Pipeline valve transmission apparatus

An apparatus is provided which includes a valve transmission designed to connect a valve actuator to a rotational valve. The valve transmission includes a pinion, a pair of stepped racks, and a lower gear, all within a housing. The pinion is designed to be driven by a rotating shaft of an actuator. The pinion engages the teeth of the racks on the upper steps. The lower steps of the rack are displaced laterally from the upper steps to engage a lower gear that is either of lesser or greater diameter than the pinion depending on whether a positive or negative mechanical advantage is desired. The lower steps drive the lower gear which is connected to the drive shaft of a rotational valve. The transmission is placed within a housing which removeably mounts to the valve body.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to pipeline valve apparatus and, more 
particularly, to improvements in valve transmission apparatus. 
2. Description of the Invention Background 
Various methods and devices for imparting rotary motion to rotary actuated 
devices are known in industry. For example, ball and butterfly valves that 
are used for controlling the flow of liquid materials ranging from milk to 
oil are commonly controlled by rotary actuators that convert linear motion 
to rotary motion. In addition, rotary actuators have also been used to 
impart rotary motion to indexing tables on small part assembly lines in 
the electronics industry. In general, rotary actuators have also been used 
in a plethora of other process and assembly operations requiring rotary 
motion. Such rotary actuators, in some applications, are directly linked 
to the valves or other devices to be rotated. However, it is desirable to 
have a transmission between the actuator and the valve which alters the 
speed of rotation and torque between the output shaft of an actuator and 
input shaft to the valve or other devices. In some applications, the 
device to be rotated requires greater power than the actuator is capable 
of producing. In other applications, it is necessary to increase or 
decrease the speed of rotation of the valve from the speed of rotation of 
the actuator shaft. Transmissions are desirable which will achieve the 
increased or decreased torque or speed while transmitting the motion from 
the actuator to the valve. 
Heretofore, valve transmissions have been of various types including, for 
example, a transmission which has an actuator and transmission integral 
with one another. This transmission has a piston, which when actuated, 
drives a rack in lateral alignment with the piston to turn a pinion. Such 
an arrangement severely limits the versatility of the transmission as the 
actuator and transmission are one unit. Also, in order to change the gear 
ratio or other operating characteristics of such a transmission, the 
entire actuator/transmission unit must be replaced. A transmission is 
needed which provides for a simple method of changing the gear ratio 
without replacing the entire actuator. 
A transmission is also needed which includes electronic and mechanical 
monitoring systems to indicate the position of the valve. 
A transmission is further needed which will permit accurate, efficient and 
effective conversion of the linear motion of an actuator to rotary motion 
for an object to be rotated. 
The present invention is directed toward an improved design for a valve 
transmission apparatus which overcomes, among others, the above discussed 
problems. 
BRIEF SUMMARY OF THE INVENTION 
The present invention provides a valve transmission which overcomes many of 
the deficiencies of valve transmissions in the past. The valve 
transmission is designed to connect a valve actuator, such as the one 
found in my U.S. Pat. No. 5,170,693, the disclosure of which is hereby 
incorporated by reference, to a rotational valve, such as the one found in 
my U.S. Pat. No. 5,160,118, the disclosure of which is also hereby 
incorporated by reference. 
The valve transmission of the present invention is versatile in that it can 
be manufactured in a wide range of gear ratios by providing a variety of 
gear sizes to suit particular needs. The gear ratio will, of course, 
determine the ratio of input to output speed and the ratio of input to 
output torque. 
The valve transmission includes a pinion, a pair of stepped racks, and a 
lower gear, all within a housing. The pinion is designed to be driven by a 
rotating shaft of an actuator. Each stepped rack has an upper step and a 
lower step which are connected together by a mounting block. The upper 
step and the lower step have teeth on parallel planes. The pinion engages 
the teeth of the rack on the upper step. Under most operating conditions, 
it is desirable to have the lower step of the rack on a separate but 
parallel plane from the upper step to engage a lower gear that is either 
of lesser or greater diameter than the pinion depending on whether a 
positive or negative mechanical advantage is desired. However, one skilled 
in the art will recognize that the upper and lower racks may be aligned to 
provide a pinion and lower gear of equal diameters. The optimum gear ratio 
for any given application is determined by many variables as one skilled 
in the art will also recognize. The lower step drives the lower gear which 
is connected to the drive shaft of a rotational valve. The transmission is 
placed within a housing which removeably mounts to the valve body and 
actuator. 
As the rack is not integral to the actuator, the entire transmission may be 
replaced or component parts may be changed; thus, the transmission 
overcomes many of the deficiencies of the transmissions of the past. 
Additionally, as will become readily apparent, the transmission is 
versatile in that, through minor modification, the mechanical advantage 
provided by the gear ratio can be easily modified or even inverted. 
Further, the transmission apparatus disclosed herein allows for a desired 
position to be efficiently attained and maintained until repositioning is 
desired. 
These and other details, objects and advantages of the present invention 
will become apparent as the following description of the preferred 
embodiment thereof proceeds.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawings wherein the showings are for purposes of 
illustrating the preferred embodiments of the present invention only and 
not for purposes of limiting same, the Figures show a valve transmission 
apparatus 10 for use in connection with an actuator and a butterfly valve. 
FIG. 1 illustrates the present invention connected to an actuator 12 and a 
butterfly valve 14. The transmission housing 16 has a position indicator 
18 which together with pointer 19 indicates the location of the butterfly 
valve 14. The transmission housing 16 is preferably made of steel or 
aluminum, although it can be made of any one of many suitable materials. 
In FIG. 2, the valve transmission 10 is shown with a mounting flange 20 
having bores 22 and 24 for attachment to a flange in a pipeline (not 
shown). Referring to FIGS. 3 and 4, within the housing 16 is a pinion 30 
having teeth 32 and a coupling slot 34. The coupling slot 34 is adapted to 
receive rotational input from a corresponding actuator shaft (not shown) 
to which rotary motion has been imparted by known actuating means or by 
the actuator disclosed in my U.S. Pat. No. 5,170,693. A pair of stepped, 
opposed racks 40 and 41 are provided within housing 16. However, it will 
be appreciated that only one rack 40 or 41 may be used in the principle 
and scope of the present invention. Each stepped rack, as described more 
fully below, is constructed in the shape of, in side view, an "L" with the 
vertical surfaces of the "L" having teeth thereon. The racks are 
preferably made of steel or other materials known for use in commercial 
gear manufacture. The rack 40 has teeth 42 in the vertical plane 42a on 
upper step 44 which correspond to the teeth 32 on the pinion 30. 
Similarly, a rack 41 has teeth 43 in the vertical plane 43a on the upper 
step 45 which correspond to the teeth 32 on the pinion 30. The rack 40 has 
a lower step 46 with teeth 48 on the vertical plane 48a. Similarly, the 
rack 41 has a lower step 47 with teeth 49 on the vertical plane 49a. If 
desired, as best seen in FIGS. 9-12, each of the racks 40 and 41 may be 
comprised of different appropriate materials such as steel and brass and 
held together by bolts 36 and 38 on the rack 40 and bolts 37 and 39 on the 
rack 41. In such case, mounting blocks 57 and 59, of brass or other 
appropriate material, may be utilized to attach the upper steps 44 and 45, 
respectively, to the corresponding lower steps 46 and 47, respectively. In 
addition, the pointers 19 can be directly attached to the racks 40 and/or 
41. 
A lower gear 60, as best seen in FIGS. 3 and 4, has a bore 61 for receiving 
a shaft 63 and teeth 62 which correspond to the teeth 48 on the rack 40 
and teeth 49 on the rack 41. Although the Figures depict one ratio of 
upper step separation to lower step separation (i.e. the ratio of pinion 
diameter to lower gear diameter), one of ordinary skill in the art will 
recognize that a great variety of ratios are possible. The shaft 63 may 
include a slot 35 or other means for connection to a valve such as 
disclosed in my U.S. Pat. No. 5,160,118 or other apparatus to be rotated. 
As shown in FIGS. 9 and 10, the racks 40 and 41 have contact surfaces 50 
and 51, respectively. The racks 40 and 41 are disposed within the front 
and back housing plates 16 for translational movement on a mounting base 
70. The mounting base 70 can be made of any appropriate material which 
will support the racks 40 and 41 for sliding movement such as, for 
example, steel, brass, aluminum or a rigid polymer. The screws 79 secure 
the front and back housing plates 16 to the mounting base 70. As shown in 
FIGS. 7A and 7B, the mounting base 70 has a bore 68 for receiving the 
lower gear 60. Shim bearing surfaces 72 and 74 adjacent to the mounting 
base 70 are provided to permit translational movement of the racks 40 and 
41, respectively. Contact surfaces 50 and 51 bear upon the shim bearing 
surfaces 72 and 74, respectively, to allow for sliding contact between the 
racks 40 and 41, respectively, and the shim bearing surfaces 72 and 74, 
respectively, of the mounting base 70. The shim bearing surfaces 72 and 74 
can consist of brass or other materials with a low coefficient of friction 
upon which the racks 40 and 41 may translate. Guide surfaces 76 and 78, 
along with vertical guide surfaces 71 and 75, are provided to ensure a 
true, straight horizontal translation of the racks 40 and 41. Guide 
surfaces 76 and 78 contact rack guide surfaces 66 and 67, respectively. 
Vertical guide surfaces 71 and 75 contact bearing surfaces 73 and 77, 
respectively, to maintain horizontal translation of the racks 40 and 41. 
The housing 16 also has side bearing surfaces 52 and 53, respectively, to 
facilitate translation of the racks 40 and 41, respectively. Surface 56 on 
rack 40 and surface 55 on rack 41 slide across side bearing surfaces 52 
and 53, respectively. 
As shown in FIGS. 5 and 6, the positions of the pinion 30, the racks 40 and 
41 and the lower gear 60 may be arranged in reverse, which provides a 
90.degree. valve rotation with a significantly shorter actuator travel 
stroke, and increased speed. This gear arrangement is more conducive to 
hydraulic application, whereas the embodiment shown in FIGS. 3 and 4 
provides mechanical advantage but sacrifices piston volume displacement 
performance, which is better suited for pneumatic actuation. In FIG. 6, 
the positions of the pinion 30 and the lower gear 60 have been reversed 
from those shown in FIG. 4. Also, the mounting base 70 is replaced with 
the mounting base 170, consisting of the same material. The front and back 
mounting plates 16 are connected to the mounting base 170 by screws 179, 
shown in FIGS. 8A and 8B. FIGS. 9 and 10 show a side view of the racks 40 
and 41 in the first position (i.e. corresponding to FIGS. 3 and 4) and 
FIGS. 11 and 12 show the racks 40 and 41 in the inverted position (i.e. 
corresponding to FIGS. 5 and 6). Also shown in FIGS. 9, 10, 11 and 12 are 
the pointers 19 (FIGS. 9 and 10) and 119 (FIGS. 11 and 12) which project 
through the housing 16 to illustrate the position of the valve. 
Mounting base 170 has shim bearing surfaces 172 and 174, similar in 
composition to shim bearing surfaces 72 and 74. In the inverted position, 
the contact surface 150 of the rack 40 bears on the shim bearing surface 
172 and the contact surface 151 of the rack 41 bears on the shim bearing 
surface 174. The mounting base 170 also includes a bushing 168 to support 
and stabilize the pinion 30 and a guide post 171 to facilitate horizontal 
translation of the racks 40 and 41. 
If desired, stop members 80 and 82 can be inserted in bores 84 and 86 or 88 
and 90 (FIG. 5) to limit the motion of the racks. Referring to the 
embodiment disclosed in FIGS. 5 and 6, the racks 40 and 41 travel a 
distance to produce a 90.degree. rotation which distance is much less than 
that of the racks shown in FIGS. 3 and 4. Therefore, travel stop 
extensions 180 and 182 are required. Additionally, electronic sensors 92 
and 94 (FIG. 2) may be provided to indicate full open and full closed 
positions of the valve. The sensors 92 and 94 may be connected to 
indicator lights 96 and 98 through appropriate circuitry, which is well 
within the skill of one skilled in the art to construct. 
In operation, referring to FIGS. 3 and 4, the output shaft of the actuator 
(not shown) is connected to the pinion 30 by slot 34. When the actuator 
rotates the actuator shaft, the motion is imparted to the pinion 30 which 
causes the pinion 30 to rotate. In turn, the rotation of the pinion 30, 
which has teeth 32 in engagement with the teeth 42 of rack 40 and teeth 43 
of rack 41, causes the pair of racks 40 and 41 to translate in opposite 
directions. The translation of the racks 40 and 41 causes the lower gear 
60, which has teeth 62 in engagement with teeth 48 of rack 40 and teeth 49 
of rack 41, to rotate. The lower gear 60, which when connected to an input 
shaft of the valve (not shown) by coupling slot 35 in shaft 63, drives the 
input shaft of the valve causing it to turn. The racks 40 and 41 can be 
moved by the actuator shaft and held in any desired position along the 
path of travel of the racks 40 and 41 so that the valve may be held in any 
position between and including the fully open and fully closed positions. 
The position of the valve 14 will be indicated by the position of pointer 
19 on position indicator 18. Also, the sensors 92 and 94 can indicate the 
valve position. 
It will be understood that various changes in the details, materials and 
arrangements of parts 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 principle and scope of the invention as expressed in 
the appended claims.