comprising a source of fluid pressure; a reversible fluid motor; valve mechanism between said pres-- sure source and said motor; a reversing valve in said mechanism serving in one position to cause said fluid motor to operate in one direction; means operative when said fluid pressure source reaches a predetermined pressure to move said reversing valve to another position to cause said fluid motor to operate in a reverse direction; and tapping means actuated by said fluid motor, resistance to operation of said tapping means causing the pressure of said source to increase.

8. Hydraulically operated tapping apparatus comprising a source of fl-uid pressure; a reversible fluid motor; control valve mechanism between said pressure source and said motor; a reversing valve in said mechanism, said valve serving in a first position to cause said fluid motor to operate in one direction; means in said control valve mechanism operative when said fluid pressure source reaches a predetermined pressure to move said reversing valve to a second position to cause said fluid motor to operate in a reverse direction; tapping means actuated by said fluid motor, re sistance to operation of said tapping means causing the pressure of said source to increase; and means actuated by said fluid motor after the same has operated a predetermined extent in said one direction to cause said reversing valve to move to said second position in the event the pressure of said source of fluid pressure does not increase to said predetermined pressure.

CECIL E. ADAMS.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS