US3814128A - Valve assembly having an actuator with a camming ball - Google Patents

Abstract

A valve in which the valve member is operable by a tappet means, the tappet means being lifted by a ball which is guided to roll on a plate under the tappet and thereby lift the tappet.

Description

United States Patent 11 1 A L 11-11 Grantham VALVE ASSEMBLY HAVING AN ACTUATOR WITH A CAMMING BALL [75] Inventor:

[22] Filed:

[73] Assigneez Tecalemit (Engineering) Ltd 2,289,783 7/1942 H011 137/6361! Devon, England FOREIGN PATENTS OR APPLlCATlQNS 521,182 7/1953 Belgium 251/263 May 7 2/1961 France 137/6361 21 1 Appl. No.: 253,553

30 Foreign Application PriorityData May 17, 1971 Great Britain 15300/71 I [52] U S CI 137/624 13 74/56 137/596 2 A valve in which-the valve member is operable by a "1'37/624 3 5 5 tappet means, the tappet means being lifted by a ball [5]] 1m Cl l 31/524 Whichis guided to roll on a plate under the tappet and [58] Field ofSearch 137/6361, 624.13, 624518, 137/5962 ,27.5; 251/229, 251-258, 262,

Max Edward Grantham, Plymouth [56] References Cited Devon, England Primary E,\ aminerA1an Cohan Assistant ExaminerRichard Gerard thereby lift the tappeL.

[ June 4, 1974 UNITED STATES PATENTS 10 Claims, 2 Drawing Figures 1' VALVE ASSEMBLY HAVING AN ACTUATOR e WITH A CAMMING BALL BACKGROUND OF QTHEINVENTION The present invention relates to valves. Many valves are operated by cams of various kinds but the usual cam suffers from the severe disadvantage that the cam surface wears out rapidly under conditions of continuous use despite the use of very hard surfaces'and lubrication.

SUMMARY OF THE INVENTION It is an object of the invention to provide a valve in which wear in the valve operating mechanism is considerably reduced. w 1 1 The present invention-provides a valve comprising a valve body, a valve member, a tappet means, movement of which'is operable to open and close the valve, andmeans for moving the tappet means from a rest po sition against a bias, said means for movingthe tappet means comprising a plate fixed in relation to the valve body and spacedffrom the tappet means in its rest position, a rotatable member, a ball retaining part of said rotatable member passing between the tappet means and the plate as the rotatable member rotates and a ball retained in said balliretaining partand constrained to roll against the plate, the diameter of the ball being greater than the distance between the plate and the tappet means-in its rest position, so that as the rotatable member rotates and the ball passes betwe'enthe tappet means and the plate,the ball moves the tappet means from its rest position against the bias.

In this way, since the ball rolls as it crosses the-plate, a different part of the ball is presented to the tappet means each time it contacts the tappet means and this considerably reduces wear. Also thejvalve is readily adapted to provide lubrication of the tappet means since if a lubricant is arranged to be present on the surface of the plate, then as the ball rolls on the plate lubricant is picked up by the surface of the ball and is transferred thereby to the tappet means.

In a preferred arrangement, the tappet means and the valve member are integral and preferably, if the valve member is in the form of a valve poppet, the stern of the poppet constitutes the tappet means. The rotatable member may bein the form of a rotatable plate arranged parallel to said fixed plate andin this case the ball-retaining part may be formed to provide a circular hole through the rotatable plate.

The rotatable plate may be circular having teeth on its periphery engaged by a drivable worm.

The ball is preferably of a harder material than that of the tappet means, such as glass-or steel. 7

The means for moving the tappet means may include I more than one ball situated in respectiveball retaining parts of the rotatable member, the diameterof each ball being greater than the distance between the plate and the tappet means in its rest position; The ball(s) may move more than one tappet means in each-rotation of the rotatable member, the distance between the plate and each tappet means in its rest position being The invention also provides an air control valve for alternately supplying air from an air supply to an outlet and communicating said outlet withian exhaust comprising a valve as aforesaid in which the ball moves two tappet means connected to two respective separate valve members during each rotation of the rotatable member, one of the two tappet means operating a valve member controlling communicationbetween the air supply and the outlet andv the other of the two tappet means operating a valve member controlling communication between theoutlet and the exhaust. Y

Two air control valves embodying preferred forms of the invention and which are arranged to beused'in a system such as that shown inour British Patent No. 1,105,383 will now be described byway of example and with reference to the accompanying drawings in which: i

FIG. 1 shows a diagrammatic cross-section through a first air control valve, and a FIG. 2 shows a diagrammatic cross-section through a second aircontr ol valve.

In both drawings the same reference numerals have been used for corresponding parts.

' Theair control valve comprises a valve body 11 hav-. ing an inlet port l2,'an outlet port 13 and an exhaust port 14. The inlet port is connected to a supply of air (which may be via an air safety valve such as shown in British Patent No. 1,105,383), andthe outlet port 13 may be connected to a pump unit such as the piston.

formed in' a threaded plug 15 screwed into the valve bodyg-ll, a bore. lfi'through the plug 15 communicating with a coaxial bore 17 in the valve body 11. A valve member in the form of a first valve poppet 18 closes a port 19 in the base of the bore 17, the head-20 of the valve poppet 18 being situated within the bore "and the stem 21 extending through the port 19. The surface of the head 20facing the inlet port 12 includes ashoulder 22, a biassing spring 23 acting between the shoulder 22 and a shoulder formed by the end of the plug 15 fonned since the diameter of the bore 16 is less than the diameterof the bore 17 where the two bores meet.

The head 20 of the poppet 18 carries, in an annular valve poppet 30 biassed closed by a spring 33 having a stem 32. The coaxial bores 16, 17 and the coaxial bores 27, 28 areparallel to one another as are the axes of the poppets 18, 30. It will be noted' that the arrangement 7 of the valve poppet 30 is identical to the arrangment of the'valve poppet l8 and .willnot be further described. A passage 31 communicates the side of port 19 opposite bore 17 with the bore 28. above the poppet 30. The

port 29 communicates on the side opposite the bore 28 with the exhaust port 14.

The poppets 18, 30 are operated by means arranged to lift the stems 21, 32 respectively of the two poppets 18, 30 and thereby lift the poppets 18, 30 from their restposition against the bias of the springs 23, 33 respectively, This means comprises a circular rotatable Patent No. 1,105,383/

plate 34 havinga circular hole 43 retaining a ball 35 of glass which rolls over a fixed plate 36 closing a chamber 37 within which the ball 35 and plate 34 are situated. Theball 35 is a loose fit within hole 43 so'as to allow it to roll freely. The valvestems 21, 32 extend into thechamber 37 through the side of the chamber opposite the plate 36,-the part of the valve stems 21, 32 extending into the'chamber 37 forming tappets. The stems 32,- 21 are guided by valvejguides 38, 39 respectively and are sealed with respect to their valve guides 38, 39 by means of sealing O- rings 40, 41 respectively.

The plates and 36 are parallel to one another, the valve stems 21, 32 being arranged perpendicular to these plates. The rotatable plate 34 is constrained to rotate about an axis perpendicular thereto by a pin 42 extending therethrou gh the pin 42 being mounted between the valve body 11 and the plate 36. The circular hole 43 through the rotatable plate .34.retains the ball and constrains it to move with the rotatable plate as the rotatable plate 34 rotates about the pin 42. The hole 43 is-situated in the plate such that as the plate 34 rotates the ball-35 passes directly under the valve stems 21, 32 in turn and, as can be clearly'seen from-FIG. 1, the ball 35 cannot escape from the hole 43 since the plate 36 is spaced from the other side of the chamber 37.by a

1 distance which is only slightly greater than the diameter of the ball 35. The. stems 21, 32 protrude into the chamber, 37 man extent such that the distance between the lower end of thestemsZl, 32and theplate 36 is less than the diameter of the ball 35,

The rotatable plate 34 is circular and-has around its outer edge teeth 44 which mesh with a worm (not shown) driven by the spindle 4 5.

The'operation of the air control valve is as follows. The spindle 45 is rotated which rotates the worm and the teeth 44, the rotatable plate 34 thereby rotating about the pin 42. When the ball 35 is not contacting either of the stems 21 or 32 the poppets 30, 18 are in their closed or restposition in which case no air passes from the inlet port 12, nor is any air allowed to pass from or to the outlet port 13.

As the rotatable plate 34 rotates, the ball 35 is moved so as to pass between the plate36 and the valve stem 21 which lifts the valve stem 21 against the bias of spring 23 as the distance between the valve stem and the plate 36 is less than the diameter of the ball 35. It will be appreciated that although there is sliding of the lower surface of the valve stem 21 over the surface of the ball 35, (and possibly, sliding of the surface of the plate 36 over the surface of the ball 35 ),'as the ball has been rotating over the plate 36 before contacting the valve stem 21, a different part of the surface of the ball a 35 is presented to the valve stem 21 each time the surface of the ball 35 contacts the stem21, and to the sur- As the plate 34 continues to rotate the ball 35 passes out of contact with-the valve stem 21 and hence the poppet 18 closes. it will thus be seen that a pulse of air has been directed to the chassis lubricator unit. The

plate 34 continues to rotate and the ball 35 passes be tween the plate 36 and the valve stem 32 to unseal the poppet 30 by lifting the valve stem 32 and moving the poppet 30 against the bias of spring 33.-The' unsealing of, poppet 30 allows air to pass from the chassis lubricator unit through the bores 27, 28, through the port 29 and to the exhaust port l4.

The plate 34 continues to rotate and it-will be seen that the poppets 18, 30 may be opened alternately for temately.

face of the plate 36each time the surface slides over the surface of the ball 35, so that any wear is distributed over the whole of the surface of the ball 35. This is in contrast to the use of a normal 'cam in which the same part of the cam surface contacts the valve stem each time and hence rapidly wears.

I from the inlet port 12 via the bores l6, 17 past the poppet 18 through the portl9 and into the passage 31 to the bores 28 and 27 and hence out of the outlet port 13 to, for example, the chassis lubricator unit of British Advantages of this layout have been mentioned above such as the reduction in wear of .the cam surfaces since the ball 35 presents a different surface each time it contacts the valve stems 21, 32 and there are further advantages in that if a small quantityof lubricant is situated on the plate 36, this lubricant will be picked up by the ball surface as it rotates and deposited on the valve stems2l, 32 which will thereby-lubricate the valve stems 21, 32 as they move in their valve guides 39, 38.

Also the valve stems 21, 32 are of a material suchas brass tolerant of abrasion where this occurs through lu-v brication-deficiency and the ball 35 ,isofaknown and reliable surface finish and relativelyve'ry hard, and substantially does notrwear and willnot absorb the wear 7 debris of the valve stems; this would, if allowed, accelerate the wear process. in this way little wear occurs.

. The air control valve of FIG. 2 is similar in most respects to. the air control valve of FIG. '1. However, in

this case, the pin 42 is mountedfixedly in the plate 36 of plate 34. Also, the method of driving the rotatable plate 34 might be different, the rotatable shaft 34 being driven directly by a rotating shaft. In many applications it will not be necessary to interconnect the poppets 18, 30 in the way shown in the present example but the valve members can operate completely independently to open and close associated inlet and outlet ports 12 andl3. g Y

Also the valve members might not be operated by the ball '35 acting directly on the valve stems 21,32 but a separate tappet member might be used. Also, the plate 34-need not be a complete plate but could be a cage,

it only being necessary for it to have some means for retaining the ball 35 and rotating it about an axis spaced from the ball 35.

I claim:

v l. A valve comprising a valve body, a valve member, a tappet means, movement of which is operable to open and close the'valve, and means for moving the tappet means from a rest position against a bias, said means formoving the tappet means comprising a plate fixed in relation to the valve body and spaced from the tappet means in its rest position, a rotatable member, a ball-retaining part of said rotatable member passing between the tappet means and the plate as the rotatable member rotates and a ball retained in said ballretaining part and constrained to roll in a plane against the plate, the radius of the ball being greater than the distance between the tappet means in its rest position and the plane in which the centre of the ball travels, so that as the rotatable member rotates and the ball passes between the tappet means and the plate, the ball moves the tappet means from its rest position against the bias.

,retaining part is formed to provide a circular hole through the rotatable plate.

6. A valve as claimed in claim 4 in which the rotatable plate is circular and has teeth on its periphery en gageable by a rotating worm.

7. A valve as claimed in claim 1 in which the ball is of a harder material than that of the tappet means.

8. A valve as claimed in claim 1 including a plurality of said tappet means, said ball being operable to engage and move more than one of said tappet means in each rotation of said rotatable member, the distance between each associated tappet means in its rest position and the plane in which the centre of said ball travels being less than the radius of said ball.

9. A valve as claimed in claim 8 including a plurality of separate valve members actuated ny said tappet means during each rotation of the rotatable member.

10. In combination, a fluid control valve in accordance with claim 8 for alternately supplying air from an air supply to an outlet and communicating said outlet with an exhaust, passage means in said body in communication with one of said valve members operated by one of said tappet means for controlling communication between said air supply and said outlet and second passage means in said valve body in communication with another of said valve members operated by another of said tappet means for controlling communication between said outlet and said exhaust.

Claims (10)

1. A valve comprising a valve body, a valve member, a tappet means, movement of which is operable to open and close the valve, and means for moving the tappet means from a rest position against a bias, said means for moving the tappet means comprising a plate fixed in relation to the valve body and spaced from the tappet means in its rest position, a rotatable member, a ballretaining part of said rotatable member passing between the tappet means and the plate as the rotatable member rotates and a ball retained in said ball-retaining part and constrained to roll in a plane against the plate, the radius of the ball being greater than the distance between the tappet means in its rest position and the plane in which the centre of the ball travels, so that as the rotatable member rotates and the ball passes between the tappet means and the plate, the ball moves the tappet means from its rest position against the bias.

2. A valve as claimed in claim 1 in which the tappet means and the valve member are integral.

3. A valve as claimed in claim 2 in which the valve member is in the form of a valve poppet and the stem of the poppet constitutes the tappet means.

4. A valve as claimed in claim 1 in which the rotatable member is in the form of a rotatable plate arranged parallel to said fixed plate.

5. A valve as claimed in claim 4 in which the ball-retaining part is formed to provide a circular hole through the rotatable plate.

6. A valve as claimed in claim 4 in which the rotatable plate is circular and has teeth on its periphery engageable by a rotating worm.

7. A valve as claimed in claim 1 in which the ball is of a harder material than that of the tappet means.

8. A valve as claimed in claim 1 including a plurality of said tappet means, said ball being operable to engage and move more than one of said tappet means in each rotation of said rotatable member, the distance between each associated tappet means in its rest position and the plane in which the centre of said ball travels being less than the radius of said ball.

9. A valve as claimed in claim 8 incLuding a plurality of separate valve members actuated ny said tappet means during each rotation of the rotatable member.

10. In combination, a fluid control valve in accordance with claim 8 for alternately supplying air from an air supply to an outlet and communicating said outlet with an exhaust, passage means in said body in communication with one of said valve members operated by one of said tappet means for controlling communication between said air supply and said outlet and second passage means in said valve body in communication with another of said valve members operated by another of said tappet means for controlling communication between said outlet and said exhaust.

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