Title:
VALVE GUIDES FOR METER SLIDE VALVES
United States Patent 3693444


Abstract:
A self-stabilizing valve guide secured in a slot in a meter valve housing to guide a slider rod of a slide valve. The valve guide is snapped into position within the slot wherein pairs of tabs formed on said guide hold the same in position. A lock tab is formed on said guide to permit limited yielding of said guide due to external forces, but prevents the pairs of tabs from being unseated from the slot.



Inventors:
CARROLL KENNETH A
Application Number:
05/166882
Publication Date:
09/26/1972
Filing Date:
07/28/1971
Assignee:
SINGER CO.:THE
Primary Class:
International Classes:
G01F3/22; (IPC1-7): G01F11/08
Field of Search:
73/268 308
View Patent Images:
US Patent References:
2818046Gas meters1957-12-31Evans



Foreign References:
CH303702A1954-12-15
Primary Examiner:
Gill, James J.
Claims:
Having thus set forth the nature of the invention, what I claim herein is

1. A self-stabilizing valve guide adapted to be secured in a slot in a valve housing to guide a slider rod of a slide valve, said valve guide comprising:

2. The combination claimed in claim 1 wherein:

3. The combination claimed in claim 1 wherein:

4. A shock absorbing valve guide adapted to be secured in a slot in a valve seat for guiding a slider rod of a gas meter slide valve, said valve guide comprising:

5. The combination claimed in claim 4 wherein:

6. The combination claimed in claim 4 wherein:

7. The combination claimed in claim 6 wherein:

Description:
BACKGROUND OF THE INVENTION

Heretofore, valve guides have included a two piece assembly consisting of a rigid valve guide and a screw by which the guide was screwed into the valve seat. This required two parts for the guide and drilling and tapping of the valve seat. Such a rigid construction of the valve guide resulted in breakage of the valve guide when the same was subjected to external forces. One piece rigid mounting members were also known, but such members lacked flexibility, and therefore, were also subject to damage due to external forces.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide an improved valve guide which overcomes the prior art disadvantages; which is simple, economical and reliable; which is a one piece valve guide; which is self-stabilizing; which permits a limited movement of the inserted valve guide without permitting the same to be unseated when the valve guide is subjected to external forces; which uses a lock tab which permits limited valve guide shifting, but not removal; and which provides for positive locking of the lock tab.

Other objects and advantages will be apparent from the following description of several embodiments of the invention and the novel features will be particularly pointed out hereinafter in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

This invention is illustrated in the accompanying drawings in which:

FIG. 1 is a top plan view, partly broken away, of a meter having a valve assembly embodying the preferred form of the present invention;

FIG. 2 is an enlarged perspective view, partly broken away, of the valve assembly, showing the improved valve guide in assembled position therein;

FIG. 3 is a front elevational view of the improved valve guide mounted in the valve assembly in normal operative position;

FIG. 4 is a front elevational view of the improved valve guide in collapsed position and inserted half-way into a slot of the valve seat;

FIG. 5 is a front elevational view of the improved valve guide being subjected to an external force which causes it to pivot about point A;

FIG. 6 is a front elevational view of the improved valve guide wherein the lock tab has restored stability at point A and prevented unseating of the valve guide from within the slot of the valve seat;

FIG. 7 is a top plan view of a slot into which the improved valve guide of the present invention is mounted;

FIG. 8 is a view taken along line 8--8 of FIG. 3;

FIG. 9 is a modified embodiment of the improved valve guide showing a fragmentary view thereof;

FIG. 10 is another modified embodiment of the improved valve guide showing a fragmentary view thereof.

DESCRIPTION OF THE INVENTION

The preferred embodiment of the invention illustrated in FIGS. 1-8, wherein a conventional meter such as a gas meter 10 is shown in FIGS. 1 and 2 having a housing 12 into which gas is introduced through an inlet 14 for delivery to a valve chamber 16. A valve assembly 18 is mounted on a meter table 20 and controls the flow of gas from the valve chamber 16 into and out of gas measuring chambers (not shown), from which the gas is discharged through outlet 22. A pair of flag rods 24 only one of which is shown in FIGS. 1 and 2, is journaled in the meter table 20 and operatively connected within the gas measuring chamber to be reciprocated thereby. A flag arm 26 is pivotally connected as at 28 by a pivot link 30 to a crank arm 32 and a valve arm 34. The crank arm 32 is connected at its opposite end to a crank (not shown) which is continuously driven by one or the other of the flag rods 24. The valve arm 34 is pivotally connected as at 36 by a pin 38 affixed to a slide valve 40 of the valve assembly 18. The valve arm 34 will reciprocate the slide valve 40 to alternately connect the inlet 14 and the outlet 22 with the gas measuring chamber in a predetermined sequence to measure the throughput flow of the meter 10.

The valve assembly 18 also includes a valve seat or housing 42, slider rods 44 and the improved valve guide 46.

The valve housing 42 as shown in FIGS. 1 and 2, is secured to the meter table 20 by a plurality of screws 48. Parallel seating ribs 50 project upwardly from the surface of the housing 42 and serves as slides upon which the valve 40 reciprocates. Inwardly of the ribs 50 are aligned openings (not shown) through the housing 42 and table 20 which the valve 40 covers or interconnects in the course of its operation.

The slider rods 44 are connected into raised projections 52 formed on opposite sides of the slide valve 40. The slider rods 44 extend in opposite directions along the reciprocal path of the slide valve 40. The free end of each of the slider rod 44 passes through and is held captive within the valve guide 46 so as to prevent the valve 40 from being displaced from the slide track provided by the ribs upon which valve 40 reciprocally slides.

The valve guide 46 is mounted within a slot 54, illustrated in FIGS. 2, 3 and 8.

The slot 54 is shown in FIG. 7 in top plan view prior to the valve guide 46 being mounted therein. The slot 54 is rectangularly shaped and extends through the valve housing 42 from the top surface 56 to the bottom surface 58 thereof. The long side 60 of the slots 54 extend in a direction perpendicular to the ribs 50, while the short side 62 of the slot 54 extend in a direction parallel to the ribs 50. The vertical wall 64 of the long side 60 extend the full thickness of the valve housing 42 from the top surface 56 to the bottom surface 58 thereof. The vertical wall 66 of the short side 62 communicates at the top thereof with a top recess 68 formed inwardly of the top surface 56 along the length of each of the short sides 62, and at the bottom thereof with a bottom recess 70 formed inwardly of the bottom surface 58 along the length of each of the short sides. The vertical wall 66 is of shorter height than that of wall 64 by an amount equal to the combined depth of the recesses 68 and 70. The top recess 68 is formed in superposition to the bottom recess 70. The top recess 68 is substantially thinner and slightly wider than the deeper shorter bottom recess 70. The vertical wall 66 of the short side 62 at its upper end terminates in an upper shoulder 72 which forms the upper surface of the top recess 68, and at its lower end terminates in a lower shoulder 74 which forms the undersurface of the bottom recess 70.

The valve guide 46, illustrated in FIGS. 2, 3, 4 and 8, includes a substantially inverted U-shaped one-piece body member 76, having an arcuate top section 78 and parallel legs 80 and 82, extending therefrom. An end tab 84 is formed at the bottom of each of the legs 80 and 82 to extend outwardly therefrom in a direction away from each other. An intermediate tab 86 is formed on each of the legs 80 and 82 to extend outwardly therefrom in a direction away from each other. The pairs of tabs 84 and 86 are formed substantially perpendicular to the longitudinal axis of the respective legs 80 and 82. The distance measured from the undersurface of the intermediate tab 86 to the upper surface of the end tabs 84 is predetermined to equal the height of the vertical wall 66. The intermediate tabs 86 are inclined slightly downwardly, to provide a built-in tolerance and are deflectable so as to place the valve guide 46 in tension upon being mounted in assembled position as shown in FIG. 3, within the slot 54. The slight incline of the intermediate tab 86 creates a clearance space 88, seen best in FIG. 3, between the upper surface of the top recess 68 and the undersurface of the intermediate tab 86.

A lock tab 90 is formed on the interior side of the leg 80, adjacent the bottom thereof to extend in a substantially horizontal plane perpendicular to the longitudinal axis of the leg 80. The lock tab extends toward the leg 82 and terminates a predetermined distance, designated generally as X, from the leg 82 as illustrated in FIG. 3. The X distance represents the distance which either one or both of the respective legs 80 and 82 is free to move toward each other before the lock tab 90 contacts the interior side of the leg 82 for purposes more fully explained hereinafter.

In normal position, the valve guide 46 has its legs 80 and 82 disposed parallel to each other so that the width of the guide measured from tip to tip of the end tabs 84 is substantially greater than the distance of the long side 60 measured from one wall 66 of the short side 62 to the other thereof. Actually, in the assembled position shown in FIG. 3, the valve guide 46 has a distance from tip to tip of the end tab 84 which corresponds to the distance measured between the outer edges of the adjacent bottom recesses 70. The valve guide 46 has an inherent resiliency and though the body member is dimensionally stable, it is readily bendable about the top section 78. This serves the dual function of permitting a snap-in assembly of the valve guide 46, and enables the valve guide 46 to withstand shock and extraordinary forces which it may be subjected to while in assembled position.

The valve guide 46 is inserted into the slot 54 vertically downwardly as shown in FIG. 4. However, in the preferred embodiment in order to insert the valve guide 46 into the slot 54, the legs 80 and 82 must be collapsed toward each other as illustrated in FIG. 4. This may be conveniently done by slipping a shim under the bottom of the leg 82 and over the top of the free end of the lock tab 90. Forcing the legs 80 and 82 toward each other will cause the leg 82 to ride over and seat upon the top of the lock tab 90, after which the shim is removed while the legs 80 and 82 are held in collapsed position. The vertical sides of the end tab 84 are sloped upwardly and outwardly from the bottom of each of the end tabs 84 so as to provide the narrowest dimension at the bottom thereof, as a further aid in assembling the valve guide 46 in the slot 54. In the collapsed position, the valve guide 46 as illustrated in FIG. 4, has a slightly smaller width measured from tip to tip of the end tabs 84 than the length of the long side 60 measured from the distance between opposite vertical walls 66 of the short side 62. Accordingly, the valve guide 46 is vertically inserted into the slot 54 until the underside of the intermediate tabs 86 contacts the upper surface of the top recess 68 and then the legs 80 and 82 are released from their collapsed position to snap into position within the bottom recess 70 to complete the assembly of the valve guide 46.

The valve guide 46 is shown in assembled position in FIGS. 2 and 3. Each of the end tabs 84 is disposed within the lower recess 70 and is snugly engaged with the lower shoulder 74. Each of the intermediate tabs 86 engages the upper shoulder 72 and is deflected by such engagement an amount sufficient to place the portion of the legs 80 and 82 between the superimposed pairs of tabs 84 and 86 in tension, thus offering positive resistance to any vertical movement of the valve guide 46.

Upon the occurrence of a horizontal force represented in FIGS. 5 and 6 by the arrow 92 shown within the valve rod 44 caused by shock or other extraordinary forces, the rod 44 will contact the interior of the leg 82. As the force represented by the arrow 92 is applied, the leg 82 tends to rotate away from the wall 66 as shown in FIG. 5 about a pivot point, designated generally A, formed on the valve housing 42 at the intersection of the vertical wall 66 and the upper shoulder 72. Simultaneously, the valve guide 46 begins to collapse. The rotation and collapse of the respective leg 82 and guide 46 continues until the movement of the leg 82 brings it into contact with the free outer end of the lock tab 90. Thereafter, the inherent rigidity of the valve guide 46 will cause the leg 80 to move toward the leg 82 so that the lock tab 90 pushes the leg 82 forcing it to pivot about point A toward the wall 66, as illustrated in FIG. 6. In other words, the horizontal force produces a rocking action in the legs 80 and 82 due to the interaction of the lock tab 90. This rocking action would be the same, but in the opposite direction, if the horizontal force were applied leftwardly instead of as is shown in FIGS. 5 and 6 as being applied rightwardly. Once the lock tab 90 has been brought into contact with the leg 82 whether the horizontal force is being applied from the right side as shown or the left side, the force will be converted from rotational motion and collapse of the valve guide 46 to compression of the lock tab 90. The valve guide 46 is self-stabilizing and permitted only partial collapse due to the action of the lock tab 90. Though the legs 80 and 82 have limited motion in the horizontal direction, such movement is substantially equal to the X distance depicted in FIG. 3, for upon the locking tab 90 contacting the leg 82 the valve guide 46 becomes rigid, and further closure of the legs 80 and 82 is prevented. However, some flexibility of the valve guide 46 is retained due to the length of the legs 80 and 82, which is helpful in dissipating a shock load. In any event, the end tabs 84 contact the shoulder 74 to prevent the valve guide 46 from being vertically lifted out of the slot 54, while the intermediate tabs 86 contact the shoulders 72 to prevent the valve guide 46 from dropping vertically into the slot 54.

The result of the lock tab 90 contacting the leg 82 is that even under shock or other extraordinary force the valve guide 46 remains securely mounted within the slot 54. Additionally, whenever a force is applied to either of the legs 80 or 82, the inherent flexibility of said legs will aid in dissipating such force, without causing the valve guide 46 to break unless the load limits of the material from which the guide is made are exceeded.

In the modified form of the invention, the improved valve guide is depicted in FIGS. 9 and 10 by the reference character 46a and 46b respectively. Referring to FIGS. 9 and 10, the reference characters will be identical with that of the preferred embodiment, except as specifically identified hereinafter by lower case letters.

Accordingly, the modified form of the invention illustrated in FIG. 9, provides a positive locking engagement of the lock tab 90a and the leg 82a. The lock tab 90a has an arcuate tip 94a which is normally out of contact with a semicircular groove 96a formed in the bottom of the leg 82a on the interior side thereof opposite the lock tab 90a. Upon the valve guide 46a being subjected to a horizontal force as was described hereinbefore, a partial collapse of the guide valve 46a will cause the leg 82a to pivot into contact with the lock tab 90a wherein the tip 94a will be disposed within the groove 96a to prevent any vertical shifting of either leg 80a or 82a with respect to the other.

The modified form of the invention illustrated in FIG. 10 provides a positive locking engagement similar to that described under FIG. 9 except that the lock tab 90b of the valve guide 46b has a V-shaped tip 94b which is normally out of contact with a correspondingly shaped V groove 96b formed on the interior side of the leg 82b adjacent the bottom thereof. The V-shaped tip 94b will mate with the V-shaped groove 96b in positive locking engagement therein when the leg 82b pivots upon the valve guide 46b partially collapsing as a result of a horizontal force being exerted thereon as was described hereinafter.

It will be understood that various changes in the details, materials, arrangements of parts and operating conditions which have been herein described and illustrated in order to explain the nature of the invention may be made by those skilled in the art within the principles and scope of the invention.