US3626967A

US3626967A - Distributing air valve unit

Info

Publication number: US3626967A
Authority: US
Inventors: Donald J Mccarthy
Original assignee: Jacobs Manufacturing Co
Current assignee: Jacobs Vehicle Systems Inc
Priority date: 1968-10-21
Filing date: 1970-01-30
Publication date: 1971-12-14
Anticipated expiration: 1988-12-14

Abstract

A pneumatically operable air-distributing valve unit designed for incorporation in the body of a collet-actuating piston of an air chuck. It is selectively operable to cause live source air to be applied to one or the other ends of the piston chamber. It includes a pair of end cams between which a porting valve is reciprocable. As the valve is reciprocated from one position to another, it cooperates with one or the other of the cams to cause the valve to be indexed angularly 45* from its last position. In this action, air feed and exhaust ports are caused to be brought alternately into register with ports leading to one or the other ends of the piston chamber or are caused to be shut off from both ends of the chamber.

Description

United States Patent [72] Inventor Donald J. McCarthy Wethersfield, Conn. [21] App]. No. 7,120 [22] Filed Jan. 30, 1970 [45] Patented Dec. 14, I971 [73] Assignee The Jacobs Manufacturing Company West Hartford, Conn. Original application Oct. 21, 1968, Ser. No. 769,141, now Patent No. 3,521,894, dated July 28, 1970. Divided and this application Jan. 30, 1970, Ser. No. 7,120

[54] DISTRIBUTING AIR VALVE UNIT 6 Claims, 18 Drawing Figs.

[52] [1.8. CI. 137/106, 137/119, 137/624.18 [51] Int. Cl 605d 7/00 [50] Field otSearch 137/102, 119, 625.29,106

[56] References Cited UNITED STATES PATENTS 1,326,046 12/1919 Goodhue 137/119 Primary Examiner-Laverne D. Geiger Assistant ExaminerDavid J. Zobkiw AnorneyStephen .1. Rudy ABSTRACT: A pneumatically operable air-distributing valve unit designed for incorporation in the body of a collet-actuating piston of an air chuck. It is selectively operable to cause live source air to be applied to one or the other ends of the piston chamber. It includes a pair of end cams between which a porting valve is reciprocable. As the valve is reciprocated from one position to another, it cooperates with one or the other of the cams to cause the valve to be indexed angularly 45from its last position. In this action, air feed and exhaust ports are caused to be brought alternately into register with ports leading to one or the other ends of the piston chamber or are caused to be shut off from both ends of the chamber.

PATENTEDBEMMBYI 3326.967

SHEET 1 or 3 ATTORNEY PATENTED mm 4 ram FIG].

INVENTORS 66914190 5 HA V/Lfl/VD ATTORNEY PATENTEDDEBMISTI $6253 7 SHEET 3 OF 3 F/G. l4

ATTORNEY DISTRIBUTING AIR VALVE UNIT This is a division of application Ser. No. 769,141, filed Oct. 21, 1968, now Pat. No. 3,521,894, dated July 28, 1970.

This invention is directed to an air-distributing valve designed for feeding operating air alternately at the will of the operator to opposite ends of a piston chamber of an air chuck in which a piston is selectively reciprocable to actuate a chuck collet.

The distributing valve is of a small and compact size designed to be incorporated in the body of the piston. It is adapted to be connected in the air supply line for the chuck. It is selectively operable to cause operating air to be applied alternately to opposite ends of the piston.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. I is a rear end view in elevation of an air chuck embodying the invention;

FIG. 2 is a section on line 22 of FIG. I; the broken line portion at the left representing a hollow driving spindle;

FIG. 3 is a fragmentary detail of FIG. 2 showing the chuck with its components in gripping condition;

FIG. 4 is a fragmentary detail of the rear face of the piston;

FIG. 5 is a section on line 5-5 of FIG. 4;

FIG. 6 is a section on line 66 of FIG. 4;

FIG. 7 is a section on line 7-7 of FIG. 4;

FIG. 8 is a fragmentary section on line 8-8 of FIG. 2;

FIG. 9 is a detail in side elevation of the left cam member;

FIG. 10 is a right end view ofFIG. 9;

FIG. 11 is a section on line 1 111 of FIG. 10;

FIG. 12 is a detail in side elevation of the right cam member;

FIG. 13 is a left end view of FIG. 12;

FIG. 14 is a section on line 14-14 ofFIG. 13;

FIG. 15 is a detail in side elevation of the indexing valve;

FIG. 16 is a right end view of FIG. 15; FIG. 17 is a section on line 17-17 of FIG. 16; and FIG. 18 is a section on line I8 18 of FIG. 16.

DESCRIPTION OF A PREFERRED EMBODIMENT An air chuck 10 shown in the drawing as embodying the invention is adapted to be mounted by means of lugs 12 to an open-ended driving spindle ll of a machine lathe. The chuck includes a body portion 13 having a coned recess 15 in which a conventional collet I6 is adapted to be contracted or caused to be relaxed relative to a workpiece 21 by means of a nosepiece 22 carried by an axially slidable sleeve 29.

Forward or rearward movement of the sleeve and, as a consequence, of the nosepiece so as to grip or loosen the collet about the work is selectively controlled by means of a pneumatically operable annular piston 38 which is reciprocable in a chamber 39 surrounding the sleeve. When the piston is pneumatically moved to a forward normal position, as in FIG. 2, the collet is caused to be loosened; and when it is pneumatically moved to its rearward position, as in FIG. 3, the collet is caused to grip the work.

A pneumatically operable air distribution or sequence valve unit 64 (FIG. 8) incorporated in a bore 65 of the body of piston 38 is selectively operable to cause live airflow from a connected external source to one or the other ends of the piston chamber 39. The valve unit includes a pair of stationary open-ended cam members 66 and 67 (FIGS. 8, 9, 12) between which a porting valve 68 (FIGS. 8, I5) is axially reciprocable. As the valve is reciprocated from one position to another, it cooperates with one or the other of the cam members whereby the valve is caused to be indexed angularly a distance of 45 from its last position. In this action, air feed and exhaust ports are caused to be brought alternately into register with ports leading to one or the other ends of the piston chamber or are caused to be shut off from both ends of the piston chamber, as will soon be described herein.

The cam member 66 (FIGS. 8-11) shown at the left in FIG. 8, is formed with a radial shoulder 69 around its periphery which is held seated upon an annular shoulder 71 defined by an enlargement of the left end of the valve bore 65. A plug 72, threadedly engaged in the end of the bore so as to abut the cam member, seals the left end of the bore and holdsthe cam member rigidly against the shoulder. A cylindrical reduced body portion 73 of the left cam projects axially into the bore 65. The body 73 of the cam is defined by means of a succession of axially extending cam fingers 74, here four in number, spaced circumferentially equally apart. Each finger comprises an axially extending straight side 75, from the extremity of which a cam surface 76 declines counterclockwise to a point separated by a narrow space 77 from the straight side of the next finger.

The right cam member 67 (FIGS. 8, 12-14) is of similar form except that the cam surfaces 78 of its fingers 79 decline in an opposite or clockwise direction. The peripheral radial shoulder 80 of the right cam is rigidly held seated upon a shoulder 81 (clearly shown in FIG. 5) of an enlargement at the right end of bore 65 by means of a plug 82 (FIG. 8) threadedly engaged in and sealing the right end of the bore.

The porting valve 68 (FIGS. 8, 15-18) has a cylindrical body that is slidable axially in the bore 65 between the cam members. The ends of the body are defined by

cam fingers

83 and 84 which respectively complement the

fingers

74 and 79 of the left and right cam members. A compression spring 85 seated at one end against the right closure plug 82 and extending through the interior of the right cam member into an axial recess of the valve biases the latter to a normal or returned position (FIG. 8) wherein its cam fingers 83 are engaged with those 74 of the left cam member. Valve 68 has a pneumatically actuated position (not shown) wherein the fingers 84 at its right end are similarly engaged with those 79 of the right cam member. A pilot pin 86, fixed in the right plug, projects axially into the spring 85 to guide the spring and limit radial movement of the spring caused by centrifugal forces. The inner diameter faces of the fingers 84 of the right cam are axially extended as at 88 beyond the extremities of the fingers to further guide and limit radial movement of the spring.

The right cam member has an angularly advanced position relative to the left cam member 66 so that its fingers 79 are positioned 45 out of phase from those 74 of the left cam member. In this arrangement, when the valve 68 is in its normal or left position, the crests of the fingers 84 at its right end are opposite the midpoints of the cam surfaces 78 of the fingers 79 of the right cam member. By means of this arrangement, each time the valve is moved from engagement with one cam member into axial engagement with the other, it will be cammed and rotatively indexed 45 in a clockwise direction.

This indexing feature permits selective porting of the valve with opposite ends of the piston chamber. To this end, the valve has a pair of inlet or feed ports 89 (FIGS. 8, 18) opening out of its surface at diametrically opposite points. These ports are in communication through the body of the valve with an inlet recess'9l at the left end of the valve. The recess connects, as appears in FIG. 8, through the interior of the left cam member and ports 92 in the cam shoulder with a surrounding air inlet annulus 93. The valve also has a pair of exhaust ports 94 (FIG. 17) opening out of its surface at diametrically opposite points. These ports communicate through the body of the valve with the recess 90 at the front end of the valve. The recess 90 communicates the interior of the valve with ports 95 leading through the shoulder of the right cam member to a surrounding exhaust annulus 96. The latter connects by a passage 97 through the body of the piston with the vent annulus 52. The

several ports

89 and 94 lie in a common plane perpendicular to the axis of the valve and are spaced circumferentially 90 apart. The bore 65 in which the valve operates is connected with the left end of the piston chamber (FIGS. 4, 5, 7, 8) by means of a pair of diametrically opposed ports 98 extending through the piston body; and is connected with the right end of the piston chamber (FIGS. 4, 5, 6, 8) by means of a second pair of diametrically opposed ports 99 extending through the piston body. The

several ports

98 and 99 lie in a common plane perpendicular to the axis of the valve, and are spaced 90 apart. In the nonnal condition of the valve as in FIG. 8, the

ports

89 and 94 of the valve are not only out of re gister with the

ports

98 and 99, but also are angularly disposed 45 out of phase with the latter ports. Each time the valve is shifted to the right in engagement with the right cam, it is indexed 45 clockwise, and two of the four

ports

89, 94 are brought into register with the ports 98 leading to the left side of the piston chamber, and two are brought into register with the ports 99 leading to the right side of the piston chamber, as will soon be further described.

The inlet annulus 93 to the valve is connected with an external source S of operating pressure air. In this respect, a feed line 101 (FIG. 2) extending through the interior of the lathe spindle 11 connects the air source with a single passage air swivel joint 102. The swivel joint is of a conventional type. It is connected with a passage 103 leading through an adapter 104 screwed in the left end of the chuck body. The passage 103 extending through the adapter connects with a passage 105 leading through the chuck body into the interior of a tube 106. The tube is fixed in the chuck body and has an open end which projects with a slide fit part way into an axial bore 107 in the piston body. The forward end of this bore 107 communicates by means of a passage 108 (FIG. 5) through the piston body with the inlet annulus 93 (FIGS. 5, 8) of the valve.

Assuming that the chuck is in its normal condition, as in FIG. 2, in which the condition of the colletl6 is relaxed relative to the, workpiece, the operation of the air chuck is as follows:

A main three-way supply valve 109 in the supply line 101 is turned from closed to open condition. Live air then flows through the connecting passages, described above, to the inlet annulus 93 of the valve bore 65 from where it passes through the left cam66 into the valve inlet recess 91 to shift the valve 68 to the right into camming engagement with the right cam 67. In this action, valve 68 is cammed and indexed clockwise 45 to register its two feed ports 89 with the two ports 99 leading to the right end of the piston chamber, and to register its two vent ports 94 with the two ports 98 leading to the left end of the piston chamber 39. Accordingly, the piston is forced to the left to the FIG. 3 position; and air trapped at the left of the piston chamber is vented through the valve body and connecting passages to the annulus 52 about the piston leading to the vent ports 53. Left or rearward movement of the piston forces the sleeve 29 and nosepiece 22 axially rearward, as earlier explained, to contract the collet 16 into gripping relation with the workpiece 21.

Subsequent to the rearward or leftward movement of the piston, the supply valve I09 is manipulated to its vent position so as to allow air trapped at the left end of the indexing valve 68 to be vented. The valve return spring 85 then relaxes to shift the valve 68 back to its normal condition in engagement with the left cam, as in FIG. 8. The return movement of valve 68 in cooperation with the left cam 66 carries the

valve ports

89, 94 out of register from the

ports

95, 98, and indexes the valve 45 further clockwise preparatory to subsequent shifting of the valve to the right. Returning the sequence valve to its normal position at the left does not affect the position of the piston. The piston remains in its moved condition until pneumatically reshifted to the right.

To move the piston back to its normal position at the right so as to free the collet from its gripping relation with the workpiece, the main valve 109 is again manipulated to open condition. Live air then flowing through the left cam 66 to the rear recess 91 of the valve shifts the valve to the right as before and indexes it a further 45 clockwise causing the two feed ports 89 of the valve to be registered this time with the ports 98 leading to the left end of the piston chamber, and the vent ports 94 to be registered with the ports 99 leading to the right end of the piston chamber, Accordingly, the right end of the piston chamber is vented and the piston is simultaneously moved to the right to its normal condition. Manipulating the main valve 109 to vent condition again causes simultaneous return of the sequence valve 68 to the left normal position and indexing thereof clockwise a further 45.

It is to be noted that the sequence valve permits the chuck to be used with a single three-way main valve 109 and a single air supply line 101 to the chuck in association with a driving spindle 11 and a single passage swivel joint 102, The single passage swivel joint is relatively small in structure and can be accommodated within the interior of the driving spindle.

What is claimed is:

1. A fluid-distributing valve unit comprising a valve block having a valve bore, the bore having an inlet end adapted for connection with a pressure fluid supply line and having an exhaust end opening out of the block, an annular row of equally spaced ports opening in a common plane through the block from the midarea of the bore, a shuttle valve operable in the bore having an annular row of equally spaced ports opening through the body of the valve in a common plane, each alternate ports in the valve having constant communication with the inlet end of the bore and each other ports in the valve having constant communication with the exhaust end of the bore, a spring biasing the valve to a normal position at the inlet end of the bore in which the several ports in the valve are axially removed from and a predetermined degree angularly out of phase with the ports of the bore, the valve being adapted each time upon application of inlet pressure fluid to the inlet end of the bore to move axially from its normal position to the exhaust end of the bore, cam means at the exhaust end of the bore having cooperation with complementary cam means on a corresponding end of the valve to advance the valve angularly a predetermined degree upon said axial movement of the valve so as to bring the alternate ports in register with some of the ports in midarea of the bore and to bring the other ports of the valve in register with the remaining ports in the midarea of the bore, the spring being responsive to relaxation of the pressure of said inlet fluid to return the valve axially to the inlet end of the bore, and cam means at the inlet end of the bore having cooperation with complementary cam means on a corresponding end of the valve to advance the valve angularly said predetermined degree from its last angularly advanced condition.

2. A fluid-distributing valve unit as in claim 1, wherein the cam means at the ends of the bore for producing angular advance of the valve are contained entirely within the bore.

3. A fluid-distributing valve unit as in claim 1, wherein the ports opening through the block from the midarea of the bore are four in number spaced apart, the ports opening through the body of the valve are four in number spaced 90 apart.

4. A fluid distributing valve unit as in claim 3, wherein the alternate ports are diametrically opposed and the other ports in the valve are similarly opposed, and an opposed pair of the ports opening through the block are adapted for connection to a chamber, and the remaining pair of opposed ports opening through the block are adapted for connection to a separate chamber.

5. A fluid-distributing valve unit as in claim I, wherein the cam means at the exhaust end of the bore has a group of axially extending cam fingers spaced circumferentially equally apart each finger having a cam surface declining angularly in a particular direction, the cam means at the inlet end of the bore has an oppositely extending group of similar cam fingers, each finger of which has a cam surface declining angularly in an opposite direction, and the cam surfaces of the fingers at the inlet end of the bore being advanced angularly out of phase a predetermined degree from the cam fingers at the exhaust end of the bore.

6. A fluid-distributing valve unit including a valve block (38) having a valve bore (65), an inlet end (93) of the bore adapted for connection with a pressure fluid supply line, an opposite exhaust end (96) of the bore having communication with a vent (53), a group of ports (98, 99) opening out of the midarea of the bore, a valve (68) axially slidable in the bore, the valve having a nonnal position (FIG. 8) blocking the group of ports from the inlet end of the bore, the valve being slidable from its normal position to the opposite end of the bore upon application of pressure fluid to the inlet end of the bore, a spring (85) responsive to relief of such pressure fluid from the inlet end of the bore to return the valve to its normal position, cam means (67) at the exhaust end of the bore having cooperation with the valve each time the valve is moved axially from its normal position to advance the valve angularly a predetermined degree, cam means (66) at the inlet end of the bore having cooperation with the valve each time it is returned axially to its normal position to further advance the valve angularly a similar predetermined degree, the valve having a group of ports (89, 94) opening through the midarea of its body each alternate one of which is in constant communication with the inlet end of the bore and each other one of which is in communication with the exhaust end of the bore, the extent of axial movement of the valve from its normal position and the degree of said angular movement being such that each time the valve is so moved each of the ports (89, 94) of the valve is successively brought into register with a separate and different one of the group of ports (98, 99) opening out of the midarea of the bore.

i i i i i

Claims

1. A fluid-distributing valve unit comprising a valve block having a valve bore, the bore having an inlet end adapted for connection with a pressure fluid supply line and having an exhaust end opening out of the block, an annular row of equally spaced ports opening in a common plane through the block from the midarea of the bore, a shuttle valve operable in the bore having an annular row of equally spaced ports opening through the body of the valve in a common plane, each alternate port in the valve having constant communication with the inlet end of the bore and each other port in the valve having constant communication with the exhaust end of the bore, a spring biasing the valve to a normal position at the inlet end of the bore in which the several ports in the valve are axially removed from and a predetermined degree angularly out of phase with the ports of the bore, the valve being adapted each time upon application of inlet pressure fluid to the inlet end of the bore to move axially from its normal position to the exhaust end of the bore, cam means at the exhaust end of the bore having cooperation with complementary cam means on a corresponding end of the valve to advance the valve angularly a predetermined degree upon said axial movemenT of the valve so as to bring the alternate ports in register with some of the ports in midarea of the bore and to bring the other ports of the valve in register with the remaining ports in the midarea of the bore, the spring being responsive to relaxation of the pressure of said inlet fluid to return the valve axially to the inlet end of the bore, and cam means at the inlet end of the bore having cooperation with complementary cam means on a corresponding end of the valve to advance the valve angularly said predetermined degree from its last angularly advanced condition.

3. A fluid-distributing valve unit as in claim 1, wherein the ports opening through the block from the midarea of the bore are four in number spaced 90* apart, the ports opening through the body of the valve are four in number spaced 90* apart.

4. A fluid-distributing valve unit as in claim 3, wherein the alternate ports are diametrically opposed and the other ports in the valve are similarly opposed, and an opposed pair of the ports opening through the block are adapted for connection to a chamber, and the remaining pair of opposed ports opening through the block are adapted for connection to a separate chamber.

5. A fluid-distributing valve unit as in claim l, wherein the cam means at the exhaust end of the bore has a group of axially extending cam fingers spaced circumferentially equally apart each finger having a cam surface declining angularly in a particular direction, the cam means at the inlet end of the bore has an oppositely extending group of similar cam fingers, each finger of which has a cam surface declining angularly in an opposite direction, and the cam surfaces of the fingers at the inlet end of the bore being advanced angularly out of phase a predetermined degree from the cam fingers at the exhaust end of the bore.

6. A fluid-distributing valve unit including a valve block (38) having a valve bore (65), an inlet end (93) of the bore adapted for connection with a pressure fluid supply line, an opposite exhaust end (96) of the bore having communication with a vent (53), a group of ports (98, 99) opening out of the midarea of the bore, a valve (68) axially slidable in the bore, the valve having a normal position (FIG. 8) blocking the group of ports from the inlet end of the bore, the valve being slidable from its normal position to the opposite end of the bore upon application of pressure fluid to the inlet end of the bore, a spring (85) responsive to relief of such pressure fluid from the inlet end of the bore to return the valve to its normal position, cam means (67) at the exhaust end of the bore having cooperation with the valve each time the valve is moved axially from its normal position to advance the valve angularly a predetermined degree, cam means (66) at the inlet end of the bore having cooperation with the valve each time it is returned axially to its normal position to further advance the valve angularly a similar predetermined degree, the valve having a group of ports (89, 94) opening through the midarea of its body each alternate one of which is in constant communication with the inlet end of the bore and each other one of which is in communication with the exhaust end of the bore, the extent of axial movement of the valve from its normal position and the degree of said angular movement being such that each time the valve is so moved each of the ports (89, 94) of the valve is successively brought into register with a separate and different one of the group of ports (98, 99) opening out of the midarea of the bore.