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Publication numberUS3603206 A
Publication typeGrant
Publication dateSep 7, 1971
Filing dateMar 16, 1970
Priority dateMar 16, 1970
Publication numberUS 3603206 A, US 3603206A, US-A-3603206, US3603206 A, US3603206A
InventorsRobert C Quackenbush
Original AssigneeQuackenbush Arthur B, Robert C Quackenbush
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Air-hydraulic linear feed device
US 3603206 A
Abstract  available in
Images(3)
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Claims  available in
Description  (OCR text may contain errors)

United States Patent [72] Inventor Robert C. Quackenbush Glendale, Calif. [211 App]. No. 19,663 [22] Filed Mar. 16, I970 [45] Patented SepL 7, I971 [73] Assignee Arthur B. Quackenbush Glendale, Calif. a part interest [54] AIR-HYDRAULIC LINEAR FEED DEVICE 15 Claims, 6 Drawing Figs. [52]- US. 91/61, 91/411 A, 60/6, 60/57 R, 92/12 [51] Int. Cl 'Flllb 7/16 [50] Field ofSoareh 1. 91/411 R, 411 A, 21, 61, 289;92/1 l, 12, 82, 143; 60/6, 57 R [56] References Cited UNITED STATES PATENTS 897,676 9/1908 Thompson 92/12 X 2,715,389 8/1955 Johnson 92/12 X 3,463,036 8/1969 O'Connor i 92/1 1 X Primary Examiner-Edgar W. Geoghegan AtmmeyMahoney, Hornbaker & Schick K) 44 52 42 54 4 50\ i I I H ABSTRACT: A main frame mounts an air cylinder acting through an hydraulic cylinder with the pistons of the two cylinders forwardly connected linearly moving a fluid motor, gear train and spindle forwardly in a feed stroke and rearwardly in a retraction stroke. The hydraulic cylinder controls the speed of the air cylinder during a fast portion of the feed stroke by the flow of hydraulic fluid through a major hydraulic fluid passageway from the forward to the rearward end of hydraulic cylinder, and during a slow portion of the feed stroke, a valve in the major hydraulic fluid passageway shunts the hydraulic fluid through an adjustable needle-valve-controlled, restricted hydraulic fluid passageway A constant supply of hydraulic fluid is always maintained in the major and restricted hydraulic fluid passageways by a resiliently urged plunger in a supply chamber connected to the major hydraulic fluid passageway. Return of hydraulic fluid to the forward end of the hydraulic cylinder during a fast retraction stroke is permitted directly forwardly through the hydraulic cylinder piston by a series of check valves. Fluid for rotatably driving the fluid motor is directed through a stationary fluid supply tube extending coaxial of the air and hydraulic cylinder pistons and a common piston rod of said pistons ream ardly telescopes the stationary fluid supply tube and fonns a movable fluid supply tube communicating with the fluid motor. A valve seat is formed between a radially relieved forward end of the stationary fluid supply tube and an internal annular shoulder of the movable fluid supply tube closing off the fluid supply to the fluid motor when the pistons are in fully retracted position and pennitting fluid flow when the pistons are moved forwardly commencing the feed strokev PATENTED s2? Hen SHEET 10F 3 INVEN'I'OR. .s ROBERTC. QUACKEN BUSH B YMAHONEY, HORNBA KER AND SCH/CK ATTORNEYS PATENTED SEP 7 I971 SHEET 2 0F 3 9. mm 8 S wv IN VENTO R. ROBERT C. QUACKENBUSH B YMA HONEY, HORNBA KER AND SCHICK ATTORNEYS PATENTEDSEP TIE?! 3.603.206

SHEET 3 0F 3 I m co 0 o m no 00 m I J tn 2 L t Z L g JO IN VENTOR. 9 N ROBERT C. OuA CKENBUSH BYMAHONEY, HORNBA KER AND SCH/CK ATTORNEYS AIR-HYDRAULIC LINEAR FEED DEVICE BACKGROUND OF THE INVENTION This invention relates to an air-hydraulic linear feed device of the type involving an air cylinder linearly moving a rotatable spindle in feed and retraction strokes controlled in such movement by an hydraulic cylinder, and more particularly to such a device having a unique simplified and improved hydraulic fluid flow control providing maximum overall feed control. Furthermore, the air-hydraulic linear feed device of the present invention includes a fluid motor aligned forwardly of and movable directly with the pistons of the air and hydraulic cylinders providing rotational drive for the spindle with an improved form of fluid supply automatically controlled by the piston movements.

Many and various fonns of linear feed devices have heretofore been provided for moving rotating spindle-mounted working tools, such as drills and the like, to and from workpieces upon which working operations are to be-performed in feed and retraction strokes. One of the major problems in the provision of such feed devices has been the manner of controlling the feed rate of the spindle and working tool thereon in order to feed the spindle and tool swiftly to the workpiece location and then, at a predetermined time, slowly feeding the spindle and tool into the workpiece during the intended working operation. Although hydraulic cylinders alone have been used for this purpose and do provide satisfactory feed rate control for both fast and slow portions of the overall feed stroke, air cylinders are more desirable in view of the ease of supply of compressed air as compared to the more complex and expensive equipment required for an hydraulic fluid system.

It is primarily for this purpose that certain prior linear feed devices have made use of an air cylinder for the motive power to move the spindle and tool in the feed stroke, combined with an hydraulic cylinder merely having an hydraulic fluid recirculating system controlling the air cylinder movement, and thereby the spindle and tool movement. This results in the use of the most desirable attributes of both the air and hydraulic systems, yet eliminating the major problems of each. The only supply required for linearly moving the device is that of compressed air due to the hydraulic system for the hydraulic cylinder being strictly of a recirculating nature, yet all of the feed rate control advantages of the hydraulic cylinder are supplied.

Even with the combined air and hydraulic piston control of the fast and slow feed portions of the feed stroke in moving the spindle and tool to and into the work upon which the working operation is to be performed, however, there are still major problems presented in providing the maximum of control of the hydraulic fluid flow in order thatthe hydraulic cylinder may most efficiently control the fast and slow feed rates while still having the slow feed rate fully adjustable as required for different working conditions. Of course for a device of this type having only a single slow feed rate, the hydraulic fluid valving system can be relatively simple, but where a fully versatile device is required having full adjustability of the slow feed rate in order to adapt the same for the various working conditions encountered, quite expensive and complicated hydraulic fluid valving systems can be required according to prior constructions and procedures. One of the problems to be solved, therefore, is just how to provide an hydraulic fluid system which is initially of relatively simple construction, while still providing full adjustability thereof for adapting the slow feed rate of the device to the many working conditions which are foreseeable.

A still further consideration in the provision of air-hydraulic linear feed devices of the type herein involved is one of maximum compactness and simplicity so as to be readily adaptable to ease of portability and usable in working areas of confined space. For maximum compactness and versatility, the fluid motor required for rotatably driving the spindle and tool may be combined movable linearly unitary with the cylinder pistons and the spindle and tool, including the necessary power transmission connections therebetween, but this does not fully solve all of the problems involved. One of the primary problems presented is how to mount the fluid motor at the forward ends of the cylinder pistons so as to be closely axially situated relative to the spindle in order to eliminate long power transmission connections while still supplying fluid thereto, keeping in mind that the fluid motor is constantly for wardly and rearwardly moving throughout the feed and retraction strokes.

OBJECTS AND SUMMARY OF THE lNVENTlON lt is, therefore, an object of this invention to provide an airhydraulic linear feed device of the type in which an air cylinder feed of a rotatable spindle is controlled by an hydraulic cylinder, yet with the hydraulic cylinder fluid flow control being of maximum simplicity while still maintaining full selective adjustability of the slow feed rate. According to certain of the principles of the present invention, the flow of hydraulic fluid in the closed fluid flow system of the hydraulic cylinder is accomplished merely by the provision of a major flow passageway connected between the forward and rearward ends of the hydraulic cylinder and when the controlled slow feed is to commence, the fluid flow in the major passageway is shunted by a single valve through an interconnected restricted hydraulic fluid passageway, a single adjustable metering valve therein provides full adjustability of the slow speed rate, thereby eliminating the complex and expensive valving systems in the hydraulic fluid flowpassageways of the prior constructions. 7

It is a further object of this invention to provide an airhydraulic linear feed device of the foregoing type wherein a full supply of hydraulic fluid in the hydraulic cylinder fluid flow system is automatically maintained at all times while reducing maintenance requirements to a minimum. As provided for by certain of the principles of the present invention, anhydraulic fluid supply chamber is formed on the device in constant connection with the hydraulic fluid flow passageways of the hydraulic cylinder and a constantly resiliently urged plunger is positionedin such supply chamber constantly urging additional hydraulic fluid into the fluid system. In this manner, merely by infrequent maintenance checks and resupply of the hydraulic fluid supply chamber, a full hydraulic fluid supply is always ensured and lack of hydraulic fluid can never cause malfunction of the feed action of the device.

It is also an object of this invention to provide an air-hydraulic linear feed device of the foregoing general type and particularly having a unitary fluid cylinder, fluid motor and rotatable spindle movable forwardly and rearwardly in feed and retraction strokes wherein the fluid motor may be located forwardly closely adjacent the spindle which it is required to rotate and the fluid supply to said fluid motor may be distributed thereto without disturbing the desired compactness of the overall device and may even be controlled merely through feed and retraction movements of the fluid cylinder piston.

Again, according to certain of the principles of the present invention, a piston rod for the fluid cylinder or cylinders for wardly connected to the fluid motor in order to move the fluid motor and spindle forwardly and rearwardly in the feed and retraction strokes is additionally formed as a fluid supply tube for the fluid motor in order to rotatably drive the same. This supply tube piston rod, in turn, rearwardly movably telescopes a stationary fluid supply tube connected to the fluid supply for the fluid motor with porting and channelling between the supply tubes internally of the piston rod supply tube forming the fluid communication therebetween. Still in addition, valve means may be provided between the stationary supply tube and the movable piston rod supply tube internally of the latter which is automatically opened when the fluid cylinder piston and the movable piston rod supply tube are moved forwardly and automatically closed as they are moved rearwardly so as to automatically admit and cut off fluid supply to the fluid motor merely through the feed and retraction motions of the fluid cylinder piston.

Other objects and advantages of the invention will be apparent from the following specification and the accompanying drawings which are for the purpose of illustration only.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an exploded perspective view showing the'major parts of an embodiment of air-hydraulic linear feed device incorporating the principles of the present invention;

FIG. 2 is a rearward end view of the air-hydraulic linear feed device of FIG. I looking in the direction of the arrows 2-2 in FIG. 1;

FIG. 3 is a vertical 3 view looking in the direction of the arrows 33 in FIG. 1;

FIG. 4 is a horizontal sectional view looking in the direction of the arrows 44 in FIG. 3;

PEG. 5 is a vertical sectional view looking in the direction of the arrows 5-S in FIG. 3; and

FIG. 6 is a somewhat diagrammatic view illustrating the various fluid flow systems of the air-hydraulic linear feed device of FIG. 1.

DESCRIPTION OF THE BEST EMBODIMENT CONTEMPLATED Referring to FIG. 1, the embodiment of air-hydraulic linear feed device is shown having the principal working part thereof mounted in and enclosed by a main housing or main frame generally indicated at 10, with FIG. 1 showing various covers and auxiliary parts removed including control rod covers 12 and 14 removed from an upper side of the main frame, a conventional tool chuck l6 removed from a forward portion of a I rotatable spindle l8, and a guide or nose 20 removed from the forward end of the main frame. All of the removed parts are generally of usual constructions and serve the usual and wellknown functions so that the same need not be considered further. Also, the overall air-hydraulic linear feed device shown herein may be formed of usual material to serve the intended function.

More particularly, to the areas of the air-hydraulic linear feed device involving the principles of the present invention, and referring to FIGS. 1 through '5 of the drawings, an air cylinder 22 is formed within the main frame at the rearward extremity thereof, said air cylinder having a piston 24. An hydraulic cylinder 26 is formed directly forwardly of and axially aligned with the air cylinder 22 in the main frame 10 and has an hydraulic cylinder piston 28. Both of the pistons 24 and 28 of the respective air and hydraulic cylinders 22 and 26 are secured to a combined and common piston rod and movable fluid or air supply tube 30 extending axially through both cylinders and being forwardly secured to a frame of an axially aligned fluid or air motor 32.

To complete the prime elements of the overall air-hydraulic linear feed device, a vaned rotor 34 of the air motor 32 is forwardly power transmission connected through a gear train 36 to the forwardly projecting rotatable spindle 18. Thus, without at the moment discussing the details of the air supply to the air cylinder 22, compressed air entering the rearward end of the air cylinder forces the air cylinder piston 24 and through the movable air supply tube 30 acting as the piston rod, the hydraulic cylinder piston 28, the air motor 32, the gear train 36 and the spindle 18, all forwardly as a unit in a feed stroke, with air into the air cylinder in the reverse direction forwardly of the air cylinder piston causing the reverse unitary movement in a retraction stroke. At the same time, by selectively regulating the flow of hydraulic fluid in a closed flow system thereof between the forward and rearward ends of the hydraulic cylinder 26 and to the opposite sides of the hydraulic cylinder piston 28, the hydraulic cylinder may be used for assembly as caused by the air cylinder 22;

Pressurized air for actuating or moving the air cylinder 22 is received into the main frame 10 through a main air inlet 38 and a portion thereof passes into a cylinder air supply passageway 40 rearwardly of the air cylinder 22 extending from the main air inlet transversely of the main frame 10 and then longitudinally or axially adjacent the air cylinder to finally communicate transversely into an intermediate air supply chamber 42 of a cylinder air control spool valve 44. The cylinder air control spool valve 44 is of the type having forwardly and rearwardly pressurized end chambers 46 and 48 constantly in communication with the air supply chamber 42 thereof through appropriate forward and rearward passageways in the spool 50 so that exhausting the pressurized air from either end of said pressurized end chambers causes the spool to move in that direction through the pressurized air in the opposite end chamber and the spool will remain in such position until such opposite end chamber is exhausted. As can be determined from the showing of the spool valve 44 in FIG. 3, when the spool 50 is in its rearward position by the exhaust ing of pressurized air from the rearward pressurized end chamber 48,- that position shown, the air supply chamber 42 of the spool valve is in communication with a rearward cylinder end passageway 52 partially shown in FIG. 3 and shown in hidden lines in FIG. 2, and when the spool of the spool valve is in its forward position by exhausting of the air from the forward pressurized end chamber 46, the air supply chamber 42 is in communication with a forward cylinder end passageway 54 shown in FIG. 3.

A schematic layout of this airflow system including portions thereof to be hereinafter described, and also including a schematic showing of an hydraulic fluid flow system involved with the hydraulic cylinder 26 as will be later described, is shown in FIG. 6. Thus, for a clear understanding now referring to both FIGS. 3 and 6, when the spool 50 of the spool valve 44 is in its rearward position as shown in FIG. 3, the forward cylinder end passageway 54 is sealed off from the air supply chamber 42 but is connected by the spool in communication with a forward air exhaust 56 opening into the atmosphere, and when the spool is in its forward position, the spool seals off the rearward cylinder end passageway 52 from the air supply chamber 42 and places it in communication with a rearward air exhaust 58 opening into the atmosphere. For functioning of the air cylinder 22, the rearward cylinder end passageway 52 from the spool valve 44 is connected into the air cylinder rearward end rearwardly of the air cylinder piston 24, and the forward cylinder end passageway 54 of the spool valve is connected into the forward end of the air cylinder forwardly of the air cylinder piston.

Completing the airflow or air control system for' the air cylinder 22, the rearward pressurized end chamber 48 of the spool valve 44 is connected through a normallyclosed start valve 60 with the atmosphere, actuation of the start valve exhausting air from the rearward pressurized end chamber and causing the spool 50 of the spool valve to move rearwardly to that end. The forward pressurized end chamber 46 of the spool valve 44-is connected through a normally closed emergency reverse valve 62 with the atmosphere and also through a normally closed automatic reverse valve 64 with the atmosphere, actuation or opening of either reverse valve exhausting the pressurized air from the forward pressurized end chamber 46 of the spool valve and causing the spool 50 to move to the forward end. Both the start valve 60 and the emergency reverse valve 62 are manually actuated valves for opening thereof, while the automatic reverse valve 64 is actuated or opened througha forwardly projecting reverse control rod 66 whichis forwardly and rearwardly adjustable and is momentarily urged forwardly to momentarily open the automatic reverse valve 64 at the adjustably determined forward end of the feed stroke as will be hereinafter discussed more in detail by an actuating bar 68 secured to and movable forwardly and rearwardly with the air motor 32 of the unitary forwardly and rearwardly movable assembly as herein before described.

A closed or recirculating hydraulic fluid flow and control system for the hydraulic cylinder 26 includes a major hydraulic fluid passageway 70 connected communicating into the extreme forward and rearward ends of the hydraulic cylinder 26 extending therebetween through the main frame outwardly of the hydraulic cylinder as shown partially in each of FIGS. 2, 3 and 5, and diagrammatically in FIG. 6. Intermediate the extension of the major hydraulic fluid passageway 70 within the main frame 10 is an automatically controlled, closed and open positionable, hydraulic fluid shunting valve 72 having a forwardly projecting and adjustable control rod 74 as best seen in FIGS. 1, 3, 4, 5 and diagrammatically in FIG. 6. The control rod 74 for the hydraulic fluid shunting valve 72 is formed with a radially compressible, colletlike, forward end portion 76 which is compressibly receivable through a reduced opening 78 of the actuating bar 68 previously pointed out, the actuating bar 68 movably telescoping the control rod 74 rearwardly of said forward end portion 76 during an initial portion of the forward feed stroke, ultimately engaging the control rod for ward end portion 76 to shift the control rod and close the hydraulic fluid shunting valve 72 at a determined intermediate part of the feed stroke, and then compressing and passing over said forward end portion 76 to release the control rod for the remainder of the feed stroke, During the retraction stroke, the actuating bar 68 performs reverse action on the control rod 74 to open the hydraulic fluid shunting valve 72, such action being for purposes hereinafter described.

A restricted hydraulic fluid passageway 80 communicates at each end with the major hydraulic fluid passageway 70 shunting around or bypassing the hydraulic fluid shunting valve 72 as is best seen in FIG. 5 and diagrammatically in FIG. 6. The restricted hydraulic fluid passageway 80 is formed in the main frame 10 and intermediate thereof spaced from the major hydraulic fluid passageway 70 passes through an adjustable metering valve 82 which may be adjustably regulated for controlling the rate of hydraulic fluid flow through the restricted hydraulic fluid passageway. Completing the hydraulic fluid flow and control system, an hydraulic fluid supply chamber 84 is connected communicating with the major hydraulic fluid passageway 70 and includes a constantly resiliently urged plunger 85 constantly resiliently urging hydraulic fluid in said supply chamber into the major hydraulic fluid passageway so as to maintain the hydraulic fluid system full at all times and replacing any loss therefrom during operation of the device of the present invention.

Fluid or air supply for the air motor 32 is also received through the main air inlet 38 and forwardly into an axially extending, stationary air supply tube 86 which extends coaxially of the movable air supply tube forming the piston rod for the air and hydraulic cylinder pistons 24 and 28, being movably telescoped by a rearward portion of said movable air supply tube. A series of outlet ports or openings 88 are formed through the wall of the stationary air supply tube 86 spaced rearwardly of a closed end surface 90 thereof and from said outlet ports to said end surface, the outer portion of the stationary air supply tube is radially recessed or relieved to provide an air communication from said outlet ports outwardly around said end surface. The forward end of the movable air supply tube 30 is connected communicating with the air motor 32 for supplying driving air thereto and the movable air supply tube is internally formed with an annular shoulder 92 having a rearwardly facing, annular valve seat 94 formed thereon, the valve seat tightly rearwardly abutting the end surface 90 of the stationary air supply tube 86 when the movable air supply tube is in fully retracted position and immediately moving forwardly axially away from the end surface of the stationary air supply tube at commencement of the feed stroke. The valve seat 94, therefore, seals off air communication between the stationary air supply tube 86 and the movable air supply tube 30 when the movable air supply tube is in fully retracted position, but permits free air passage and to the air motor 32 when the movable air supply tube is in any forward position during the feed and retraction strokes.

In operation of the embodiment of the air-hydraulic linear feed device of the present invention herein shown and described, prior to the commencement of a feed and retraction stroke cycle, the unitary assembly of the air and hydraulic cylinder pistons 24 and 28, the movable air supply tube 30 forming the piston rod, the air motor 32, the gear train 36 and the spindle I8, is in fully retracted position as shown in FIGS. I, 3 and 4, but the spool 50 of the cylinder air control spool valve 44 is shifted forwardly from the position shown in FIGS 3 and 4. An air supply (not shown) is connected to the main air inlet 38 with air passing through the cylinder air supply passageway 40, through the air supply chamber 42 of the spool valve 44, through the forward cylinder end passageway 54 and into the air cylinder 22 forwardly of the air cylinder piston 24 so as to, at this point, retain the unitary assembly stationary. At the same time, air passes forwardly through the stationary air supply tube 86, but cannot pass forwardly into the movable air supply tube 30-in view of the sealing of the valve seat 94 rearwardly against the forward end surface of the stationary air supply tube.

In this fully retracted position of the various elements of the device, the actuating bar 68 is rearwardly telescoping both the reverse control rod 66 for the automatic reverse valve 64 and the control rod 74 for the hydraulic fluid shunting valve 72 spaced rearwardly from the forward ends of said control rods, so that the automatic reverse valve 64 remains closed and the hydraulic fluid shunting valve 72 is positioned open. The hydraulic fluid flow and control system for the hydraulic cylinder 26 being a closed recirculating system'as previously described is full of hydraulic fluid as maintained by the hydraulic fluid supply chamber 84 so that there is hydraulic fluid at both the forward and rearward sides of the hydraulic cylinder piston 28 within thehydraulic cylinder. In view of the lack of motion of the hydraulic cylinder piston 28, ball checks 96 of the hydraulic cylinder piston 28 are static within or at least partially within bypass ports 98 of the hydraulic cylinder piston being prevented from moving forwardly totally out of said ports by a retaining plate 100, the purpose of this portion of the construction to be hereinafter pointed out.

Thus, the air-hydraulic linear feed device is ready for the commencement of a feed and retraction stroke cycle which is initiated by manually depressing the start valve 60 to open the same. Opening of the start valve 60 exhausts the pressurized air from the rearward pressurized end chamber 48 of the cylinder air control valve 44 causing the spool 50 of said valve to shift rearwardly to the position shown in FIGS. 3 and 4. The supply of air through the cylinder air supply passageway 40 to the cylinder air control spool valve 44 is, therefore, directed to the rearward cylinder end passageway 52 and into the rear ward end of the air cylinder 22 rearward of the piston 24, the forward cylinder end passageway 54 of the air cylinder being connected by the valve to the forward air exhaust 56.

The feed stroke of the device is thereby started and the air cylinder piston 24 begins to move the hydraulic cylinder piston 28, the air motor 32, the gear train 36 and the spindle l8 forwardly in such feed stroke. Immediately upon the initiation of forward movement in this feed stroke, the movable air supply tube 30 forming the common piston rod for the air and hydraulic cylinder pistons 24 and 28 moves the valve seat 94 thereof forwardly away from the end surface 90 of the sta tionary air supply tube 86 permitting a supply of air to flow forwardly within the stationary and movable air supply tubes to the air motor 32 starting rotation of the rotor 34 thereof and rotational drive of the gear train 36 and spindle 18. Also, forward feed stroke movement of the air and hydraulic cylinder pistons 24 and 28 begins a flow of hydraulic fluid from the forward end of the hydraulic cylinder 26 through the major hydraulic fluid passageway 70 and the open hydraulic fluid shunting valve 72 into the rearward end of the hydraulic cylinder, permitting the higher linear speed feed movement of the device as controlled by this hydraulic cylinder, the forward pressure of the hydraulic cylinder piston 28 against the hydraulic fluid causing the ball cheeks 96 to be forced rearwardly and close the bypass ports 98 so that the hydraulic cylinder piston acts as a solid piston during this feed stroke.

The fast portion of the forward feed stroke of the device continues until the actuating bar 68 connected movable forwardly with the various elements engages the preset positioned forward end portion 76 of the control rod 74 for the hydraulic fluid shunting valve 72. This momentary engagement of the forward end portion 76 of the control rod 74 moves the control rod forwardly closing the hydraulic fluid shunting valve 72 after which, the control rod forward end portion is radially compressed by the actuating bar 68 permitting the actuating bar to move forwardly free of said control rod and continue its forward movement. Furthermore, the closing of the hydraulic fluid shunting valve 72 shunts the hydraulic fluid in the hydraulic fluid flow and control system of the hydraulic cylinder 26 through the restricted hydraulic fluid passageway 80, the flow therein being preset by the mctering valve 82, and this restricted flow for the hydraulic cylinder piston 28 through the control thereof over the air cylinder piston 24 causes the commencement of the slow portion of the forward feed stroke of the device.

The slow portion of the forward feed stroke of the device continues in this precalculated manner until the actuating bar 68 engages the enlarged end of the reverse control rod 66 which has been adjustably prepositioned and moves this reverse control rod forwardly, as shown in phantom lines in FIG. 4, to momentarily open the automatic reverse valve 64. The momentary opening of the automatic reverse valve 64 exhausts the pressurized air from the forward pressurized end chamber 46 of the cylinder air control spool valve 44 shifting the spool 50 thereof forwardly and reversing the direction of the air supply through the cylinder air supply passageway 40 into the forward cylinder end passageway 54 forwardly of the air cylinder piston 24, while connecting the rearward cylinder end passageway 52 with the rearward air exhaust S8. The movement of the air cylinder piston 24 is thereby reversed and started rearwardly commencing rearward retraction movement of the hydraulic cylinder piston 28, the air motor 32, the gear train 36 and the spindle 18.

As the hydraulic cylinder piston 28 is begun to be moved rearwardly in this retraction stroke, the hydraulic fluid flow in the flow and control system of the hydraulic cylinder 26 is reversed, but at the same time, the reverse or rearward pressure of the hydraulic cylinder piston against the hydraulic fluid within the hydraulic cylinder causes the hydraulic fluid to enter the bypass ports 88 of the piston and move the ball checks 96 away from these ports and against the retaining plate 100 so as to permit a relatively free flow of hydraulic fluid through the hydraulic cylinder piston and permit a fast retraction stroke. During the initial portion of the fast retraction stroke, the actuating bar 68 moves rearwardly and ultimately releases the reverse control rod 66 permitting the automatic reverse valve 64 to reclose ready for a following start of another feed and retraction stroke of the device. Also, intermediate the fast retraction stroke, the actuating bar 68 reengages the forward end portion 76 of the control rod 74 for the hydraulic fluid shunting valve 72 reopening this shunting valve to likewise place the same in position for another feed and retraction stroke cycle, although the hydraulic fluid within the hydraulic cylinder 26 still continues to pass rearwardly through the bypass ports 98 of the hydraulic cylinder piston 28. l

The fast retraction stroke is terminated and the device is ready for the start of another fast feed portion of the feed stroke when the air cylinder piston 24 reaches and abuts the rearward end of the air cylinder 22 stopping rearward movement of the air cylinder piston, the hydraulic cylinder piston 28, the air motor 32, the gear train 36 and the spindle 18. This rearward retraction movement stopping also engages the valve seat 94 of the movable air supply tube 30 with the forward end surface 90 of the stationary air supply tube 86 sealing oh the Flow nf air in the air mnmr 32 and nermittinu the air motor tional rest. The air-hydraulic linear feed device is, therefore, ready for the commencement of another feed and retraction stroke cycle with the action of the various elements thereof being an exact repeat of that described.

The emergency reverse valve 62 connected to the forward pressurized end chamber 46 of the cylinder air control spool valve 44 which controls the air supply to the air cylinder 22 is for the purpose of terminating the feed stroke of the device at any portion thereof, whether fast or slow feed, when something occurs in the working operation requiring immediate termination thereof. Merely by depressing and thereby momentarily opening the emergency reverse valve 62 exhausts the pressurized air from the forward pressurized end chamber 46 of the cylinder air control spool valve 44 so as to shift the spool 50 rearwardly into the retraction stroke position. A further supplementary construction which may be included in the device is an auxiliary control valve 102 engagcable by the air cylinder piston 24 as the air cylinder piston comes to rest rearwardly in the air cylinder 22 and the auxiliary control valve can be used to control any exterior device in the usual manner as desired.

According to the principles of the present invention, therefore, an air-hydraulic linear feed device is provided having an air cylinder 22 for moving a rotating spindle 18 in feed and retraction strokes, the feed rate being controlled by the hydraulic fluid flow of an hydraulic cylinder 26. Furthermore, the hydraulic fluid flow of the hydraulic cylinder 26 is very accurately and selectively adjustably controlled in an extremely simplified manner permitting the maintenance of fast and slow feed rates in a manner not heretofore possible. Still in addition, by the provision of unique air supply control to the air motor 32 rotatably driving the working spindle 18, the air motor may be positioned forwardly relatively close to the spindle, yet compactness of the device is maintained and the air supply for the air motor is automatically cut off at the end of the retraction stroke and reopened at the commencement of the feed stroke byv a simplified arrangement of elements.

lclaim:

1. in an air-hydraulic linear feed device of the type incorporating a main frame mounting an air cylinder having a piston movable forwardly in a feed stroke and rearwardly in a retraction stroke with said air cylinder piston being controlled at least in said forward feed stroke by a piston of an hydraulic cylinder, a rotatable spindle operably connected to said air cylinder piston forwardly and rearwardly movable thereby, and a motor operably connected to said spindle rotating said spindle during at least forward parts of said air cylinder piston feed and retraction strokes; the improvement comprising: a major hydraulic fluid passageway connection communicating into and between forward and rearward ends of said hydraulic cylinder, said major passageway connection at said hydraulic cylinder forward end being forwardly of said hydraulic piston when said air piston is at a forward end of said feed stroke, said major passageway connection at said hydraulic cylinder rearward end being rearwardly of said hydraulic piston whpn said air piston is at a rearward end of said retraction stroke; a restricted hydraulic fluid passageway connection communicating into and between spaced locations along said major hydraulic fluid passageway; a valve in said major hydraulic fluid passageway located intermediate said major passageway spaced locations movable between open and closed positions, said valve in said open position permitting a free flow of hydraulic fluid through said major hydraulic fluid passageway from said forward to said rearward hydraulic cylinder ends during an initial fast part of said air cylinder feed stroke, said valve in said closed position stopping said free flow and forcing restricted flow of said hydraulic fluid through said major and said restricted hydraulic fluid passageways from said forward to said rearward hydraulic cylinder ends during a remaining slow part of said air cylinder feed stroke.

2. An air-hydraulic linear feed device as defined in claim 1 in which said restricted hydraulic fluid passageway includes a selectivelv adiustable meterin valve therein adiustablv re u- 3. An air-hydraulic linear feed device as defined in claim 1 in which said major hydraulic fluid passageway includes an hydraulic fluid supply chamber connection communicating therewith, a resiliently urged plunger in said supply chamber constantly exerting a resilient pressure on hydraulic fluid in said supply chamber urging said hydraulic fluid into said major hydraulic fluid passageway.

4. An air-hydraulic linear feed device as defined in claim 1 in which said air cylinder and said hydraulic cylinder and said motor are axially aligned in order from rearwardly to forwardly of said main frame, said air cylinder and hydraulic cylinder pistons being axially connected, a piston rod of said hydraulic cylinder piston being forwardly connected to a casing of said motor moving said motor forwardly and rearwardly with said air and hydraulic cylinder pistons during said feed and retraction strokes, said spindle being operably connected movably with said motor.

5. An air-hydraulic linear feed device as defined in claim 1 in which said valve in said major hydraulic fluid passageway includes a valve body on said main frame, a valve actuator in said valve body movable forwardly into said valve-closed position and rearwardly into said valve-open position, valve control means operably connected to said air cylinder piston and operably connected to said valve actuator at least during certain periods of said feed and retraction strokes for moving said valve actuator forwardly to close said valve during said feed stroke and moving said valve actuator rearwardly to open said valve during said retraction stroke.

6. An air-hydraulic linear feed device as defined in claim 1 in which said valve in said major hydraulic fluid passageway includes a valve body on said main frame, a valve actuator in said valve body movable forwardly to a valve-closed position and rearwardly to a valve-open position, said valve actuator projecting forwardly from said valve body and having a radially depressible colletlike forward end portion thereon, a valve control bar operably connected to and movable with said air cylinder piston, said valve control bar having an opening formed therethrough aligned with said valve actuator forward end portion and of spaced smaller dimensions than said valve actuator colletlike end portion, said valve control bar receiving said valve actuator slidably therethrough during rearward parts of said feed and retraction strokes, said valve control bar momentarily engaging said valve actuator colletlike end portion at termination of said valve actuator reception during said feed stroke and at initiation of said valve actuator reception during said retraction stroke moving said valve actuator to valve-closed position during said feed stroke and valve-open position during said retraction stroke.

7. An air-hydraulic linear feed device as defined in claim 1 in which said motor operably connected to said spindle is a fluid motor; and in which a motor fluid supply includes a stationary motor fluid passageway connectable to a fluid source rmd having a fluid exit portion, an axially movable motor fluid passageway connected to and axially movable forwardly and rearwardly exactly with said air cylinder piston, said movable fluid passageway having a fluid entrance portion constantly connected to and axially movable relative to said fluid exit portion of said stationary fluid passageway, said movable fluid passageway having a fluid exit portion constantly communicating with said fluid motor, fluid valve means formed by certain of said fluid exit portion. of said stationary fluid passageway and said fluid entrance portion of said movable fluid passageway automatically through said movable fluid passageway movement closing at a determined position of said air cylinder piston in said retraction stroke preventing fluid communication to said fluid motor and automatically through said movable fluid passageway movement opening at a determined position of said air cylinder piston in said feed stroke permitting fluid communication to said fluid motor.

8. An air-hydraulic linear feed device as defined in claim 1 in which said restricted hydraulic fluid passageway includes a selectively adjustable metering valve therein regulating the flow of hydraulic fluid therethrough; and in which said major hydraulic fluid passageway includes a fluid supply chamber connection communicating therewith, a constantly resiliently urged plunger in said fluid supply chamber bearing against hydraulic fluid in said fluid supply chamber and constantly urging said hydraulic fluid into said major hydraulic fluid passageway.

9. An air-hydraulic linear feed device as defined in claim I in which said motor operably connected to said spindle is a fluid motor and is connected movably forwardly and rearwardly exactly with said air cylinder piston; in which said air cylinder piston and said hydraulic cylinder piston and said fluid motor are axially aligned in order from rearwardly to forwardly of said main frame; and in which a motor fluid supply includes a stationary motor fluid supply tube extending axially ofand telescoped by said air cylinder piston, said stationary motor fluid supply tube being connectable rearwardly to a fluid source and having a forward fluid exit portion, an axially movable motor fluid supply tube secured to said air and hydraulic cylinder pistons extending axially of said pistons and forming a common piston rod therefor, said movable fluid supply tube having a fluid entrance portion constantly rearwardly telescoping and axially movable relative to said fluid exit portion of said stationary fluid supply tube, said movable fluid supply tube having a fluid exit portion forwardly at said fluid motor secured to and constantly communicating with said fluid motor, fluid valve means formed by certain of said fluid exit portion of said stationary fluid supply tube and said fluid entrance portion of said movable fluid supply tube automatically through said'movable fluid supply tube movement closing at a determined position of said movable fluid supply 'tube during said retraction stroke preventing fluid communication to said fluid motor and automatically through said movable fluid supply tube movement opening at a determined position of said movable fluid supply tube during said feed stroke permitting fluid communication to said fluid motor.

10, An air-hydraulic linear feed device as defined in claim I in which said restricted hydraulic fluid passageway includes a selectively adjustable metering valve therein adjustably regulating the flow of hydraulic fluid therethrough; in which said motor operably connected to said spindle is a fluid motor and is connected movably forwardly and rearwardly exactly with said air cylinder piston; in which said air cylinder piston and said hydraulic cylinder piston and said fluid motor are axially aligned in order from rearwardly to forwardly of said main frame; and in which a motor fluid supply includes a stationary motor fluid supply tube extending axially of and telescoped by said air cylinder piston, said stationary motor fluid supply tube being connectable rearwardly to a fluid source and having a forward fluid exit portion, said stationary motor fluid supply tube terminating forwardly of said forward fluid exit portion in a tube end, an axially movable motor fluid supply tube secured to said air and hydraulic cylinder pistons extending axially of said pistons and forming a common piston rod therefor, said movable fluid supply tube having a fluid entrance portion con stantly rearwardly telescoping and axially movable relative to said fluid exit portion and said tube end of said stationary fluid supply tube, said movable fluid supply tube having a fluid exit portion forwardly at said fluid motor secured to and constantly communicating with said fluid motor, an annular shoulder formed internally of said movable fluid supply tube forwardly of said fluid entrance portion thereof tightly rearwardly abutting said tube end of said stationary fluid supply tube upon said air and hydraulic cylinder pistons moving fully rearwardly to fully retracted position preventing fluid communication to said fluid motor, separation of said shoulder and tube end of said movable and stationary fluid supply tubes upon forward movement of said air and hydraulic cylinder pistons at commencement of said feed stroke permitting fluid communication to said fluid motor.

11. in a fluid-driven linear feed device of the type incorporating a main frame mounting a fluid cylinder having a piston movable forwardly in a feed stroke and rearwardly in a retraction stroke, a rotatable spindle operably connected to said fluid cylinder piston forwardly and rearwardly movable thereby, and a fluid motor operably connected to said spindle rotating said spindle during at least forward parts of said fluid cylinder piston feed and retraction strokes; the improvements comprising: a cylinder fluid supply including cylinder fluid passageways connectable to a fluid source and connected into said fluid cylinder at axially opposite sides of said fluid cylinder piston, a cylinder fluid control valve connected to said cylinder fluid passageways directing fluid through said passageways into said cylinder rearwardly of said piston in a feed position during said piston feed stroke and through said passageways into said cylinder forwardly of said piston in a retraction position during said piston retraction stroke; and a motor fluid supply including a stationary motor fluid passageway connectable to a fluid source and having a fluid exit portion, an axially movable motor fluid passageway connected to and axially movably forwardly and rearwardly exactly with said fluid cylinder piston, said movable fluid passageway having a fluid entrance portion constantly con nected to and axially movable relative to said fluid exit portion of said stationary fluid passageway, said movable fluid passageway having a fluid exit portion constantly communicating with said fluid motor, fluid valve means formed by certain of said fluid exit portion of said stationary fluid passageway and said fluid entrance portion of said movable fluid passageway automatically through said movable fluid passageway movement closing at a determined position of said fluid cylinder piston in said retraction stroke preventing fluid communication to said fluid motor and automatically through said movable fluid passageway movement opening at a determined position of said fluid cylinder piston in said feed stroke permitting fluid communication to said fluid motor.

12. A fluid-driven linear feed device as defined in claim 11 in which said stationary motor fluid passageway includes a stationary fluid supply tube secured to said main frame and extending coaxially of and movably telescoped by said fluid cylinder piston; and in which said movable fluid passageway includes a movable fluid supply tube forming a piston rod for said fluid cylinder piston, said movable fluid supply tube rearwardly movably telescoping said stationary fluid supply tube.

13.. A fluid-driven linear feed device as defined in claim 11 in which said fluid valve means of said motor fluid supply includes a valve seat formed by certain of said stationary and movable fluid passageways engaged and closed upon full rearward movement of said movable fluid passageway at termination of rearward retraction movement of said fluid cylinder piston, said valve seat being disengaged and open during initial forward movement of said movable fluid passageway during initial forward movement in said feed stroke of said fluid cylinder piston.

14. A fluid-driven linear feed device as defined in claim 11 in which said stationary motor fluid supply passageway includes a stationary fluid supply tube secured to said main frame and extending coaxially of and movably telescoped by said fluid cylinder piston; in which said movable fluid passageway includes a movable fluid supply tube forming a piston rod for said fluid cylinder piston, said movable fluid supply tube rearwardly movably telescoping said stationary fluid supply tube; in which said fluid valve means of said motor fluid supply includes a valve seat formed by certain of said stationary and movable fluid supply tubes engaged and closed upon full rearward movement of said movable fluid supply tube at termination of rearward retraction movement of said fluid cylinder piston, said valve seat being disengaged and open during initial forward movement of said movable fluid supply tube during initial forward movement in said feed stroke of said fluid cylinder piston.

15 A fluid-driven linear feed device as defined in claim 11 in which said stationary motor fluid passageway includes a stationary fluid supply tube secured to said main frame and extending coaxially of and movably telescoped by said fluid cylinder piston, said stationary fluid supply tube terminating forwardly in a tube end with said fluid exit portion of said stationary fluid supply tube being rearwardl of said tube end; in which said mova le fluid passageway inc udes a movable fluid supply tube forming a piston rod for said fluid cylinder piston, said movable fluid supply tube at all times rearwardly movably telescoping said tube end and said fluid exit portion of said stationary motor fluid supply tube; and in which said fluid valve means of said motor fluid supply includes an annular shoulder internally of said movable motor fluid supply tube rearwardly abutting said tube end of said stationary motor fluid supply tube when said fluid cylinder piston is in fully retracted position, said shoulder of said movable motor fluid supply tube moving forwardly away from said tube end of said stationary motor fluid supply tube upon commencement of said feed stroke by said fluid cylinder piston, a fluid passageway formed axially between said stationary and movable motor fluid supply tubes from said fluid exit portion and along said tube end of said stationary motor fluid supply tube forming fluid communication from said fluid exit portion of said stationary motor fluid supply tube into said movable motor fluid supply tube adjacent said shoulder thereof upon said fluid cylinder piston commencing movement forwardly in said feed stroke.

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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3773117 *Mar 31, 1971Nov 20, 1973Wilson T IncReversible drive tool
US5340243 *Jul 2, 1992Aug 23, 1994Cooper Industries, Inc.Airfeed peck drill configuration
US5348427 *Jul 2, 1992Sep 20, 1994Cooper Industries, Inc.Airfeed peck drill configuration
US5374143 *Nov 9, 1993Dec 20, 1994Cooper Industries, Inc.Air feed peck drive configuration
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US5833404 *May 24, 1996Nov 10, 1998Cooper Industries, Inc.Portable peck feed drilling system
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Classifications
U.S. Classification91/61, 92/12, 60/387, 91/517, 91/519
International ClassificationF15B11/076
Cooperative ClassificationF15B2211/8855, F15B2211/40515, F15B11/076, F15B2211/30525, F15B2211/30565, F15B2211/7055, F15B2211/75
European ClassificationF15B11/076