US2914292A - Tracer valve - Google Patents

Description

Nov. 24, 1959 A. ANDERSON TRACER VALVE Filed Aug. 27. 1956 v fm1/n for* e lrzdensoft, w ,I a uw j) jfl/Wwf Patented Nov. 24, 1959 TRACER VALVE Axel Anderson, Rockford, Ill., assigner to Sundstrand Corporation, a corporation 'of Illinois Application August 27, 1956, Serial No. 606,512

4 Claims. (Cl. 251-3) This invention relates to valves and, more particularly, to a tracer valve.

It is the general object of this invention to provide a new and improved tracer valve. l

A more specilic object of this invention isY to provide a new and improved tracer valve wherein a longitudinally movable valve member is responsive to lateral pressure applied to a stylus disposed substantially in alignment therewith to move the valve member in one direction.

Another object of this invention is to provide such a tracer valve wherein the valve member isv slidable ina sleeve having a plurality of liuid ports and passages formed therein, wherein resilient means are provided to urge the valve member in the other direction and wherein the stylus is carried in a valve stempivotally mounted in the end of the sleeve so that pivotable movement of the valve stem causes movement of the valve member to control the ow of liuid through the ports and passages formed in the sleeve.

Another object of the invention is to provide a new and improved tracer valve of the character describedwherein a pin carried in the valve stem adjacent the pivotal mounting thereof is engageable with a slotted portion of the sleeve so as to prevent rotation of the valve stem and the stylus with respect to the sleeve, thus insur bodiment of the invention taken generally along line 1 1` of Fig. 2;

Fig. la is an enlarged fragmentary View of Fig. l show ing-the pivotal connection between the Valve stem and the retainer;

Fig. lb is an enlarged fragmentary vertical sectional view taken generally along line 1b`1b of Fig. 1;

Fig. 2 is a horizontal sectional view taken generally along line 2-2 of Fig. l;

Fig. 3 is a top plan view of Fig. 1 with the cover removed;

Fig. 4 is a vertical sectional view on a reduced scale taken generally along line 4--4 of Fig. 2; and

Fig. 5 is a vertical sectional view on a reduced scale taken generally along line 5 5v of Fig. 2.

While the invention herein described is a preferred embodiment, it is not intended to limit the invention to the specic form and arrangement shown, it being contemplated that various changes may be made by those skilled in the art without departing from the spirit and scope of the appended claims.

Referring to the drawings for a description of a preferred embodiment of the invention, the tracer valve in cludes a hollow sleeve or housing 10 having a reduced end portion 11. A bore 10 extends through the housing. A transverse passage 12 is adapted to be connected at its outer. end to a source of fluid under pressure, and at its inner end connects with an annular groove 16 around the central position of the bore 10. A transverse passage 13 is adapted to be connected at its outer end to a lluid reservoir and at its inner end to anV annular groove 17 in the bore 10 spaced below the groove 16. A pair of transverse passages 14 and 15 are adapted to be connected at their outer ends to a cylinder and piston device to be controlled. As shown in the drawings, the passages 14 and 15 extendthrough` the housing wall andopen into the bore 10 on opposite sides ofthe groove 16. An internal annular groove 18 formed in the bore 10 is also adaptedy to be connected to the fluid reservoir through a lateral bore 19'and ablongitudinal bore 20 (both of which have their outer ends plugged), as shown in Fig. 4.

In order to control the ow of fluid through the passages described, a valve member 25 having lands 26, 27 and 28 is slidable in the bore 10. As shown in Fig. l, the lands are spaced apart the same as the groovesl 18, 16 andV 17 respectively. Land 27 serves to control the flow of fluid from pressure passage 12 to the cylinder passages 14 and 15, whereas the lands 26 and 2S control the return of fluid from the cylinder passages to the reservoir passage 13. Movement of the valve member25 iscontrolled by a valve stem 29 disposed in the reduced` end portion 11 of the housing and universally pivotally mounted in a retainer or mounting member 30'threadably mounted in the end of the housing. The valve stem 29 has a semi-spherical surface 31 riding on an internal conical surface 32 formed on the retainer 30, as best shown in Fig. la. The valve stem 29 is pivotable upon a lateral pressure being applied to a stylus 33 which eX- tends axially from the valve stem 29 and is secured therein by a set screw 34. To convert the pivotal movement of the valve stem 29 to longitudinal movement of the valve member 25, a single relatively large ball 35is disposed between adjacent ends of the valve member 25 and thevalve stem 29, the ball 35 being disposed in opposing conical recesses 36 and 37 formed respectively in the ends of the valve member 25 and the valve stem 29.

The valve member 25 is constantly urged downwardly by a relatively weak spring 39 which is mounted in a |bore 40 formed in the upper end of the valve member. 25, the spring 39 acting against a snap ring 41 mounted in the bore 40. and against a valve cap y42 secured against the upper end ofthe housing 10 by bolts 43.

During normal tracing operation, the valve memberV 25 is controlled solely by the spring 39 and the stylus 33.

When the stylus 33 reaches a depression lin a template (not shown) the spring 39 is operable to urge the valve member 25 downwardly so as to align the valve stem 29 with the Valve member 25, as shown in Fig. l, and thus shift valve member to the olf-center position whereinl pressure fluid from groove 16 flows out the cylinder passage 14 (which in accordance with well known practice would cause the piston in the cylinder to move the tracer valve toward the template). When the stylus 33 reaches a projecting portion of the template, it will be pivoted` to a greater angle than that of its neutral position so as to shift the valve member 25 upwardly and thus pass pressure uid from groove 16 to cylinder passage 15 and cause shift of the tracer valve away from the template.

It is believed apparent with such a valve construction that if the valve stem 329 is freely rotatable in the retainer 30, the accuracy of the tracer valve would be greatly decreased should the stylus 33 ever become bent out of alignment with the valve stern 29. Instead of the valve stern 29 pivoting purely in response to the surface variations in the template, any rotation of the olf-center stylus would result in erroneous pivoting movement of the valve stern 29. To insure maximum accuracy of this tracer valve, means have been provided to prevent rotation of the valve stem 29 in the retainer 30 while permitting universal pivoting movement of the valve stern 29. As shown in Figs. l and 1b, this means includes a pin 44 which is tightly fitted in a bore 45 formed in the valve stern 29 and which has end portions 46 extending radially from the valve sterny 29 and engageable in vertical slots 47 formed in the retainer 30.

In order to provide means for rapidly retracting the valve member 25 to an upper position in which pressure uid flows out cylinder passage 15, a solenoid indicated generally at 48 is provided. The solenoid 48 includes a block 49 having an integral plate 49a secured against the valve cap 42 by bolts 42a. The block 49 has a bore 50 formed therein in alignment with the valve member 25 and a cylindrical coil 51 mounted on the block 49 with a plunger 52 disposed therein. The end of the plunger 52 abuts against a push pin 53 slidable in the bore 50 which in turn abuts against the end of a rod member 54 which is slidably mounted in a bore 55 formed in the valve cap 42 and has a head portion 56 held loosely captive in the bore 40 in the end lof the valve member 25 by the snap ring 41. A relatively strong compression spring 57 acting between the valve cap 42 and a spring retainer 58 pinned to the rod member 54 acts to move the valve member 25 upwardly when the solenoid is de-energizcd. As seen in Fig. 3, leads 69 for the solenoid coil 51 pass through openings in the valve cap 42 and into a flexible conduit 70 mounted in an opening in the valve cap 42.

During normal operation of the tracer valve, the solenoid 48 is energized thus holding the plunger 52 downwardly of the coil 51 as shown in Fig. 1, and maintaining the rod member 54 in the position shown, thus neutralizing the action of the spring 57 and allowing the valve member 25 to be controlled solely by the stylus 33 and the spring 39. When it is desired to shift the valve member 25 upwardly, independently of actuation of the stylus 33, the solenoid 48 is de-energized, thus permitting the spring 57 to move the rod member 54 and plunger 52 upwardly so that the head 56 of the rod member 54 engages the snap ring 41 and lifts the valve member 25 upwardly.

As shown in Fig. l, a cover member 60 enclosing the solenoid 48 is fitted over the valve cap 42 and against the housing 1G so as to provide an extension of the housing 10. As it may be desirable to advance the stylus 33 without energizing the solenoid 48 as when setting up a job, a manual button 61 is mounted in an opening in the end of the cover member 60. When the button is depressed against the plunger 52, the rod member 54 is moved downwardly so as to neutralize the spring 57 and allow the valve member 25 to be controlled by the spring 39, thus moving the stylus 33 to the position of Fig. l.

As shown in Fig. l, the valve member 25 is hollow, having a relatively large longitudinal bore 63 formed therein communicating at one end with the bore 40 and at the other end with the conical recess 36 through Va reduced passage 64. By hollowing out the valve member 25, its weight is substantially reduced so as to reduce serious shocks when the valve oscillates on high frequency. which may be a common occurrence in tracer valves. The hollow valve member 25 also permits fluid leaking around the valve member 25 to reach the single ball 35 and the valve stem pivoting surfaces 31 and 32 to provide lubrication of these moving parts.

vA vacuum opening 66 (shown 90 out of position in Fig. 1) formed in the end of the reduced end portion 11 of the housing 10 communicates through a chamber 67 in the reduced end portion 11 of the housing 10 with a longitudinally extending passage 68, best shown in Figs. 2 and 5, formed in the housing 10 and opening at the other -end between the end of the housing 10 and the valve cap 42. This vacuum system is adapted to be connected to a vacuum device, at the opening 66, so that excess fluid may be drained from the valve to prevent a build up of uid pressure at either end of the valve member 25 which could affect the operation thereof.

Thus there is disclosed a compact and simplified tracer valve having means for rapidly reh'acting the valve member when desired, which comprises a relatively small number of parts and which is very efficient, sensitive and accurate in operation. This tracer valve also provides automatic retraction of the stylus and an associated cutting tool in the event of a power failure.

I claim:

1. A tracer valve, comprising, a valve housing having a longitudinal valve bore, a generally cylindrical valve member slidable in the valve bore and having external formations to control the ow of uid between fluid passages communicating with the valve bore and having a Vcentral longitudinal recess therethrough providing a hollow, light weight construction, a template engaging stylus movably mounted in one end of the housing for effecting longitudinal movement of the valve member in one direction, away from said one lend of the housing, an end cap closing the other end of the valve housing, a snap ring positioned in the valve member recess, a first spring bearing against the end cap and the snap ring urging the valve member in the opposite direction, and selectively operable means independent of the valve member for moving the valve member in said one direction in opposition to said first spring including a valve actuating rod reciprocable in the end cap relative to the valve member, said rod having an inner end positioned in the valve member recess and an outer end positioned outside the housing, a head on the inner end of the rod engageable with the snap ring for moving the valve stern in said one direction, a second spring stronger than the first spring connected to the outer end of the rod for moving the rod in said one direction to engage the head and snap ring to thereby move the valve member in said one direction in opposition to the lirst spring, and means engageable with the rod adjacent the outer end thereof for moving the rod in said opposite direction to compress the second spring and disengage said head and snap ring.

2. A tracer valve, comprising, a valve housing having a longitudinal valve bore, a valve member slidable in the valve bore for controlling uid flow between uid passages communicating with the valve bore, a template engaging stylus movably mounted in one end of the housing for effecting longitudinal movement of the valve member in one direction, away from said one end of the housing, an end cap closing the other end of the housing, a first spring bearing between the end cap and the valve member urging the latter in the opposite direction, and selectively operable means separate from the valve member for moving the valve member in said one direction in opposition to said first spring, including a rod longitudinally reciprocable in the end cap relative to the valve member and having an outer end outside the housing and an inner end within the housing engageable with the valve member to move the valve member in said one direction, a second spring stronger than the first bearing against the end cap and the outer end of the rod urging the rod in said one direction, a solenoid having a reciprocable plunger movable against the rod when the solenoid is energized to compress the second spring and disengage the inner end of the rod from the valve member to free the valve member for control by the first spring and the stylus, said solenoid when deenergized releasing the plunger to permit movement of the rod and valve member in said one direction under urge of the second stronger spring.

3. A tracer valve, comprising, a valve housing having a longitudinal valve bore, a generally cylindrical valve member slidable in the valve bore and having external formations to control the ow of fluid between fluid passages communicating with the valve bore and having a central longitudinal recess therethrough providing a hollow, light weight construction, a template engaging stylus movably mounted in one end of the housing for eifecting longitudinal movement of the valve member in one direction, away from said one end of the housing, an end cap closing the other end of the valve housing, a snap ring positioned in the valve member recess, a spring bearing against the end cap and the snap ring urging the valve member in the opposite direction, and selectively operable means independent of the valve member for moving the valve member in said one direction in opposition to said spring including a valve actuating rod reciprocable in the end caprelative to the valve member, said rod having an inner end positioned in the valve member recess and an outer end positioned outside the housing, a head on the inner end of the rod engageable with the snap ring for moving the valve stem, a head on the outer end of the rod, a second spring stronger than the iirst bearing against the outer head and the end cap urging the rod in said one direction, a solenoid having a reciprocable plunger movable against the outer end of the rod on energization of the solenoid to move the rod in said opposite direction compressing the second spring and disengaging the inner head and snap ring to free the valve member for control by the first spring and the stylus, the solenoid when deenergized releasing the plunger to permit movement of the rod and valve member in said one direction under urge of the second stronger spring, and a manually depressible button for moving the solenoid plunger against the rod to compress the second spring when the solenoid is deenergized.

4. A tracer valve comprising, a valve housing having a longitudinal bore therein, a valve member slidable in the bore for controlling fluid ow between fluid passages communicating with the bore, a template engaging stylus movably mounted in one end of the housing for eecting longitudinal movement of the valve member in one direction, away from said one end of the housing, a rst spring means urging the valve member in the opposite direction, and selectively operable means separate from the valve member for moving the valve member in said one direction in opposition to said rst spring means, including an actuating rod longitudinally reciprocable in the opposite end of the housing relative to the valve member and having an outer end outside the housing and an inner end within the housing having a lost motion connection with the valve member to move the latter in said one direction, second spring means stronger than the rst urging the rod in said one direction, a solenoid having a plunger movable against the outer end of the rod when the solenoid is energized to overcome the second spring means and disengage the inner end of the rod from the valve member for control by the first spring means and the stylus.

References Cited in the le of this patent UNITED STATES PATENTS 2,083,774 Campbell June 15, 1937 2,586,654 Hoelscher Feb. 19, 1952 2,726,582 Roehm Dec. 13, 1955 2,731,980 Diefenderfer Jan. 24, 1956 2,743,584 Rosebrook May 1, 1956 FOREIGN PATENTS 354,819 Germany 1.... of 1922 503,968 Canada of 1954

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