US3515369A - Fast acting valve - Google Patents

Description

June 2, 1970 -l. ABERS 3,515,369

FAST ACTING VALVE Filed No v. 24, 1967 38 I 40 INVENTOR L ILGONIS ABER I BY ATTORNEY United States Patent 3,515,369 FAST ACTING VALVE Ilgonis Abers, Exeter, N.H., assignor to Ion Physics Corporation, Burlington, Mass, a corporation of Delaware Filed Nov. 24, 1967, Ser. No. 685,521 Int. Cl. F16k 31/44 US. Cl. 25175 5 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION The present invention relates generally to valves and more particularly to a new and improved valve that can close in less than milliseconds.

Valves, in general, are old and commonplace and their applications are many and varied. None of the known prior art valves have, however, been capable of progressing from fully open to fully closed in ten milliseconds or less. Indeed for most applications there is little necessity for such rapid closings.

With the advent of high energy electron beam machines and their utilization for material analysis it was found necessary that a valve be inserted in the beam path which could prevent debris and gases, created by the electron beam striking a target from returning along the beam path to the beam generator.

One such beam generation machine is known as a Flash X-ray System and is sold by the Ion Physics Corporation. This system comprises a high impedance multimegavolt supply which charges a gas insulated coaxial line separated from an evacuated field emission diode by a triggered pressurized gap. When the gap is triggered voltage build-up on the diode causes an intense electron beam to be generated. In most applications the diode is made to discharge through a thin metal foil covered window into a drift tube. This foil, in most cases, acts both as an anode seal (for the diode) and as a vacuum seal. After passing along the drift tube the beam is permitted to strike the target. Presently available equipment of this type can deliver a 5 nanosecond, 1 kilojoule beam whose peak power density exceed 10 watts/cm? Larger and more powerful machines are now being built.

This concentrated energy particularly adapts these machines for use in advanced research of material structure and for material testing. However, when such intense beams impinge on a body small solid particles are sometimes ejected with extensively high velocities. Certain of these particles return along the beam path with energies sufficient to rupture the foil covering the diode window. Since in most cases it is necessary to maintain a good vacuum in the diode rupture of the window destroys the vacuum and further permits gases, generated at the target to enter the diode. Condensation of such gases. on the diode walls can eventually lead to diode failure. At the present time repair or replacement of the foil requires an hours time and repair or replacement of the diode can require several days time. Thus a valve, between the diode and the target, which can close rapidly, so as to Patented June 2, 1970 prevent particles from striking the foil, becomes a necessity to prevent long periods of downtime.

The present invention was conceived in order to solve this problem.

SUMMARY OF THE INVENTION Broadly speaking the present invention is a valve which can close off a passageway in less than 10 milliseconds. More particularly the invention resides in a flapper, adapted to mate with a valve seat surrounding the passageway, which follows an arcuate path in closing. This flapper not only seals the passage, upon mating with the seal but may also be used to activate the beam.

DESCRIPTION OF THE DRAWINGS FIG. 1 shows a partially exploded view of a first embodiment of the invention.

FIG. 2 shows a partially broken away and exploded view of a different embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first embodiment of the invention and comprises an annular base plate 10 supporting a tubular beam passageway 11 mounted around the hole in the plate. The passageway 11 has its free end 12 positioned at a 45 angle with respect to the base 10 and to the beam path designated by arrow 13.

Affixed to plate 10, parallel to the beam axis, is a stationary post 14 at whose bottom there is provided a fixed surrounding insulating ring 15 adapted to carry an electrical trigger 16. Immediately above ring 15, on post 14, is a rotatable lower spring holder 17. Fixed to the top of post 14 a fixed distance from holder 17 is an upper spring holder 18. A helical spring 19 is placed between and permanently secured to the upper spring holder 18 and the lower spring holder 17.

A coupling 26 is rotatably mounted on the upper spring holder 18. This coupling carries on it a shaft 20 in line with post 14 and a gimbal 21. A flapper or gate 22 is fixedly mounted, by means of extension 23 and screws 24, on the rotatable lower spring holder 17. The gate 22 is permanently inclined at the same angle as seat 12 and when mated with seat 12 compress on O-ring 25 which is fitted on seat 12. Extension 23 also carries. on it, at its lower end, a trip arm 32 which juts out from extension 23 such that it interacts with trigger 16.

The gimbal 21 is a sleeve adapted to pivot around an axis perpendicular to the axis of the drive shaft 20. Two pivot points 27 and 28, apart, are provided on coupling 26. Springs 29 and 30 provided at the pivot points supply a positive force gimbal 21 so that a pro truding finger 31, provided on gimbal 21, will, when shaft 20 is rotated in a clockwise direction, engage gate 22 and drive it against spring 19..

This device operates as follows.

A rotational drive means such as a motor (not shown) is applied to drive shaft 20 to rotate coupling 26 in a clockwise direction around the axis of post 14. The gimbal fixed to coupling 26 rotates with it and its finger 31 engages gate 22 and drives the gate in the same direction. As gate 22 turns the lower spring holder 17 also turns to wind up spring 19. This continues until gate 22 begins to press against the back side of passageway 11.

As shaft 20 continues to turn the forces of springs 29 and 30 are overcome such that the tension sensitive gimbal finger 31 rides up over gate 22 releasing the gate. The wound spring 19 now begins to relax and drive the lower spring holder and gate 22 in a counter clockwise direction.

As the gate 22 moves in an arcuate path towards seat 12 the arm 32 strikes trigger 16. This can be used to generate an electrical signal which will activate the beam generation apparatus (not shown). In most applications the beam so generated is only about 5 nanoseconds in duration and is directed through passageway 11 in the direction of arrow 13 towards a suitable target (not shown). Gate 22 has meanwhile continued to move towards seat 12 and seats itself thereon within milliseconds after the beam has been initiated. This 10 millisecond time is faster than the time required for gases or explosion debries from reaching the passageway 11. Thus the passageway is sealed before debries can get into the passageway. In actual tests this described valve was found to operate the beam and close within 500 microseconds after initiation of the beam. This time being determined by measuring the time between contact of trigger 16 and seat 12.

The described embodiment was found to work quite well when passage 11 did not exceed /2 inch in diameter, however, when larger diameters were required, erg. above A2 inch, the design must be modified to assure good seating and reduce the effects of inertia and momentum.

A valve incorporating all the features of the invention which is suitable for sealing parts over /2 inch in diameter is shown in FIG. 2. For the sake of simplicity and ease of description, non-active items, such as the base, are not shown in this figure and only the essential portions of the apparatus critical to the operation are portrayed.

FIG. 2 shows a large diameter O-ring valve seat 39, set at a 75 angle on a tubular beam passageway 40. The tube 40 is supported on a base (not shown) which also carries an open box frame consisting of parallel sides 42 and 43 and a top 44. A post 45 is affixed to the base preferably by a floating bearing which allows several degrees of freedom so as to be parallel to the passageway 49 and a fixed distance therefrom. This post 45 carries close to its face end and in line with valve seat 39 a shutter mechanism adapted to seal off tube 40. This mechanism comprises a rotatable shutter bearing 46 attached to an extended shutter support 47 which maintains a shutter 50 in line with seat 39. By providing support 47 with a hemispherical recess and shutter 50 with a ball like protrusion a ball and socket arrangement that permits some latitude of movement between the shutter and the seat is achieved. The shutter is secured to the support by a bolt '48 and spring 49 combination.

A drive coupling 51 is rotatably mounted on the exposed free end of post 45' over the shutter bearing 46. This coupling may be directly or indirectly coupled to a rotary device such as an electric motor (not shown). This coupling is ringed by a gimbal 52 which is centrally pivoted on a pair of diametrically opposed pivot points 53, 54 located on coupling 51.

The gimbal 52 is provided with a downwardly projecting lip 55 which engages a shaft 56 extending from the shutter bearing 46 parallel to the shutter support 47. Additional strength and rigidity is provided this shaft by a support extension 57 affixed to support 47.

Positive engagement of lip 55 with shaft 56 is provided by an off-axis spring loading of the gimbal. This loading is effected by a compression spring 59 which fits into a recess 59 in coupling 51 and can engage a T-shaped mernber 60 provided at an off axis position on gimbal 52.

A trigger mechanism 62 is hung from the frame top 44 directly in line With the gimbal. This mechanism 62 extends a distance beneath the top 44 an amount calculated to apply a downward force to the gimbal such as to olfset and overcome the force exerted on the gimbal by spring 59. An electrical brush 63 is insulatedly held from top 44 parallel to trigger 62. Insulator 64 electrically isolates this brush brom the top 44. This brush 63 is aligned with the path that will be swept by shaft 56 as the shutter mechanism rotates about shaft 45. This brush provides a means whereby the shutter can be used to activate the beam generation apparatus. The top 44 is also provided 4 with an opening 65 which is in line with beam passageway 40 such that any beam traveling through the passageway 40 when the shutter 50 is open can continue out of the apparatus unimpeded.

The described valve operates as follows; when the coupling 51 is driven in a clockwise manner the gimbal 52, affixed thereto, also rotates. Because spring 59 provides a positive downward force on gimbal 52 the lip 55 picks up and engages shaft 56 so that the entire shutter mechanism being to rotate with the coupling as a single unit. If it is assumed that shutter 50 is initially sealed on seat 39 this rotary movement uncovers the beam passageway 40. As the shutter mechanism continues to rotate the shaft 56 brushes past brushes 63 causing an electrical signal to be detected by suitable apparatus (not shown). This signal can be used to place the beam generation equipment in a ready condition.

As the shutter mechanism continues to rotate around post 45 the trigger 62 begins to engage the tilted gimbal 52. This trigger being fixed causes the gimbal to exert an upwards force against spring 59. At a selected point, fixed by the angle of the gimbal to the top 44 and the length of trigger 62 beneath top 44, the gimbal begins to pivot around points 53 and 54. As rotation continues this interaction between the gimbal and trigger causes the gimbal to reach a position parallel to top '44. When this Position is reached the lip 55 is raised above shaft 56 releasing the shutter mechanism. Ideally this position (when the gimbal 52 is parallel to top 44) should be reached just before the shutter 50 reaches the back of passageway 40 thus allowing the shutter 50 maximum acceleration distance.

During rotation of the shutter mechanism a spring 38 located on post 45 was being wound and now the action of this spring 38 caused the freed shutter mechanism to reverse and begin to travel in a clockwise direction towards seat 39. As it again passes brush 63 a signal is again initiated. This signal is now used to cause an intense pulse of electrical energy to pass along passageway 40. The length of this pulse is of course determined by the beam generation apparatus but generally is less than 1 nanosecond in length. During the time the beam is passing through passageway 40 the shutter is continuing towards seat 39 and finally seats itself there within less than 10 milliseconds after the pulse was generated by shaft 50 contacting brush 63. Actual tests show that this device closes within 7 milliseconds after initiation of the beam. Further tests indicate that modifications such as a change in the spring strength, and the addition of floating bearings in top 44 for device coupling 51 will appreciably increase this speed and bring the closing time of the shutter to within 1 millisecond.

Having now described different ambodiments of the present invention it is desired that the invention be limited and defined only by the appended claims.

What is claimed is:

1. A valve for closing a passageway in less than 10 milliseconds comprising a base plate having an aperture therein, a tube on said plate and around said aperture, the longitudinal axis of said tube being perpendicular to said plate and defining a passageway, a seat on said tube and spaced from said plate by said tube, a post on said plate parallel to said tube, a gate on said post and rotatable around the axis of said post, said gate being positioned to mate with said seat and seal said passageway when in a closed position, spring means coupled to said gate to urge said gate in mating contact with said seat, means for driving said gate along an arcuate path around the axis of said post in opposition to said spring means to open said passageway and to increase the tension in said spring and means for releasing said gate from said driving means at a predetermined point in the arcuate path described by said gate to permit said spring to urge said gate along the arcuate path and to rest on said seat.

2. The valve of claim 1 wherein said seat is positioned at an angle with respect to the longitudinal axis of said 5 tube and said gate is maintained on said post at a substantially identical angle.

3'. The valve of claim 1 wherein said seat is surrounded by a compressible annulus.

4. The valve of claim 1 wherein said driving means comprises a device coupling rotatably mounted on said post, a gimbal pivotably supported on said coupling, a lip on said gimbal for engaging said gate, spring means between said gimbal and said coupling for urging said lip into engagement with said gate and a motor coupled to said drive coupling.

5. The valve of claim 1 wherein said gate is provided 6 with means to permit said gate three degrees of freedom to permit self adjustment of said gate on said seat.

References Cited UNITED STATES PATENTS 1,238,944 9/1917 Rogers et a1. 251301 XR.

2,716,455 1/1953 Jones 251r'303 XR 2,907,502 10/ 1959 Lang 251300 XR FOREIGN PATENTS 1,264,880 5/1961 France.

RONALD FELDBAUM, Primary Examiner

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