US2067492A

US2067492A - Feeding apparatus

Info

Publication number: US2067492A
Application number: US709012A
Authority: US
Inventors: Kingsbury Edward Joslin
Original assignee: Individual
Current assignee: Individual
Priority date: 1934-01-30
Filing date: 1934-01-30
Publication date: 1937-01-12
Anticipated expiration: 1954-01-12

Description

Jan. 12, 1937. E. J. KINGSBURY FEEDING APPARATUS Filed Jan. 30, 1954 2 Sheets-Sheet 1 Jan. 12, 1937. E. J. KINGSBURY FEEDING APPARATUS Filed Jan. 30, 1954 2 Sheets-Sheet 2 55 5 6 :67, Zlnwntov Edward J $3 515 Patented Jan. 12, 1937 UNITED STATES PATENT OFFICE 22 Claims.

This invention relates to feeding apparatus in which a movable structure is given a motion back and forth with respect to a fixed structure, through the operation of fluid pressure means.

One of the features of the present invention is the provision of a change-over valve connected with feeding means through a plurality of conduits and serving! to admit fluid under pressure to one or another of these conduits, and operating in conjunction with automatic means whereby a full cycle of movement forward and back of the movable structure is produced with each movement of the change-over valve.

Another feature of the present invention is the provision of a change-over valve, and an automatic valve supplied with fluid and permitted to exhaust fluid through a plurality of conduits connecting it with the change-over valve, the automatic valve serving for effecting a full cycle of forward and back movements at each operation of the change-over valve for selecting and supplying a conduit with fluid under pressure.

Further features of the invention reside in the provision of such feeding and feed-control means, including a device operated when the movable structure attains the ends of its stroke in one direction to accomplish a movement of the automatic valve and therewith a reversal of the movement of the movable structure so that it completes its cycle.

With these and other objects in view, as will appear in the course of the following specification and claims, an illustrative form of practicing the invention is set out on the accompanying drawings, in which:

Figure 1 is a diagrammatic view of the elements, shown partly in section to illustrate the conduit connections employed.

Figure 1a is a detail showing the manner of operating a pump providing a source of fluid under pressure.

Figure 2 is a view on a larger scale, showing the fixed and movable structures in another relative position.

Figures 3, 4, 5 and. 6 are diagrammatic views showing the positions of the control elements at different stages of operation.

In these drawings, the feeding mechanism is illustrated as applied to a machine tool having a general housing H providing the fixed structure, and a reciprocable tool head T providing the movable structure. The head T is illustrated as having tool holders ID of drill chuck type thereon, being driven by the gears H within the tool head T from a splined spindle [2 which is operatively associated with a sleeve l3 driven by the pulley M which in turn is connected by a belt for drive from the tool motor TM mounted on the housing H. The spindle I 2 is carried by a sleeve I6 which may slide back and forth in the housing H and serves for supporting the tool head T in its various positions.

The tool head T is moved back and forth with 10 respect to the housing H by a piston rod which is connected thereto and has a piston 2| movable in the cylinder walls 22 of the housing H. The outer end of the cylinder is closed by a cap 23. The selective admission and with- 15 drawal of fluid at the ends of the cylinder effect the reciprocative movement of the tool head T in known manner.

In the illustrative form, the tool head T is to be given a rapid forward approach or tra- 0 verse movement until the tool is close to the work, then a slow feeding movement while the tool is operating on the work, and finally'a rapid reverse traverse or withdrawal movement. The illustrated structure corresponds to that shown 2 in my co-pending application Serial No. 705,607, filed January 6, 1934, and employs a downward projection 24 on the tool head T for engagement with the threaded end of a valve rod 25. This engagement is,adjustable and may be fixed by the clamping nuts 26. The valve rod has a reduced portion 21 within the housing H for controlling the flow of fluid into the right hand end of the cylinder, to regulate the rate of forward movement. A threaded sleeve 28 on the valve rod operates as a stop to limit the reverse traverse or withdrawal movement of the tool head T. A split sleeve 29 may be threaded to appropriate position on the valve rod and secured by a clamping screw 30; it operates to limit the forward movement of the tool head T by its engagement with the housing H.

The sump S contains a supply of liquid which is drawn upwardly in the feed pipe 35 by a gear pump 36 and thus is delivered to the outlet pipe 31 which leads to a change-over valve structure 38 having a rotatable plug or rotor 39. The change-over valve structure 38 is also provided with a discharge .pipe 40 leading back to the sump. A plurality of conduits ll, 42 lead from the change-over valve structure 38 to the tool units, and operate as manifolds connecting the change-over valve to all of the tool units. Only a single unit is illustrated, but it will be under- ,stood that any number of units may be con- An electric pump motor PM is provided with a shaft driving one of the elements of the diagrammatically shown clutch 45, the other ele- So long as less than a predetermined resistance is opposed to the flow of fluid from the gear pump, the spring 48 holds the elements of clutch engaged, and the motor PM drives the gear pump. As the pressure rises, more energy is demanded of the shaft 5| and a greater reaction is imposed upon the worm 46, until ultimately the worm tends to screw itself in the worm wheel 50, against the action of the spring 48 so that the clutch 45 releases and on the one hand protects the motor PM from overload, and on the other hand determines the maximum pressure which may be developed in conduit 37 by the action of the gear pump 36.

The lower part of the housing H is illustrated as containing an automatic piston valve of spool-like shape having the left hand head 55 provided with a port 56 communicating with a central passage 57 which is open at the right hand end of the valve. The central reduced portion 58 of the valve, in the position of Figure 4 establishes communication between the branch lla, of conduit 4| and the passage 59 leading directly to the righthand end of the cylinder 22 past the reduced portion 2? of the valve rod. The right hand end 60 of the piston valve has a port 6| which in the position of Figure 2 is in direct communication with a conduit 62 leading to the left hand end of the cylinder 22. The left hand end of the chamber with the conduit 4|. The right hand end of this space is in communication by a conduit 42a with the conduit 42. r

Within the housing H a conduit 59a branches from conduit 59 between the piston valve and the valve rod 25 and leads past a needle valve 63 and communicates by a port 64 with the right hand end of the cylinder 22, this path being employed for the restricted movement of fluid in accomplishing the slow working feed. Branched from the passage 55a between passage 59 and the needle valve 66 is a conduit 65 leading to the cylinder 22, which is closed againstthe flow of liquid from conduit 59a to the cylinder 22, by a ball check valve 66 which opens when the greater pressure is in, cylinder 22 to permit a return flow of fluid, independently of passage 64, back to passages 59a and 59. The needle valve 63 may be regulated to control the resistance ofiered to flow through the passage 64; and the energizing spring 61 of the check ball 66 may be regulated by the threaded plug 68. The upper lateral port 69 leading from the top of passage 59a. is closed externally by a relief valve as described in my aforesaid'co-pending application, and serves to permit release of gas from the conduits when -a liquid is employed as the fluid pressure ,medium, I

nected in likemanner to these manifold con- 1 and 2) of the tool head T, to engage a'crank dults;

16 which is pivoted to the housing H and connected by a draft link 16 with a detent 11 which is guided in the housing H and engages selectively, when in lowered position, with the right hand end of the piston valve, or with the groove 18a provided in the right hand head thereof. A spring 18 normally holds the crank I5 and detent ll with the latter in engaging position.

The operation of the illustrated device is as 7 follows:

When the change-over valve rotor 39 is in the position shown in Figure 3, thefluid under pressure is entering from conduit 31 and passing to conduit 42. Fluid in conduit 4| is permitted to pass to the discharge conduit 40.

The pressure in conduit 42 is therefore greater. Y

than that in conduit 4|. It is assumed in Figure 3 that the tool head T is being returned from a forward feeding movement, and hence that the piston 2| is being moved toward the right. conduit 42 through conduit end 42a to the right hand end of the piston valve, and is flowing through the central passage 51 thereof and through the port iii and conduit'62 to the left hand end of the cylinder 22. Fluid is also pass- For this purpose, fluid is passing from a ing from. the right hand end of the cylinder 22 I through

passages

64 and 65 to passages 59a and 59, past thereduced central section of the piston valve, through" conduits 4| a and 4|, back to the change-over valve for discharge. The split stop sleeve 29 on valve rod 25 has initially been holding the detent 'i'l raised, but the piston .valve is in its extreme left hand position and is being urged further in this direction by the pressure from conduit 42a against its right hand end, so that no movement thereof can occur.

As the tool head T moves toward the right, the split stop sleeve 29 leaves the crank 15 and the detent 11 drops and engages the right hand end of the piston valve. During the course'of this reverse traverse or withdrawal movement of the tool head T, the reduced portion 21 of the valve rod 25 opens passage 59, to the right hand end of the cylinder 22, and fluid may likewise move to discharge by this route. Ultimately,

change is that fluid under pressure flows from conduit 31 to conduit 4|, while the fluid in conduit 42 is now permitted to exhaust to the discharge pipe 40.

The presence of fluid under, pressure in conduit 4| causes liquid to flow along the path by 21 of the valve rod 25, to the right handend of the cylinder 22 directly, causing a rapid movement of the piston 2| and therewith 'o fflthe tool head T in a forward direction (toward the left in the figures). The pressure of fli ifidjbuild ing up in passage 4| 12 against the left hand end of the piston valve,can produce no effect, as this valve is now latched by the detent At the end of the distance of rapid forward traverse, as determined by the position of the valve rod 25 with respect to the extension 24 of the tool head T, the reduced portion 21 is withdrawn from passage 51, and this direct path-of flow is closed as shown in Fig. 2. Fluid must now move through the conduit 59a, past the needle valve 63 and through passage 64 to the right hand end of cylinder 22. The rate of flow is regulated by the needle valve 63, since only a predetermined maximum of pressure can be exerted from the gear pump 36 owing to the aforesaid action of the clutch member 45 and spring 48. Hence a slow forward cutting feed is attained. During the entire forward stroke, the check valve 66 is held closed by the pressure behind it. The fluid in the left hand end of cylinder 22 moves back through conduit 62, port 6|,'the central passage of the piston valve, and

conduits

42a and 42 back to the discharge.

When the tool head T completes its forward movement, the split stop sleeve 29 again engages the crank 15 and lifts the detent 17. At the same time, the stop sleeve 29 engages the housing H and brings the tool head T to a standstill at a predetermined distance of forward stroke.

The release of detent permits the pressure from conduit 4| tooperate through'conduit 4|b to move the piston valve to its right hand position (Fig. 5). The central space of the automatic piston valve now establishes communica tion from conduit 4|a with conduit 62, so that fluid under pressure flows into the left hand end of the cylinder 22 and causes a reverse traverse or withdrawal movement again until limited by the stop 28 as described above. During this return movement, the fluid in the right hand .end of cylinder 22 escapes through

passages

64, 65, 59a. and 59 in the same manner as before, but moves from the passage 59 through port 56 to the central passage of the piston valve 7 and thus to

conduits

42a and 42 back to the change-over valve structure 38 and is thus discharged. During the initial part of the movement, the detent ll is held raised by the split stop sleeve 29, but this has no effect as the pressure of conduit 4| is being exerted at the left hand end of the piston valve. After a short movement, the split sleeve 29 permits the detent T! to be lowered again, this time engaging in the groove 18a in the right hand head of the piston valve. When the stop 28 engages the housing H, the tool head T comes to a standstill and remains in this position until the changeover valve 38 is again operated, through an angle of to the position 0 of Figure 6. The connections thus accomplished at the changeover valve are identical with those of Figure 3. Fluid is supplied to the conduit 42 under pressure and moves to the right hand .end of the piston valve, through the central passage of the piston valve and by conduit 59 to the right hand end of the cylinder 22 to effect a further forward feeding movement, firstly at a rapid rate and then at a slow rate in the manner described above. The escape of fluid from the left hand end of the cylinder 22- occurs through conduit 62, past the reduced central portion of the piston valve and by conduits Ma and 4| to the change-over valve structure 38 and thus to the discharge. The pressure against the right hand end of the automatic piston valve does not cause a leftward movement of this valve, owing to the engagement of the detent I! therewith. At the end of the forward stroke, however, the

split stop sleeve 29 again lifts the detent l1, and the automatic piston valve moves back to the position of Fig. 3.

It will be noted that each reversal of connection of the source of supply and discharge, at the change-over valve structure 38, with respect to the conduits 4| and 42, produces automatically a full cycle of movement of the tool head T, forwardly at a. rapid and then a slow rate, and a complete withdrawal to the original position. This original position is then maintained until the change-over valve structure is again operated. Two successive movements of 90 each of the particular change-over valve structure shown results in two complete cycles and forward and reverse traverse movements of the tool head T.

The tool unit comprised of the housing H and the tool head T, with associated parts, is con nected with the source of supply, the sump, and the change-over valve by a plurality of conduits, two being used in the illustrative form, and a complete cycle of movement is accomplished for each operation of the change-over valve so that there is a remote control of the movements at the tool unit with respect to the initiation of each cycle. Since the pressure in the conduit 4| or 42 is controlled only at the change-over valve, any number of units may be connected thereto, and each will perform its operations independently of the others, and regardless of the operation of the others so long as a suificient supply of fluid at a desired pressure is being afforded. It is not necessary to move the change-over valve to accomplish the withdrawal of any unit, as this is controlled by the automatic piston valve in the particular unit. Hence the system adapts itself to arrangements of the type described in my aforesaid co-pending application, with a plurality of such units which start together, but complete their work in different times.

In operation, further, a certain period of time elapses while the automatic piston valve is moving from one position to another, and while the flow of the fluid pressure medium is adapting itself to the new condition. Hence, the split stop sleeve 29 engages the housing H and produces a definite dwell of the tool at the end of its forward movement which is useful in drilling to an exact depth and for facing operations. The stop is mechanical, and hence no variation of the depth occurs.

It is obvious that the invention is not limited to the form of device shown, but that it may be applied within many ways of the scope of the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent, is:-

1. A device of the type described comprising fixed and movable structures, fluid-pressureoperated feeding means for moving said movable structure back and forth, a source of fluid under pressure, a plurality of conduits, a change-over valve for connecting one said conduit to said source and another said conduit to a discharge and for reversing said connections, and thereby effecting the commencement of a cycle consisting of a forward and a reverse movement, a valve movable between end positions and omrating in' movable structure in forward and reverse directions, and detent means controlled by the movable structure for controlling movement of said valve from one end position to the other when said movable structure comes to the end of its movement in the forward direction whereby to cause the movement of said movable structure in the reverse direction, and also operating to prevent reversal of said valve except when said movable structure is at its forward position and thereby terminating each cycle with the movable structure in its withdrawn position.

2. A device of the type described comprising fixed and movable structures, fluid-pressureoperated feeding means for moving said movable structure back and forth, a source of fluid under pressure and conduit means therefrom, a valve operative in its end positions for selectively delivering fluid from said conduit means to said fluid pressure means, detent means for preventing movement of said valve from each end position to the other, said device including also conduit means by which fluid from the source may be employed for moving said valve successively from each said end position to the other when said detent means is released, and means operated by said movable structure at the ends of its movements for releasing said detent means and thereby procuring a movement of said valve and a backward movement of the movable structure.

3. A machine tool comprising a plurality of working units, each having a movable structure and each operating by repeated cycles consisting of a forward and a reverse movement, a'hydraulic motor for producing forward and reverse movements of said structure according to the direction of flow thereto, and a valve having a plurality of positions and controlled by the movable structure for operation from one of said positions to another at the end of the forward movement thereof for reversing the direction of flow of liquid to said motor independently of the valve movement in any other unit, a source of liquid under pressure, conduit means connecting said source and the said valves of all units, said controlled valves maintaining the direction of flow from the conduit means to the corresponding motors at the completion of the reverse movement whereby to terminate the cycle, and a valve for reversing the direction of flow in said conduit means to initiate a new cycle of operation of each said unit.

4. A machine tool comprising fixed and movable structures, fluid-pressure-operated feeding means for producing forward and reverse move-- ments of said movable structure, a source of fluid under pressure, a plurality of conduits, a change-over valve for connecting one said conduit to the source and another conduit to a discharge, an automatic valve movable between end positions in which it selectively controls the flow from said conduits to said feeding means and being pressed from one end position to another by the differential of fluid pressure in said conduits, a detent for preventing the movement of the automatic valve under such pressure differential, and means controlled by the movable structure for releasing the detent at the end of the forward movement of said movable structure.

5. A tool as in claim 4, in which said fixed structure and control means including positive stop structures which operate in conjunction with the automatic valve for causing a dwell of the movable structure at the end of its forward movement.

6. A tool as in claim 4, in which the automatic valve is formed as a piston exposed at its ends to the pressures in said two conduits.

7. A tool as in claim 4, in which the automatic valve is formed as a spool-like piston exposed at its ends to the pressures in said two conduits, and having its central space open to the pressure in one said conduit and selectively open to the said feeding means to supply and discharge is connected to said movable structure for movement relative to the fixed structure and operating to restrict the flow to the feeding means after a predetermined fractional forward movement, and in which said control means includes a stop member located on said valve rod and engageable with the fixed structure to limit the forward movement and operative to release said detent. V

10. A device of the type described comprising fixed and movable structures, fiuid-pressure-operated feeding means for moving said movable structure back and forth, a source of fluid under pressure, a plurality of conduits, a change-over valve for connecting said source to a selected conduit, and feed control means actuatable by the fluid flowing in the selected conduit and controlled by said movable structure for supplying fluid from said conduits to said feeding means and 'eflecting and terminating a cycle of movement thereof for each selecting movement of the change-over valve and including devices for preparing the feed control means to effect and terminate a succeeding cycle upon a further selecting movement of the change-over valve.

11. A device of the type described comprising fixed and movable structures, feeding means for moving said movable-structure back and forth, a source of fluid under pressure, a plurality of conduits, a change-over valve for connecting said source to a selected conduit, and feed control means actuated by the fluid flowing in the selected conduit and controlled by said movable structure for effecting a cycle of movement of said feeding means for each selecting movement of the change-over valve and including devices for preparing the feed control means to effect and terminate a succeeding cycle upon a further selecting movement of the change-over valve.

12. A device of the type described comprising fixed and movable structures, fluid-pressure-operated feeding means for moving said movable structure back and forth, a plurality of conduits communicating with said feeding means for supplying fluid under pressure to the same and for permitting its escape therefrom, means selectively operable for delivering fluid into one said conduit and permitting escape thereof from another said conduit, and feed control means actuatable by the fluid under pressure in any said conduit selected therefor and controlled by said movable structure for supplying fluid from said selected conduit to the feeding means for effecting a cycle of movement thereof for each selecting movement of said delivering means and for terminating each cycle with the movable structure in a predetermined initial position for the next cycle.

13. A device of the type described comprising fixed and movable structures, feeding means for moving the movable structure back and forth and including cycle-determining devices operating to effect a complete cycle of movement. of said movable structure at each energization of said feeding means and to detain the movable structure at the end of the cycle, each said cycle comprising a forward and a reverse movement, and directionally operative means for energizing said feeding means including a device for changing the direction of energization whereby to initiate successive cycles of movement.

14. A machine tool comprising a plurality of tool units each having a tool feeding means and means for detaining said tool in a withdrawn position, a single source for supplying energy for all saidfeeding means,'energy transmitting means connecting said source and all said feeding means, a single control device operative upon said transmitting means for simultaneously reversing the movement of all said feeding means to. initiate new cycles of movement from the withdrawn positions thereof, each said cycle comprising a forward and reverse movement and terminating with the feeding means at a withdrawn position, and devices included in each tool unit and controlled by the position of the corresponding tool for eifecting a reversal of the direction of movement of said tool by said feeding means at the advanced position thereof and held against further movement by the energy applied through said transmitting means whereby to maintain the feeding means in withdrawn position until the supply of energy is changed by movement of said single control device.

15. A machine tool comprising a tool unit having fixed and movable structures, feeding means for advancing and withdrawing the movable structure, a source for supplying energy to said feeding means, two reversing means each operative dependently upon the position of the other for controlling the direction of movement of the tool by said feeding means, and devices controlled by the position of the movable structure for actuating one said reversing means automatically at the end of a predetermined advancing movement, said one reversing means including means actuated by the supply of energy from the other said reversing means for maintaining said one reversing means to hold said movable structures in withdrawn position.

16. A device of the type described comprising fixed and movable structures, fluid-pressureoperated feeding means for moving said movable structure back and forth, a source of fluid under pressure, a plurality of conduits, a change-over valve for connecting said source to a selected conduit, and feed control means including reversing means actuatable by the fluid flowing in a selected conduit and also including detent means for preventing movement of the reversing means when first energized by fluid and released upon a predetermined movement of the movable structure so that the reversing means operates automatically for supplying fluid from said conduits to said feeding means and effecting and terminating a cycle of movement thereof for each selecting movement of the change-over valve.

17. A device of the class described comprising fixed and movable structures, feeding means' for moving said movable structure back and forth, a source of fluid under pressure, a plurality of conduits, a change-over valve for connecting said source to a selected conduit, and feed control means including reversing means actuatable in one direction by the fluid flowing in one conduit when selected and in another direction by fluid flowing in another conduit when selected and also including detent means for preventing movement of the reversing means when fluid is flrst caused to flow through the conduit to the reversing means and released upon a predetermined movement ofthe movable structure so that the feed control means operates automatically for effecting a cycle of movement of said feeding means for each selecting movement of the. change-over ,valve.

- structure back and forth, a plurality of conduits communicating with said feeding means for supplying fluid under pressure to the same and for permitting its escape therefrom, means selectively operable for delivering fluid into one said conduit and permitting escape thereof from another said conduit, and feed control means actuatable by the fluid under pressure in any said conduit selected therefor and controlled by said movable structure for supplying fluid from said selected conduit to the feeding means for effecting a cycle of movement thereof for each select ing movement of said delivering means and for terminating each cycle with the movable structure in a predetermined initial position for the next cycle, said feed control means including a member moved by the fluid under pressure in a direction determined by the conduit selected and also including detent means effective to prevent the movement of the movable member when a conduit is first selected and releasable by the movable structure as the latter approaches a forward limit of such movement whereby the movable member is actuated by the fluid flowing in the selected conduit for procuring a reverse operation of the feeding means.

19. A device of the type described comprising fixed and movable structures, feeding means for moving the movable structure back and forth, cycle controlling means including an automatic reversing device operating upon energization in either direction to effect a complete cycle of movement of said movable structure and to detain the movable structure at the end of the cycle, each said cycle comprising a forward and a reverse movement, detent means included in said cycle controlling means for detaining the reversing device during the forward movement and released upon the completion of the forward movement for permitting movement of the reversing device by' said energization to position for effecting the reverse movement, and a device for changing the direction of energization whereby to initiate successive cycles of movement.

20. A machine tool comprising a plurality of tool units each having a tool feeding means and means for detaining said tool in a Withdrawn position, a single source for supplying energy for all said feeding means, energy transmitting means connecting said source and all said feeding means, a single control device operative upon said transmitting means for simultaneously reversing the movement of all said feeding means to initiate new cycles of movement from the withdrawn positions thereof, each said cycle comprising a forward and reverse movement and terminating with the feeding means at a withdrawn position, and devices included in each tool unit and controlled by the position of the corresponding tool for effecting a reversal of the direction of movement of said tool by said feeding means at the advanced position thereof and v initial forward movement, each said detent means being constructed and arranged for release upon a predetermined forward movement of the corresponding tool so that the corresponding reversal device is moved and eflects the return of the tool to withdrawn position.

21. A machine tool comprising a tool unit having fixed and movable structures, feeding means for advancing and withdrawing the movable structure, a source of supplying energy to said feeding means, two reversing means each operative dependently upon the position of theiother for controlling the direction of movement of the tool by said feeding means, one said reversing means being actuated back and forth by energy from the source under control of the othefreversing means, and detent means for preventing said one reversing means from moving when first energized and being released by the move-' ment of the movable structure upon a prede termined advancement thereof.

22. A machine tool comprising a plurality of working units, each having a movable structure and each operating by repeated cycles consisting of a forward and a reverse movement, a hydraulic motor for producing forward and reverse movements of said structure according to the direction of flow thereto, a piston valve. and detent means'for holding the valve at either end position and released by the movable structure at the end of the forward movement, a source of liquid under pressure, conduit means connecting said source and the valves of all units and including two conduits each in free communication with all the piston valves for exerting an effort upon the valves when the corresponding conduit is charged, and a valve for selecting the conduit to be charged from the source, each said piston valve being constructed and arranged to effect a forward movement of the motor when any said conduit is charged whereby the detent is released and the piston valve is moved to its other end position, and to thereupon elfect a return movement and holding of the motor and movable structure. r

EDWARD J OSLIN KINGSBURY.