Improvements in Safety Valves.
Year: 1895

page_text: Date of Application, 30th Jan.. 1895
Complete Specification Left, 30th Oct., 1895-Accepted, 30th Nov., 1895
PROVIDIUNAL SPECIFICATION.
Improvements in Safety Valves.
I, ROBERT COCKBURN, of Cumbrae House, Dumbreck, in the City of Glasgow,
Engineer, do hereby declare the nature of this invention to be as follows :---
In spring-loaded safety valves more especially when grouped so that the com-
pression on the springs is maintained by a tie-bar or cross-head bearing on the
ends of the springs any slight inequality of pressure results in buckling of the
spring in relation to the valve spindle which it surrounds and consequently
the spindle is jammed in its guides or the valve is tilted on its seat and permits
of escape of steam before the pressure due to the load on the valve is attained.
My invention has for its object to overcome this objection, and to that end it
consists in forming a joint in the valve spindle or stem such that in the event of
buckling of the spring the upper portion of the spindle may be free to tilt or
oscillate on the lower portion which bears on the valve and is supported by the
guide. The joint is preferably formed by a stud-like projection on one portion of
the spindle entering a socket in the other portion the meeting faces being curved
or made like knife edges a ball and socket or otherwise to transmit the pressure
of the spring through the axis of the jointed spindle so that the full pressure of
the spring is applied on the valve.
Dated this 29th day of January 1895.
WALLACE FAIRWEATHER,
Chartered Patent Agent,
2 Saint Vincent Street, Glasgow, Agent for the Applicant.
I, ROBERT COCKBURN, of Cumbrae House, Dumbreck, in the City of Glasgow,
Engineer, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:―
In spring-loaded safety valves more especially when grouped so that the com-
pression ou the springs is maintained by a tie bar or crosshead bearing on the ends
of the springs any slight inequality of pressure results in buckling of the spring in
relation of the valve spindle which it surrounds and consequently the spindle is
jammed in its guides or the valve is tilted on its seat and permits of escape of
steam before the pressure due to the load on the valve is attained.
My invention which is illustrated by the accompanying drawing has for its
object to overcome this objection, and to that end it consists in forming a joint
at A in the valve spindle or stem B such that in the event of buckling of the
spring C the upper portion of the spindle B may be free to tilt or oscillate on the
lower portion which bears on the valve D and is supported by the guide E.
The joint at A is preferably formed by a stud-like projection 6 on one portion
of the spindle entering a socket in the other portion the meeting faces being

page_text: curved or made like knife edges, a ball and socket, or otherwise to transmit the
pressure of the spring C through the axis of the jointed spindle B so that the full
pressure of the spring is applied on the valve D.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what mauner the same is to be performed, I declare that what I
claim is :-
1. In spring-loaded grouped safety valves, forming the valve spindles or stems
each with a joint in its length substantially as and for the purpose set forth.
2. In a spring-loaded safety valve a valve spindle' or stem formed in two parts
the one portion having a projection, entering a socket in the .other portion
substantially as and for the purpose set forth.
Dated this 29th day of October 1895.
WALLACE FAIRWEATHER,{
Chartered Patent Agent,
62 Saint Vincent Street, Glasgow, Agent for the Applicant.