Pressure measuring arrangement

• US 20040040383A1
• Filed: 08/29/2003
• Published: 03/04/2004
• Est. Priority Date: 10/19/2000
• Status: Active Grant

• Current Assignee: Endress + Hauser GmbH + Company KG (Endress+Hauser AG)
• Original Assignee: Endress + Hauser GmbH + Company KG (Endress+Hauser AG)
• Inventors: Banholzer, Karl-Heinz, Hegner, Frank, Flogel, Karl, Rosskopf, Bernd
• Granted Patent: US 6,935,179 B2
• Time in Patent Office: Days
• US Class Current: 73/712
• CPC Class Codes: G01L 19/0046 using isolation membranes G01L13/026 and G01L19/0645 take precedence
• CPC Class Codes: G01L 9/0075 using a ceramic diaphragm, e.g. alumina, fused quartz, glass

Abstract

The invention relates to a pressure measuring arrangement comprising a pressure measuring cell (5) which is fed by a pressure corresponding to the pressure which is to be measured by a pressure tube (3) filled by a pressurised liquid; at least one pressure recording unit (25, 45) is arranged separately from said cell, said unit being impinged upon by a pressure which is to be measured during operation, producing a pressure corresponding to the pressure which is to be measured via a pressure line (33, 55) filled by a liquid; a connection between the pressure tube (3) and the pressure line (33, 55). A modular design and a large amount of flexibility is obtained in respect of the spatial arrangement of the pressure measuring cell (5) and the pressure recording unit (25, 45). The connection consists of a base body (27, 57, 59, 61, 62, 77, 79) wherein at least one end section of the pressure line (33, 55) is arranged, in addition to a pressure screw (35, 65) through which the pressure tube (3) passes and is secured by a fixing element arranged on a side which is oriented towards the base body of the pressure screw (35, 65). Said pressure screw has a thread which enables it to be screwed onto base body (27, 57, 59, 61, 62, 77, 79) in such a way that the pressure tube (3) and the pressure line (33, 55) are connected, and the connection is effectively sealed between the pressure tube (3) and the pressure line (33, 55).

Claims

1. A pressure measuring arrangement, having

a pressure measuring cell (5),

to which a pressure corresponding to a pressure to be measured is delivered via a fluid-filled pressure tube (3);

at least one pressure recording unit (25, 45) disposed separately therefrom,

on which in operation a pressure to be measured acts, and

which makes a pressure corresponding to the pressure to be measured available via a fluid-filled pressure line (33, 55); and

a connection between the pressure tube (3) and the pressure line (33, 55), which connection includes;

a base body (27, 57, 59, 62, 77, 79), in which at least one end portion of the pressure line (33, 55) is disposed,

a pressure screw (35, 65),

through which screw the pressure tube (3) is passed and is secured there by means of a mount disposed on a side of the pressure screw (35, 65) oriented toward the base body, and

which screw has a thread by means of which it is screwed onto the base body (27, 57, 59, 62, 77, 79), in such a way that

the pressure tube (3) and the pressure line (33, 55) communicate, and

sealing of the connection between the pressure tube (3) and the pressure line (33, 55) is effective.

3. The pressure measuring arrangement of claim 1 or 2, in which

the thread is a male thread,

which is screwed into a recess (41) in the base body (27, 28, 57);

the pressure line (33, 55) or the pressure tube (4) leads to the recess (41);

the mount (39) is a ring mechanically solidly connected to the pressure tube (3) or to the pressure line (4),

which in the mounted state rests sealingly, with an end face oriented toward the pressure screw (35), on an end face of the pressure screw (35) oriented toward the base body.

4. The pressure measuring arrangement of claim 3, in which

the pressure tube (3) or the pressure line (34) tapers conically on the outward end,

and rests sealingly on a conical inside face of the same shape in the region of the orifice of the pressure line (33, 55) or of the pressure tube (4).

5. The pressure measuring arrangement of claim 1, in which

the pressure screw (65) is a union nut,

which takes the form of a cylinder closed on one end by a radially inward-extending shoulder (67);

the cylinder has a female thread, which is screwed onto a male thread of the base body (59, 61, 62, 77, 79); and

the pressure tube (3) is passed through the shoulder (67) into the pressure screw (67).

6. The pressure measuring arrangement of claim 5, in which

the pressure line (55) discharges into the base body (59) and is connected tightly and mechanically solidly to it;

the pressure tube (3) is connected tightly and mechanically solidly to an annular disk (69) coaxially surrounding the pressure tube;

an end face of the annular disk (69) rests on an annular-disklike inside face of the shoulder (67); and

the annular disk (69) is pressed by the pressure screw (65) in the direction toward the base body.

7. The pressure measuring arrangement of claim 6, in which

between the annular disk (69) and the base body (59), a sealing element (73) annularly surrounding the pressure tube (3) is provided, by which a hollow chamber, defined by the annular disk (69), the sealing element (73), and the base body (59), and surrounding the pressure tube (3) is sealed off.

8. The pressure measuring arrangement of claim 5, in which

the pressure tube (3) is widened by crimping in the interior of the pressure screw (65);

the pressure line (55) is introduced into the pressure tube (3);

the pressure line (55) is passed through the base body (62) and mechanically solidly connected to it;

the pressure line (55) tapers conically on the outward end; and

a crimped-on end portion (74) of the pressure tube (3) is fastened sealingly between a conical jacket face (75, 78), disposed in the interior of the pressure screw (65), and the conical portion of the pressure line (55), in that the jacket face (75, 78) is pressed against the pressure line (55) by the pressure screw (65) in the direction toward the base body.

9. The pressure measuring arrangement of claim 5, in which

a clamping cone (85) is disposed on the end in the pressure screw (65),

which clamping cone has an outer jacket face (87) that tapers conically in the direction toward the base body,

which jacket face grips the pressure tube (3) and

in which the pressure tube (3) is fastened,

in that the clamping cone (85) is pressed inward with its conical jacket face by the pressure screw (65) into an inner jacket face (89) of the base body (77, 79) that is oriented toward the clamping cone (85) and tapers conically in the direction remote from the clamping cone.

10. The pressure measuring arrangement of claim 9, in which

on an end of the base body (79) facing the pressure screw (65), a second pressure screw (91) of identical form is provided, through the pressure line (55) is introduced into a bore (83) penetrating the base body (79),

in which bore a second clamping cone (93) is disposed on the end,

which clamping cone has an outer jacket face (95) tapering conically in the direction toward the base body,

which jacket face grips the pressure line (55) and

in which the pressure line (55) is fastened,

in that the second clamping cone (93) is pressed inward with its conical jacket face (95) by the second pressure screw (93) into an inner jacket face (97) of the base body (79) oriented toward the second clamping cone (93) and tapering conically in the direction remote from the clamping cone.

2. A pressure measuring arrangement, having

a pressure measuring cell (5),

to which a pressure corresponding to a pressure to be measured is delivered via a fluid-filled pressure tube (4);

at least one pressure recording unit (45) disposed separately therefrom,

on which in operation a pressure to be measured acts, and

which makes a pressure corresponding to the pressure to be measured available via a fluid-filled pressure line (34); and

a connection between the pressure tube (4) and the pressure line (34), which connection includes;

a base body (28), in which at least one end portion of the pressure line (34) is disposed,

a pressure screw (35, 65),

through which screw the pressure line (34) is passed and is secured there by means of a mount disposed on a side of the pressure screw (35, 65) oriented toward the base body, and

which screw has a thread by means of which it is screwed onto the base body (28), in such a way that

the pressure tube (4) and the pressure line (34) communicate, and

sealing of the connection between the pressure tube (4) and the pressure line (34) is effective.