US3201992A

Gauge casing having plastic hinged blow-out

Abstract

This record has no abstract on file.

US3201992A, drawing sheet 1 — Sheet 1 of 4

Term

Term ended

Expired 24 August 1982, 44.1 years ago.

10 claims: 10 independent, 0 dependent

1
What is claimed is:... 1. In a pressure gage, a hollow casing;gage mechanism within said casing;a front face closing one end of said casing;a cylindrical wall extending from said front face defining an opening in the back end of said casing;an internal peripheral lip and a peripheral groove of greater diameter than said lip on the back end of said cylindrical wall;a plastic back plate closing the back end of said casing, said back plate having a reduced cross section along a line dividing said plate into two segments and forming a hinge joint between said segments;spaced peripheral lips on one segment of said back plate adapted to cooperate with said internal lip;and flange means on said other segment adapted to cooperate with said groove for stationarily fixing said other segment to said casing.
2
In a pressure gage, a casing;gage mechanism within said casing;a front face closing one end of said casing;cylindrical wall extending from said front face defining an opening in the back end of said casing;a plastic back plate closing the back of said casing, peripheral means on said plate interengaging with said wall at said back end, said back plate having a reduced cross section along a line dividing said plate into two segments and forming a hinge joint between said segments;means for fixing one of said segments stationarily to said casing;and an area of the non-stationary segment of less cross section than that of the remainder of said segment.
3
In a pressure gage;a hollow casing;gage mechanism within said casing;a front face closing one. end of said casing;a cylindrical wall extending from said front face defining an opening in the back end of said casing;an internal peripheral lip and a peripheral groove of greater diameter than said lip on the back end of said cylindrical wall;a plastic back plate closing the back end of said casing, said back plate having a reduced cross section along a line dividing said plate into two segments and forming a hinge joint between said segments;spaced peripheral lips bn one segment ;of said back plate adapted 40 to cooperate with said internal lip;flange means on said other segment adapted to cooperate with said groove for stationarily fixing said other segment to said casing;and an area of the non-stationary segment of less cross section than that of the remainder of said segment.
4
In a pressure gage, a hollow casing;gage mechanism within said casing;a front face closing one end of said casing;a cylindrical wall extending from said front face defining an opening in the back end of said casing;a internal peripheral lip and a peripheral· groove of greater diameter than said lip on the back end of said cylindrical wall;a polypropylene back plate closing the back end of said casing, said back plate having a reduced cross section along a line dividing said plate into two segments and forming a hinge joint between said segments;spaced peripheral lips on one segment of said back plate adapted to cooperate with said internal lip;and flange means on said other segment adapted to cooperate with said groove for stationarily fixing said other segment to said casing. .
5
In a pressure gage, a casing;gage mechanism within said casing;a front face closing one end of said casing;a polypropylerie back plate closing the back of said casing, said back plate having a reduced cross section along a line dividing said plate into two segments and forming a hinge joint between said segments;means for fixing one of said segments stationarily to said casing;and an area of the non-stationary segment of less cross section than that of the remainder of said segmerit.
6
In a pressure gage, a hollow casing;gage mechanism within said casing;a front face closing one end of said casing;a cylindrical wall extending from said front face defining an opening in the back end of said casing;an internal peripheral lip and a peripheral groove of greater diameter than said lip on the back end of said cylindrical wall;;a polypropylene back plate closing the . 3 Referring to FIGS. 4 and 5, a back cover plate 37 may be provided for closing the open end 12 of the casing 10. Preferably, this back cover plate is formed from a plastic material having the characteristics in which its crystalline nature permits substantial increases in strength through orientation or stretching, has high elongation;beyond the yield point, has resistance to stress cracking, and forms a relatively tough skin during molding or extruding. Although flexible plastics such as vinyls and polyethylenes possess to some degree the above desirable characteristics, a plastic such as polypropylene does possess the desired characteristics and is ideally suited for the purposes intended. The plate 37 may be generally circular in form and may include a groove 38 producing a cross section at the bottom of the groove of substantially less thickness than the thickness of the remainder of the plate. With such a groove 38, the plate is divided into two segments 39 and 40 which can be flexed without danger of deteriorating the material at the bottom of groove 38. In fact, continued flexing of the segments 39 and 40 actually increases the strength of the joint at groove 38, thereby providing a hinge point of the plastic material forming the plate 37. The peripheral edge 41 of the segment 40 may include spaced lips 42 and 43 (FIG. 3) between which is located a groove 44 of less diameter than that of lips 42, 43, which lips 42, 43 straddle the lip 35 on the casing 10 to hold the segment 40 in.closed position. The peripheral edge 45 of the segment 39 is flanged at 46, said flange being adapted to be received within the groove 36 within the casing 10. A depending extension 47 of flange 46 is adapted to be received within a slot 48 (FIG. 1) of casing 10, and screws are adapted to pass through holes 49' therein which mate with similar threaded holes within casing 10. Referring to FIGS. 1, 5 and 6, the segment 40 may include an area 49 of generally circular extent having a reduced cross section toward the center of the area. This construction provides a diaphragm effect to the segment 40 so that upon the buildup of pressure within the casing 10, the circular area 49 will bulge outwardly (FIG. 6), thereby withdrawing the peripheral edge 41 of segment 40 inwardly arid thereby releasing the iritermeshing relationship between the lips 35, 42 and 43 so that the segment 40 can pivot about hinge joint or groove 38, thus releasing the pressure within the casing 10. A slot 50 may be provided in the segment 40 within which a screwdriver blade or the like may be inserted to open the segment 40 when it is desired to adjust the gage mechanism within chamber 15. Manually pressing inwardly on the area 49 will effect closing and latching of the segment 40 in closed position. As shown in FIGS. 4, 5 and 6, the hinge joint provided by the groove 38 is below the center of the back plate. In some gages, this may make adjustment of the gage mechanism difficult. Referring to FIG. 7, it is within the scope of the present invention to reverse the plate so that the depending flange 47 is at the top of the back plate if such location more readily facilitates adjustment of the gage mechanism. Furthermore, in the form shown in FIG. 7, any water that may collect therein will drain out. Should the Bourdon tube 16 fail under high pressure, the sudden release of this pressure will force segment 40 65 open, relieving it, and the guard board 34 that is spaced from the gage will intercept any parts of the gage mechanism within the casing 10 that may fly out and possibly injure someone in the vicinity. Although the various features of the new and improved gage and back plate have been shown and described in detail to fully disclose one embodiment of the invention, it will be evident that changes may be made in such details and certain features may be used without others 3,201,992 back end of said casing, said back plate having a reduced cross section along a line dividing said plate into two segments and forming a hinge joint between said segments;spaced peripheral lips on one segment of said back plate adapted to cooperate with internal lip;flange means on said other segment adapted to cooperate with said groove for stationarily fixing said other segment to said casing;and an area of the non-stationary segment of less cross section than that of the remainder of said segment.
7
Apparatus comprising in combination, a board;bosses mounted on said board;a pressure gage including a casing having bosses adapted to be mounted on the bosses on said board to space said casing a substantial distance from said board;gage mechanism within said casing;a front face closing one end of said casing;a cylindrical wall extending from said front face defining an opening in the back end of said casing;an internal peripheral lip and a peripheral groove of greater diameter than said lip on the back end of said cylindrical wall;a plastic back plate closing the back end of said casing, said back plate having a reduced cross section along a line dividing said plate into two segments and forming a hinge joint between said segments;spaced peripheral lips on one segment of said back plate adapted to cooperate with said internal lip;and flange means on said other segment adapted to cooperate with said groove for stationarily fixing said other segment to said casing.
8
Apparatus comprising in combination, a guard board;bosses mounted on said board;a pressure gage including a casing having bosses adapted to be mounted on the bosses on said board to space said casing a substantial distance from said board;gage mechanism within said casing;a front face closing one end of said casing;a cylindrical wall extending from said front face defining an opening in the back end of said casing;a plastic back plate closing the back of said casing, peripheral means on said plate interengaging with said wall at said back end, said back plate having a reduced cross section along a line dividing said plate into two segments and forming a hinge joint between said segments;means for fixing one of said segments stationarily to said casing and an area of the non-stationary segment of less cross section than that of the remainder of said segment, said guard board serving to contain portions of said gage mechanism upon pivotal movement of said back plate during pressure blow out.
9
Apparatus comprising in combination, a board;bosses mounted on said board;a pressure gage including a casing having bosses adapted to be mounted on the bosses on said board to space said casing a substantial distance from said board;gage mechanism within said casing;a front face closing one end of said casing;a cylindrical wall extending from said front face defining an opening in the back end of said casing;an internal peripheral lip and a peripheral groove of greater diameter than said lip on the back end of said cylindrical wall;a polypropylene back plate closing the back end of said g casing, said back plate having a reduced cross section along a line dividing said plate into two segments and forming a hinge joint between said segments;spaced peripheral lips on one segment of said back plate adapted to cooperate with said internal lip;flange means on said 10 other segment adapted to cooperate with said groove for stationarily fixing said other segment to said casing;and an area of the non-stationary segment of less cross section than that of the remainder of said segment.
10
In a pressure gage, a hollow casing; gage mecha15 nism within said casing; a front face closing one end of said casing; a cylindrical wall extending from said front face defining an opening in the back end of said casing; an internal peripheral lip and a peripheral groove of greater diameter than said lip on the back end of said 20 cylindrical wall; a back plate made from a plastic, the crystalline nature of which increases in strength through orientation and stretching, closing the back end of said easing, said back plate having a reduced cross section along a line dividing said plate into two segments and 25 forming a hinge joint between said segments; spaced peripheral lips on one segment of said back plate adapted to cooperate with said internal lip; and flange means on said other segment adapted to cooperate with said groove for stationarily fixing said other segment to said casing. 30 11. In a pressure gage, a casing; gage mechanism with- in said casing; a front face closing one end of said casing; a cylindrical wall extending from said front face defining an opening in the back end of said casing; a back plate made from a plastic, the crystalline nature of which in35 creases in strength through orientation and stretching, closing the back of said casing, peripheral means on said plate interengaging with said wall at said back end, said back, plate having a reduced cross section along a line dividing said plate into two segments and forming a 40 hinge joint between said segments; means for fixing one of said segments stationarily to said casing; and an area of the non-stationary segment of less cross section than that of the remainder of said segment. 40 References Cited by the Examiner UNITED STATES PATENTS 448,449 3/91 Marsh________________73—411 1,488,034 3/24 Crocker et al._______ 73—416 50 2,952,039 9/60 Jaffe. RICHARD C. QUEISSER, Primary Examiner. DAVID SCHONBERG, Examiner. UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3,201,992 August 24, 1965 Harry W. Hoff, Jr. It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below. Column 2, line 58, for ”24” read -- 25 --; column 3, line 23, for point read -- joint --; column 4, line 62, before a” insert -- cylindrical wall extending from said front face defining an opening in the back end of said casing· line 63, before said” insert -- peripheral means on said* plate interengagmg with said wall at said back end -column 5, line 5, after with insert -- said ’ Signed and sealed this 5th day of April 1966. EAL) test:NEST W. SWIDER esting Officer EDWARD J. BRENNER Commissioner of Patents

40 paragraphs in 4 sections, as filed

Aug. 24, 1965 h. w. hoff, jr 3,201,992

GAUGE CASING HAVING PLASTIC HINGED BLOW-OUT

Filed Nov. 30, 1961 2 Sheets-Sheet 1

Aug. 24, 1965

H. W. HOFF, JR

3,201,992

GAUGE CASING HAVING PLASTIC HINGED BLOW-OUT

United States Patent Office „ · Δ3’2012

Patented Aug. 24, 1965

3,201,992

GAUGE CASING HAVING PLASTIC HINGED BLOW-OUT

Harry W. Hoff, Jr., Quakertown, Pa., assignor to Ametek, Inc., a corporation of Delaware

Filed Nov. 30, 1961, Ser. No. 155,972

Claims. (Cl. 73—-416)

The present invention relates to pressure gages and particularly to a new and improved back construction for relieving pressure that may develop within the gage case upon the failure of the pressure responsive element therein.

It is known to provide hinged back plates for pressure gages. These back plates ordinarily are provided with spring means for maintaining them in closed condition. Consequently, when it is desired to make adjustments to the internal mechanism that is only accessible from the back, it is necessary to hold the spring-closed back cover open with one hand while making the adjustment with the other hand. This presents an awkward arrangement since generally any adjustment usually requires both hands.

The principal object of this invention is to provide a back face cover for a pressure gage that will automatically open upon the buildup of pressure within the gage casing and remain open until manually closed.

Another object of the invention is to provide such a back face for a pressure gage that has an integral part thereof in the form of a hinged construction.

Still another object of the invention is to provide such a gage back cover that includes as an integral part thereof an edge construction that will cooperate with an intermeshing construction on the gage casing.

Still another object of the invention is to provide such a gage back cover that includes a pressure sensitive area which, when subjected to pressure within the casing, will separate the intermeshing connection between the back face cover and the casing.

Still another object of the invention is to provide such a gage and back cover plate with mounting means for mounting the gage on a back board sufficiently far from the back board so that the back cover plate can open to relieve pressure within the casing and such that the back board will intercept any parts that might be blown from the interior of the case upon the failure of the pressure responsive element of the gage.

In one aspect of the invention, the gage casing may be provided with a substantially cylindrical back end portion on which may be located mounting bosses for cooperation with spacers fixed to a mounting board.

In another aspect of the invention, the casing may be provided with a circular opening in its back leading to the interior of the casing, having a thin lip formed on the inner peripheral edge of the circular opening and a groove of greater diameter in said inner peripheral edge inwardly of said lip construction.

In another aspect of the invention, the back cover plate may be substantially circular in form and made from a plastic material in which its crystalline nature permits substantial increases in strength through orientation or stretching, has high elongation beyond the yield point, has resistance to stress cracking, and forms a relatively tough skin during molding or extruding. Although flexible plastics such as vinyls and polyethylenes possess to some degree the above desirable characteristics, a plastic material of exceptional qualities is one such as polypropylene.

In another aspect of the invention, a substantially circular plastic back cover plate made from such material may include a groove reducing the cross sectional thickness of the plastic material along a segmental line. Flexing the segmental parts of the plate on each side of the groove forms a hinge of the plastic material itself.

In still another aspect of the invention, the peripheral edge of the back plate on one side of the hinge groove 5 may be provided with two spaced peripheral lips forming a peripheral groove therebetween that receives the lip on the inner peripheral circular edge of the back opening of the casing when the back plate is closed.

In still another aspect of the invention, the peripheral 10 edge of the back plate on the opposite side of the hinge groove may include a flange for fitting within the groove interiorly of the lip on the casing opening.

A still further aspect of the invention may include an area portion of the back plate segment that opens, which 15 will act as a diaphragm tending to unlatch the openable portion of the back plate upon the buildup of pressure within the casing.

The above, other objects and novel features of the invention will become apparent from the following speci20 fication and accompanying drawings which are merely exemplary.

In the drawings:

FIG. 1 is an enlarged sectional elevational view taken substantially along line 1—1 of FIG. 2 and showing a 25 pressure gage to which the principles of the invention have been applied;

FIG. 2 is a front elevational view, on a reduced scale, of the gage shown in FIG. 1;

FIG. 3 is an enlarged sectional view of a detail of the 30 back cover plate;

FIG. 4 is an edge view of the back cover plate;

FIG. 5 is a view of the back plate as seen when looking in the direction of the arrows in FIG. 4 on a reduced scale;

FIG. 6 is a section of a detail of the back cover plate; and

FIG. 7 is similar to FIG. 6 but shows a modification of the invention.

Referring to the drawings and particularly to FIGS. 1 40 and 2, the principles of the invention are shown as applied to a Bourdon type of pressure gage including a casing 10 of generally hollow cylindrical form and having both ends 11 and 12 open. A partition 13 divides the casing into two compartments 14 and 15. The usual 4ό pressure gage mechanism is housed within the compartment 15, and it is shown as including a Bourdon tube 16, the interior of which is connected to a threaded fitting 17 adapted to be connected to a line 18 containing fluid, the pressure of which is to be measured. The casing 10 δυ may be made of any material, but is shown as being an injection molded plastic casing. The end of the Bourdon tube 16 opposite that including the fitting 17 is closed at 19, said closure being connected to a rigid element 20, one end of which is pivotally connected to an arm °° 21. The opposite end of arm 21 is pivoted to another link 22 which, in turn, is connected to a quadrant 23. The quadrant 23 is provided with a toothed sector 24 that meshes with a pinion 24 fixed to a spindle 26 on which an indicating hand 27 is fixed, as is well known. A dial 28 is fixed to the partition 13 within chamber 14, and a bezel 29 holds a transparent closure 30 in a manner to close the opening 11 in the casing 10.

The casing 10 may be provided with bosses 31 having passages therethrough for receiving bolts 32 that thread b5 into bosses or spacers 33 fixed to a mounting guard board 34 on which the gage is mounted in spaced relation for a purpose to be described later.

Adjacent the opening 12 may be provided a peripherally extending lip 35 (FIG. 3) and a groove 36 of 70 greater diameter than the diameter of the lip 35. The lip 35 and the groove 36 extend completely around the inner peripheral surface of the opening 12.

3,201,992 ; .

without departing from the principles of the invention.

Contents4

Every citation, both ways

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Document	Office	Kind	Date
15597261	United States of America	A	1961-11-30
US19610155972	–	–	–

Gauge casing having plastic hinged blow-out

Abstract

Term

GAUGE CASING HAVING PLASTIC HINGED BLOW-OUT

H. W. HOFF, JR

GAUGE CASING HAVING PLASTIC HINGED BLOW-OUT

GAUGE CASING HAVING PLASTIC HINGED BLOW-OUT

Priority claims2

Numbers

Titles

Classification