CA1315118C - Compact pressure gauge - Google Patents
Compact pressure gaugeInfo
- Publication number
- CA1315118C CA1315118C CA000560518A CA560518A CA1315118C CA 1315118 C CA1315118 C CA 1315118C CA 000560518 A CA000560518 A CA 000560518A CA 560518 A CA560518 A CA 560518A CA 1315118 C CA1315118 C CA 1315118C
- Authority
- CA
- Canada
- Prior art keywords
- cylinder
- rotating shaft
- pressure gauge
- piston
- secured
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Measuring Fluid Pressure (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A compact pressure gauge includes a cylinder which has a compressed gas inlet, a piston, a U-shaped piston rod, and a compression spring. The compression spring is sleeved on the piston rod in the cylinder for biasing the piston against the compressed gas pressure exerted on the piston. The U-shaped piston rod has parallel first and second arms. The first arm extends into the cylinder. The second arm includes a rack secured thereto. A rotating shaft includes an indicator secured thereto for displaying the rotational degree of the rotating shaft, and a pinion secured to the rotating shaft for meshing with the rack.
channel member is secured to the cylinder and has a guide slot through which the second arm extends. A
positioning plate is secured to the channel member so that the rotating shaft is journalled on the cylinder and the positioning plate. When the piston rod is moved, the rotating shaft is rotated due to the fact that the pinion always meshs with the rack.
A compact pressure gauge includes a cylinder which has a compressed gas inlet, a piston, a U-shaped piston rod, and a compression spring. The compression spring is sleeved on the piston rod in the cylinder for biasing the piston against the compressed gas pressure exerted on the piston. The U-shaped piston rod has parallel first and second arms. The first arm extends into the cylinder. The second arm includes a rack secured thereto. A rotating shaft includes an indicator secured thereto for displaying the rotational degree of the rotating shaft, and a pinion secured to the rotating shaft for meshing with the rack.
channel member is secured to the cylinder and has a guide slot through which the second arm extends. A
positioning plate is secured to the channel member so that the rotating shaft is journalled on the cylinder and the positioning plate. When the piston rod is moved, the rotating shaft is rotated due to the fact that the pinion always meshs with the rack.
Description
COMPACT PRESSURE GAUGE
BACKGROUND OF THE INVENTION
This invention relates to a pressure gauge, and more particularly to a compact pressure gauge.
A conventional pressure gauge generally has a structure similar to that illustrated as Prior Art and described below. The Prior Art constructions generally incorporate a toothed sector-like member, and the accuracy of the pressure gauge depends on the precision of the small teeth of the sector-like member, the fineness of which create difficulties in their manufacture. Furthermore, once dust deposits on the small teeth, undesired errors will be caused in measurement. Therefore, I disclosed an improved pressure gauge U.S. in Patent No . 4,715,222, which issued on December 29, 1987. In this improved pressure gauge, the sector-like member is replaced with a movable rack member. The rack member has an end portion movable in a cylinder, and the opposite end portion thereof is provid-ed with a toothed rack. Although it is easier to manu-facture the rack member than a sector-like member, the rack member occupies more space due to its linear arrangement and movement.
SUMMARY OF THE INVENTION
It is therefore the feature of this invention to provide a compact pressure gauge with a short rack member.
~k ' 131~118 According to this invention, a compact gauge includes a generally U-shaped rack member which has generally parallel first and second arms. The first arm extends into a cylinder and thus acts as a piston 5rod. The second arm has a rack.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of this invention will become apparent in the following detailed description of the preferred embodiments of this 10invention with reference to the accompanying drawings in which:
Fig. 1 is a sectional view of a conventional pressure gauge;
Fig. 2 is a sectional view of another 15conventional pressure gauge;
Fig. 3 is an exploded view of a compact pressure gauge in accordance with a first embodiment of this invention;
Figs. 4 and 5 are schematic views illustrating 20the operation of the compact pressure gauge in accordance with the first embodiment of this invention;
Fig. 6 is a sectional view showing the cylinder of the compact pressure gauge in accordance with a second embodiment of this invention; and 25Fig. 7 is an exploded view of a compact pressure gauge in accordance with a third embodiment of this invention.
-2A- 131~118 Referring to the Prior Art ~igure 1, which illustrates a conventional pressure gauge, the operation of the gauge results in angular displacement of the arcuate, toothed sector 10. My later developed gauge, shown in Figure 2, incorporates a toothed rack 20 which is displaced linearly along cylinder 30.
The Figure 1 prior art device is difficult to manufacture in view of the curved sector 10, with its small teeth. The teeth are susceptible to becoming dust laden, with diminution in accuracy.
The Figure 2 linear rack 20, owing to its.aligned relation and linearity of movement, requires greater space provision than the arcuate toothed section 10, of Figure 1.
. ~
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_ETAILED DESC~IPTION OF THE PREFERRED EMBODIMENTS
Referring to Figs. 3-6, a compact pressure gauge of this invention is shown. The compact pressure gauge includes an outer housing 1 which looks like a circular barrel. The outer housing 1 is formed in its upper surface with a circular hole 11. A cylinder body 2 is provided with two lugs 21, each of which has a threaded hole opposite a circular hole (not shown) in the outer housing 1, so that the cylinder body 2 is screwed to the outer housing 1 by two first lock bolts Bl. In addition, the cylinder body 1 has a cylindrical bore in its upper end surface and a square lower end opening formed in its bottom wall.
A channel member 22 of a U-shaped cross-section lS is integrally formed with the cylinder body 1 at a side wall thereof and has an open-ended guide slot. A U-shaped piston rod 3 has a first arm 31 of a square cross-section with an externally threaded upper end 311, and a second arm 32 of a rectangular cross-section including a rack 321 formed thereon. The first arm 31 extends into the bore in the cylinder body 1 through the square lower end opening of the cylinder body 2 so that a first compression spring 4 is sleeved on the first arm 31 in the cylinder body 1. The second arm 32 is received slidably in the guide slot in the channel member 22. An abutment element 5 has an internally threaded lower end 51 engaged threadably with the upper ,, ,,.. ", . ",.,,, . ,.,~,,, ,. ,.~ , .,,,, . , 1 ; , , end of the first arm 31 of the piston rod 3, and an outward flange 52 formed in its upper end surface with a screwdriver hole 521. With the screwdriver hole 521 provided in the upper end surface of the abutment element 5, the abutment element 5 can be screwed to the first arm 31 of the piston rod 3. After a seal 6 is placed into a cylinder cover 7, the lower end of th~
cylinder cover 7 is inserted tightly into the upper end of the cylinder body 1 so that the cylinder body 1 and the cylinder cover 7 form together a cylinder, as shown in Figs. 4 and 5. Consequently r the abutment element 5 is biased by the first spring 4 to abut against the seal 6 so that the seal 6 acts as a piston.
A pivot hole 23 is formed in a side wall of the cylinder body 1 so that a rotating shaft 8 is mounted rotatably on the cylinder hody 1 at an end thereof.
The opposite end of the rotating shaft 8 is inserted through a circular hole in a L-shaped positioning plate 9. The positioning plate 9 has two circular holes therein opposite two threaded holes (not shown) in the back of the channel member 22 so that the positioning plate 9 is screwed to the channel member 22 by two second lock bolts B2. After the rotating shaft 8 has been inserted through the positioning plate 9, it is also inserted through the central hole in a circular indicating plate P while permitting an indicating needle N to be secured thereto.
131~118 A pinion 81 is secured to the rotating shaft 8 for meshing with the rack 321 of the piston rod 3.
When the compact pressure gauge is idle, the seal 6 is pressed by the first spring 4 to abut against the upper wall of the cylinder cover 7, as shown in Fig. 5. When the compact pressure gauge is in use, compressed gas enters the cylinder cover 7 in a direction indicated by an arrow A to impel the seal 6, abutment element 5, and piston rod 3 downwardly. Because the pinion 81 always meshes with the rack 321, the downward movement of the piston rod 3 permits the rotating shaft 8 and the indicating needle N to be rotated.
As explained in the foregoing, the pressure gauge of this invention has a relatively small volume and a simple structure.
The bottom wall of the cylinder body 2 is provided on its inner surface with a stepped cylindrical spring seat 24. If necessary, referring to Fig. 6, an additional compression spring 4' may be located on the spring seat 24 around the first spring 4 to increase the spring pressure against the abutment element 5 and the seal 6.
Alternatively, referring to Fig. 7, the compressed gas inlet of the compact pressure gauge may be provided in the back of the outer housing, for convenience in reading. In this embodiment, the compact pressure gauge includes a cylinder body C with '. '.. -.. '.. ' ~'.'.. ' .
a cylindrical internal space (not shown) for receiving a piston, a piston rod, and at least one spring therein in the aforesaid manner. For clarity, the piston, piston rod, and spring are not shown in Fig. 7. The cylinder body C has a large threaded hole Cl formed in its upper surface and engaged sealingly with a large bolt B3, and a small threaded hole C2 formed in its inclined side surface and engaged sealingly with a small bolt B4. The inner end portion of the large threaded hole Cl is communicated with the inner end portion of the small threaded hole C2 through a straight gas passage Pl. The inner end portion of the small threaded hole C2 is communicated with the exterior of the outer housing H through a V-shaped gas passage P2. Certainly, O rings (not shown) may be sleeved on the large and small bolts B3 and B4 to ensure an air-tight seal between the cylinder body C
and the bolts B3 and B4.
~ith this invention thus explained, it is apparent that numerous modifications and variations can be made without departing from the scope and spirit of this invention. It is therefore intended that this invention be limited only as indicated in the appended claims.
.
BACKGROUND OF THE INVENTION
This invention relates to a pressure gauge, and more particularly to a compact pressure gauge.
A conventional pressure gauge generally has a structure similar to that illustrated as Prior Art and described below. The Prior Art constructions generally incorporate a toothed sector-like member, and the accuracy of the pressure gauge depends on the precision of the small teeth of the sector-like member, the fineness of which create difficulties in their manufacture. Furthermore, once dust deposits on the small teeth, undesired errors will be caused in measurement. Therefore, I disclosed an improved pressure gauge U.S. in Patent No . 4,715,222, which issued on December 29, 1987. In this improved pressure gauge, the sector-like member is replaced with a movable rack member. The rack member has an end portion movable in a cylinder, and the opposite end portion thereof is provid-ed with a toothed rack. Although it is easier to manu-facture the rack member than a sector-like member, the rack member occupies more space due to its linear arrangement and movement.
SUMMARY OF THE INVENTION
It is therefore the feature of this invention to provide a compact pressure gauge with a short rack member.
~k ' 131~118 According to this invention, a compact gauge includes a generally U-shaped rack member which has generally parallel first and second arms. The first arm extends into a cylinder and thus acts as a piston 5rod. The second arm has a rack.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of this invention will become apparent in the following detailed description of the preferred embodiments of this 10invention with reference to the accompanying drawings in which:
Fig. 1 is a sectional view of a conventional pressure gauge;
Fig. 2 is a sectional view of another 15conventional pressure gauge;
Fig. 3 is an exploded view of a compact pressure gauge in accordance with a first embodiment of this invention;
Figs. 4 and 5 are schematic views illustrating 20the operation of the compact pressure gauge in accordance with the first embodiment of this invention;
Fig. 6 is a sectional view showing the cylinder of the compact pressure gauge in accordance with a second embodiment of this invention; and 25Fig. 7 is an exploded view of a compact pressure gauge in accordance with a third embodiment of this invention.
-2A- 131~118 Referring to the Prior Art ~igure 1, which illustrates a conventional pressure gauge, the operation of the gauge results in angular displacement of the arcuate, toothed sector 10. My later developed gauge, shown in Figure 2, incorporates a toothed rack 20 which is displaced linearly along cylinder 30.
The Figure 1 prior art device is difficult to manufacture in view of the curved sector 10, with its small teeth. The teeth are susceptible to becoming dust laden, with diminution in accuracy.
The Figure 2 linear rack 20, owing to its.aligned relation and linearity of movement, requires greater space provision than the arcuate toothed section 10, of Figure 1.
. ~
, ;~
t~
_ETAILED DESC~IPTION OF THE PREFERRED EMBODIMENTS
Referring to Figs. 3-6, a compact pressure gauge of this invention is shown. The compact pressure gauge includes an outer housing 1 which looks like a circular barrel. The outer housing 1 is formed in its upper surface with a circular hole 11. A cylinder body 2 is provided with two lugs 21, each of which has a threaded hole opposite a circular hole (not shown) in the outer housing 1, so that the cylinder body 2 is screwed to the outer housing 1 by two first lock bolts Bl. In addition, the cylinder body 1 has a cylindrical bore in its upper end surface and a square lower end opening formed in its bottom wall.
A channel member 22 of a U-shaped cross-section lS is integrally formed with the cylinder body 1 at a side wall thereof and has an open-ended guide slot. A U-shaped piston rod 3 has a first arm 31 of a square cross-section with an externally threaded upper end 311, and a second arm 32 of a rectangular cross-section including a rack 321 formed thereon. The first arm 31 extends into the bore in the cylinder body 1 through the square lower end opening of the cylinder body 2 so that a first compression spring 4 is sleeved on the first arm 31 in the cylinder body 1. The second arm 32 is received slidably in the guide slot in the channel member 22. An abutment element 5 has an internally threaded lower end 51 engaged threadably with the upper ,, ,,.. ", . ",.,,, . ,.,~,,, ,. ,.~ , .,,,, . , 1 ; , , end of the first arm 31 of the piston rod 3, and an outward flange 52 formed in its upper end surface with a screwdriver hole 521. With the screwdriver hole 521 provided in the upper end surface of the abutment element 5, the abutment element 5 can be screwed to the first arm 31 of the piston rod 3. After a seal 6 is placed into a cylinder cover 7, the lower end of th~
cylinder cover 7 is inserted tightly into the upper end of the cylinder body 1 so that the cylinder body 1 and the cylinder cover 7 form together a cylinder, as shown in Figs. 4 and 5. Consequently r the abutment element 5 is biased by the first spring 4 to abut against the seal 6 so that the seal 6 acts as a piston.
A pivot hole 23 is formed in a side wall of the cylinder body 1 so that a rotating shaft 8 is mounted rotatably on the cylinder hody 1 at an end thereof.
The opposite end of the rotating shaft 8 is inserted through a circular hole in a L-shaped positioning plate 9. The positioning plate 9 has two circular holes therein opposite two threaded holes (not shown) in the back of the channel member 22 so that the positioning plate 9 is screwed to the channel member 22 by two second lock bolts B2. After the rotating shaft 8 has been inserted through the positioning plate 9, it is also inserted through the central hole in a circular indicating plate P while permitting an indicating needle N to be secured thereto.
131~118 A pinion 81 is secured to the rotating shaft 8 for meshing with the rack 321 of the piston rod 3.
When the compact pressure gauge is idle, the seal 6 is pressed by the first spring 4 to abut against the upper wall of the cylinder cover 7, as shown in Fig. 5. When the compact pressure gauge is in use, compressed gas enters the cylinder cover 7 in a direction indicated by an arrow A to impel the seal 6, abutment element 5, and piston rod 3 downwardly. Because the pinion 81 always meshes with the rack 321, the downward movement of the piston rod 3 permits the rotating shaft 8 and the indicating needle N to be rotated.
As explained in the foregoing, the pressure gauge of this invention has a relatively small volume and a simple structure.
The bottom wall of the cylinder body 2 is provided on its inner surface with a stepped cylindrical spring seat 24. If necessary, referring to Fig. 6, an additional compression spring 4' may be located on the spring seat 24 around the first spring 4 to increase the spring pressure against the abutment element 5 and the seal 6.
Alternatively, referring to Fig. 7, the compressed gas inlet of the compact pressure gauge may be provided in the back of the outer housing, for convenience in reading. In this embodiment, the compact pressure gauge includes a cylinder body C with '. '.. -.. '.. ' ~'.'.. ' .
a cylindrical internal space (not shown) for receiving a piston, a piston rod, and at least one spring therein in the aforesaid manner. For clarity, the piston, piston rod, and spring are not shown in Fig. 7. The cylinder body C has a large threaded hole Cl formed in its upper surface and engaged sealingly with a large bolt B3, and a small threaded hole C2 formed in its inclined side surface and engaged sealingly with a small bolt B4. The inner end portion of the large threaded hole Cl is communicated with the inner end portion of the small threaded hole C2 through a straight gas passage Pl. The inner end portion of the small threaded hole C2 is communicated with the exterior of the outer housing H through a V-shaped gas passage P2. Certainly, O rings (not shown) may be sleeved on the large and small bolts B3 and B4 to ensure an air-tight seal between the cylinder body C
and the bolts B3 and B4.
~ith this invention thus explained, it is apparent that numerous modifications and variations can be made without departing from the scope and spirit of this invention. It is therefore intended that this invention be limited only as indicated in the appended claims.
.
Claims (5)
1. A pressure gauge including:
an outer housing:
a rotating shaft journalled in said outer housing and including a pinion fixed on said rotating shaft, and an indicator secured to said rotating shaft for displaying rotational degree of said rotating shaft;
a cylinder, fixed on said outer housing, adapted to be communicated with an interior of a hollow article to be measured, having a piston and a U-shaped piston rod which has generally parallel first and second arms, said first arm extending into said cylinder, said second arm being positioned outside said cylinder and including a rack secured to said second arm for meshing with said pinion of said rotating shaft;
a channel member, secured to said cylinder, having an open-ended guide slot therein for sliding movement of said second arm of said piston rod in said guide slot; and a spring unit connected to said piston in said cylinder for biasing said piston against compressed gas pressure exerted on said piston.
an outer housing:
a rotating shaft journalled in said outer housing and including a pinion fixed on said rotating shaft, and an indicator secured to said rotating shaft for displaying rotational degree of said rotating shaft;
a cylinder, fixed on said outer housing, adapted to be communicated with an interior of a hollow article to be measured, having a piston and a U-shaped piston rod which has generally parallel first and second arms, said first arm extending into said cylinder, said second arm being positioned outside said cylinder and including a rack secured to said second arm for meshing with said pinion of said rotating shaft;
a channel member, secured to said cylinder, having an open-ended guide slot therein for sliding movement of said second arm of said piston rod in said guide slot; and a spring unit connected to said piston in said cylinder for biasing said piston against compressed gas pressure exerted on said piston.
2. A pressure gauge as claimed in Claim 1, wherein said spring unit includes a compression spring sleeved on said piston rod within said cylinder.
3. A pressure gauge as claimed in Claim 1, wherein said spring unit includes a plurality of compression springs of different sizes sleeved on said piston rod and arranged one in another, and wherein said cylinder has an inner end wall on which a stepped cylindrical spring seat is provided for locating said compression springs in said cylinder.
4. A pressure gauge as claimed in Claim 1, wherein said cylinder is formed in a side wall thereof with a pivot hole in which an end of said rotating shaft is inserted rotatably.
5. A pressure gauge as claimed in Claim 4, further comprising a positioning plate secured to said channel member, said positioning plate being formed therein with a circular hole through which the other end of said rotating shaft is inserted rotatably.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000560518A CA1315118C (en) | 1988-03-03 | 1988-03-03 | Compact pressure gauge |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000560518A CA1315118C (en) | 1988-03-03 | 1988-03-03 | Compact pressure gauge |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1315118C true CA1315118C (en) | 1993-03-30 |
Family
ID=4137561
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000560518A Expired - Fee Related CA1315118C (en) | 1988-03-03 | 1988-03-03 | Compact pressure gauge |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1315118C (en) |
-
1988
- 1988-03-03 CA CA000560518A patent/CA1315118C/en not_active Expired - Fee Related
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |