Position indicator for a rotary valve actuator

A position indicator for and method for applying the same to valve arrangements having a first strip attached to a first movable part and a second strip attached to a second stationary part of the valve arrangement. The strips have a line arranged down the middle with contrasting lines on either side for easy alignment of the indicator strips. The indicator strips are initially applied as a single strip to the first and second parts of the valve arrangement and then severed at a point between the first and second parts when the valve arrangement is in a known preferred position.

BACKGROUND AND SUMMARY OF THE INVENTION 
The present invention relates generally to a position indicator for rotary 
valve actuators, and more specifically to a position indicator which 
indicates when the valve is in a desired position. 
It is often desirable to know the position of the closure mechanism within 
a valve body for determining the flow of a medium passing through the 
valve. This is of particular importance in systems requiring frequent and 
accurate adjustment of the valve's medium flow. Additionally, because 
valve actuators are often located in areas which are poorly lighted, it is 
desirable to have an indicator means which can be easily read in dark 
environments. 
Various methods have been previously devised to provide some means of 
indicating the position of the valve. U.S. Pat. No. 2,959,149 to Schwenk 
describes an underground rotary valve having an indicating disc positioned 
on and arcuatly movable with the valve shaft. When one of two markings on 
the disk are aligned with one mark positioned on the housing itself, the 
position of the valve closure member may be known. Another valve described 
in U.S. Pat. No. 2,767,681 to Pontius includes an indicator pointer which 
is keyed to rotate with the valve stem by a differential gear. A 
corresponding indicator plate journalled on the valve stem is calibrated 
for indicating the open and closed positions of the valve. Another valve 
position indicator described in U.S. Pat. No. 2,140,934 to Dopp is formed 
by a vertical cut made into the side of the valve stem. The vertical 
position of this cut corresponds to a right angle of the flow direction 
within the valve body to indicate when the valve is in a closed position. 
Because the above position indicators require additional parts such as 
discs or further manufacturing such as making cuts on the valve stem or 
body, these indicators are both time consuming and costly to implement. 
Additionally, these indicators are not easily implemented on valves 
already in use or easily readable in poorly lighted environments. 
It is, therefore, an object of the present invention to provide an 
inexpensive and accurate means for indicating the position of the closure 
mechanism within a valve arrangement. 
Another object of the present invention is to provide an inexpensive and 
accurate position indicator which may be easily implemented on valves 
already in use. 
Still another object of the present invention is to provide an inexpensive 
and accurate position indicator which is easily readable under all types 
of lighting conditions. 
It is still another object of the present invention to provide an 
inexpensive and accurate position indicator which is easily replaceable 
upon being worn. 
These and other objects are attained by providing a position indicator 
means having a first position indicator strip arranged on a valve actuator 
stem or shaft and a second position indicator strip arranged on a 
stationary portion of a valve body such as a bonnet pad, compression plate 
or actuator body. The strips are positioned such that when they are in 
alignment with each other, the position of the closure mechanism within 
the valve is in a fully closed or fully opened position or any 
intermediate position for which an accurate indication is desired. 
The indicator strips initially comprise a single strip which is applied to 
both the rotor valve actuator shaft and a stationary surface when the 
closure mechanism is in a preferred position. After the strip is attached 
to the respective parts of the valve, it is severed at a point where the 
actuator and stationary surface meet, thereby providing accurate alignment 
of the two strips when the valve is in the preferred position. Depending 
upon the valve structure, the strips can be attached to either a top or 
side part of the valve actuator shaft for providing respective top or side 
views of the same. 
The strips can be formed from a plastic, aluminum or other inexpensive 
material having an adhesive on one face of the strips for attaching the 
same to the respective parts of the valve. The other face of the strips 
include a longitudinal area down the middle which is bordered by 
contrasting areas on either side. Use of fluorescent materials for these 
areas may be used to further improve readability of the indicators in 
poorly lighted environments. 
Because the strips are applied to the respective valve parts with an 
adhesive, they can be easily replaced by a new strip when the old strips 
become worn.

DETAILED DESCRIPTION OF THE DRAWINGS 
Referring to FIGS. 1 and 2, a preferred embodiment shows a shaft 11 and 
body 12 forming the top portion of a valve arrangement 10. An O-ring seal 
20 is provided between the shaft 11 and the body 12. The valve shaft 11 
includes a handle 13 at one end and a closure mechanism (not shown) at the 
other end. The type of closure mechanism will depend on the type of valve 
arrangement, such as a rotary actuator for a butterfly or ball valve. A 
bonnet pad 14 is formed on the valve body having a planar surface 
transversed to the shaft 11. 
A position indicator means 15 comprises at least two strips, 16, 17, having 
distinctive contrasting areas 18, 19 on a first face for easy alignment 
and readability. An adhesive material on a second face of the strips 16, 
17 is used for attaching the same to the vertical surface of the valve 
shaft 11 and the planar surface of the bonnet pad 14 respectively. The 
indicator strips 16, 17 are arranged on the respective parts 11, 14 such 
that the valve mechanism (not shown) is in a closed position when the two 
position indicator strips 16 and 17 are aligned with each other. The 
position indicator strips, however, may also be arranged such that they 
are aligned when the closure mechanism is in other known preferred 
position. 
The indicator strip may also be applied to the valve actuator and the valve 
actuator housing as illustrated in FIG. 3. The actuator shaft 11 is shown 
extending from the valve housing 12 and is sealed thereto by an O-ring 20. 
An actuated drive member 22 is secured to the actuator shaft 11 by a key 
24. Actuating housing walls 26 and 28 encompass the actuator drive member 
22 and the shaft 11. The position indicator means 15 is shown having one 
strip 16 on the stationary actuator housing 26 and a second strip 17 on 
the top of the actuator drive member 22. The actuator strips 16 and 17 are 
in a common plane and may be viewed from the top. 
The indicator means 15 having two portions 16 and 17 at right angles to 
each other may also be applied to a valve having compression plates as 
illustrated in FIG. 4. The valve body 12 is shown as receiving the 
actuator shaft 11 with the plurality of seals 30. A compression plate 32 
is secured to the body 12 by fasteners 34 and compressed the stacked seals 
30. As in FIG. 1, the indicator means 15 includes an indicator strip 16 on 
the rotary actuator shaft 11 and a portion 17 on the stationary portion 
which in this case is the compression plate 32. 
In the preferred embodiments, the position indicator strips are formed from 
a single strip 15, which is applied to both the rotary member and the 
stationary member by the adhesive backing. When the closure mechanism is 
in a desired position, the single strip 15 is cut at a point between the 
respective parts, thereby providing an accurate alignment between the two 
strips 16, 17 for indicating the desired position of a valve. This 
operation can be performed during or after assembly of the valve 
arrangement at minimal cost and time. 
From the preceding description of the preferred embodiments, it is evident 
that the objects of the invention are attained, and although the invention 
has been described and illustrated in detail, it is to be clearly 
understood that the same is by way of illustration and example only and is 
not to be taken by way of limitation. The spirit and scope of the 
invention are to be limited only by the terms of the appended claims.