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Publication numberUS187053 A
Publication typeGrant
Publication dateFeb 6, 1877
Publication numberUS 187053 A, US 187053A, US-A-187053, US187053 A, US187053A
InventorsThomas Shaw
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Improvement in pressure-gages
US 187053 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)


. PRESSURE GAGE. No.1,87,053. Patented If'eb. 6,4877.

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Specification forming part of Letters Patent No. 187,053, dated February 6, 1877; application filed October 18, 1876.

with mercury, and in the provision of stopcock and elastic cushion for tube, all for the purpose as hereinafter described.

The object of the invention is to enable the register of low pressures in high-pressure gages, and to secure glass tube tightly without. risk of fracture, and to prevent possible loss of mercury while in transit, and to secure correct working when in operation, and is an improvement on my patent, No. 37,794, of February 24:, 1863, of which'i am sole owner.

In order to enable others to use and practice my invention, I will proceed to describe its construction and operation.

0n reference to the accompanying drawings, which form part of the specification, the sketch represents avertical section through center of gage, of which A is the metal base, provided with plungers O, the weight of which is caused to rest on spring N. The bottom and top of plunger 0 is covered with sheet-rubber, (shown in heavy black line,) to prevent leakage at joints of plunger. screwbutton that impinges on rubber at bottom, and E is an iron disk that impinges on rubber disk at top, being forced down by screw-cap F. The concavity in center of iron disk E forms the mercury-chamber D. B is a nut screwed into base A, and is provided with tapped hole in center to enable attachment to any source of pressure. Brass tube G is soldered to cap F and ring L. Said tube G is slotted in front side to enable the observance of rise of mercury in glass tube H. Figures Iis a' recording the pressure are marked on the outside of brass tube. K is a stop cock, secured concentric in cap M, that screws into ring L. J is a rubber ring, forming acushion for the glass tube in recess in bottom of stopcock K, making it similar to rubber cushion J in center of iron disk E, giving two elastic supports to glass tube H, which lessens the liability to fracture.

The stop-cock K enables a convenient and ready means of shutting 0E mercury while the gage is in transit, and equal facility for opening the mercury-tube to the atmosphere when in use.

The spring N is made of sufficient tension and strength to support the weight of the plunger 0, when loaded with mercury to any desired point.

This improvement enables the immediate registering of any applied pressure beneath plunger 0. Without this improvement the pressure cannot be shown until it has reached a point beyond the weight of plunger and its load of mercury.

It will be evident that the spring 0 can be variously fashioned and applied to effect the same object.

What I claim, and desire to secure by Letters Patent, is

1. The combination, in a mercury steamgage, with the plunger 0, of a spring, N, supporting the plunger and its load of mercury, substantially as and for the purpose set forth.

2. The combination, in a mercury steamgage, with the tube, its cap M, and the mercury-reservoir, of a stop-cock, K, arranged as shown, to retain the mercury within the tube during transit, substantially as set forth.

3. The combination of the rubber cushion J and the gage-tube, beveled at its ends, so that the tube is cushioned in every directiomsubstantially as set forth.




Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2437440 *Jan 4, 1945Mar 9, 1948Duncan L RigdenBalanced pressure gage and switch
US2883995 *Sep 21, 1954Apr 28, 1959Gen ElectricPressure transmitter for liquid metal systems
US4285244 *Feb 13, 1980Aug 25, 1981Honeywell Inc.Non-symmetrical overload protection device for differential pressure transmitter
Cooperative ClassificationG01L7/00