Automatic Stop Gear for Fluid Pressure Engines.
Year: 1893

page_text: Date of Application, 1st June, 1893
Complete Specification Left, 1st Mar., 1894-Accepted, 28th Apr., 1894
PROVISIONAL SPECIFICATION.
Automatic Stop Gear for Fluid Pressure Engines.
I, WILLIAM BRUCE THOMPSON, of Ellangowan, Dundee, in the County of
Forfar, N.B. Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to Improvements in Automatic Stop Gear for Fluid Pressure
Engines, such as for example steam engines for propelling vessels. In many cases it
is most desirable that the speed, that is to say the number of revolutions per minute
of an engine crank shaft, should not exceed a given limit.
In carrying out my invention according to one modification as applied to marine
engines I apply a spring, or its equivalent to the reversing lever of the steam
reversing cylinder, or to the main reversing lever where such supplementary
cylinder is not used; the object of the spring being to draw, or to tend to draw the
reversing lever from the foregoing to the centre notch.
Preferably on the crank shaft is fixed a spur or a bevel wheel, or other equivalent,
which is used to drive the well known spur wheel oil or fluid circulating pump
frequently used for crank bearings. A pipe from the pump leads the oil to a cylinder
of special construction, from thence to a reservoir after which it returns again to the
pump. Between the cylinder and the reservoir is placed a cock or other suitable
appliance for regulating the flow of the fluid; the less the passage the greater the
pressure of such fluid within the cylinder, and inversely. The cylinder is provided
with a piston and piston rod, the end of such rod terminating in an incline which, at
a certain position of the piston due to the pressure of the fluid or the speed of the
engine, causes it to lift the finger of the reversing lever from the forward notch and
thus permits the spring previously referred to, to draw the reversing lever to mid
A spring is employed to cause the piston and its rod to tend towards the in
end of the cylinder.
gear.
1 may provide means to cause the apparatus to operate, in order that it may be
periodically tested without stopping the engine.
Dated this 30th day of May 1893.
GEO. C. DOUGLAS & Co.,
41, Reform Street, Dundee, Agents for Applicant.
COMPLETE SPECIFICATION.
Automatic Stop Gear for Fluid Pressure Engines.
I, WILLIAM BRUCE THOMPSON, of Ellangowan, Dundee, in the County of
Forfar, N.B. 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 :-
My invention relates to Improvements in Automatic Stop Gear for Fluid Pressure
Engines, such as for example steam engines for propelling vessels. In many cases
it is most desirable that the speed, that is to say the number of revolutions per
minute of an engine crank shaft, should not exceed a given limit.
In order that my invention may be properly understood and readily carried into
effect, I have hereunto appended two explanatory sheets of drawings in the several
figures of which corresponding parts are marked with the same numerals of
reference

page_text: Figure 1. (Sheet 1.) illustrates in a general view, how my invention may be
applied to a marine engine; and
Figures 2. 3. and 4. respectively show to a larger scale, a view of the regulating
apparatus looking on A. (Figure 3.) in the direction of the arrow; a section at B. B.
(Figure 2.); and a section at C. C. (Figure 3.), of the regulating plug.
Figures 5. and 6. (Sheet 2.) illustrate another modification of my invention
specially applicable to "round about" reversing gear.
In carrying out my invention according to one modification, as applied to marine
engines, I apply a spring 10, or its equivalent, to the reversing lever 11. of the
steam reversing cylinder 12, or to the main reversing lever, where such supple-
mentary cylinder is not used; the object of the spring being to draw, or to tend to
draw the reversing lever from any of the foregoing notches 13. to the central
notch 14.
Preferably on the crank shaft 15, is fixed a spur or bevel wheel 16, or other
equivalent, I have shown a spur wheel-which is used to drive the well known
spur wheel oil or fluid circulating pump 17. frequently used for crank bearings. A
pipe 18. from the pump leads the oil to a cylinder 19. of special construction, from
thence through a pipe 20. to a reservoir 21, after which it returns again through the
pipe 22. to the pump 17. Between the cylinder 19. and the reservoir 21. is placed
a cock or other suitable appliance 23. for regulating the flow of the fluid; the less
the passage the greater the pressure of such Huid within the cylinder, and inversely.
The cylinder is provided with a piston 24. and piston rod 25, the end of such rod
terminating in an incline 26. which, at a certain position of the piston due to the
pressure of the fluid, or the speed of the engine, causes it to lift the finger 27. of the
reversing lever 11. from any of the forward notches it may be in, and thus permits
the spring 10. previously referred to, to draw the reversing lever 11. to mid gear.
A spring 28. is employed to cause the piston and its rod to tend towards the in end
of the cylinder as shewn in Figure 3.
The mechanism operates in the following manner :-If the finger 27. be in any
of the foregoing notches and if the crank shaft be rotating at its normal speed and
the passage 29. fully open, the pump 17. causes the oil to circulate through the
pipe 18. past the cylinder 19, through the pipe 20, reservoir 21. and from thence
back through the pipe 22. to the aforesaid pump; but if such passage 29. be con-
stricted say by means of the adjustable plug 30-then the pressure in the pipe 18.
will be increased and the piston 24. will be moved along the cylinder 19. against the
pressure of the spring 28. until the incline 26, which is jointed at 31, pushes the
finger 27. out of such notch and keeps it clear, thus allowing the spring 10. to pull
the reversing lever towards its central position, where it is kept by the finger falling
into the central notch 14. The connecting rod 32. coupled to the reversing lever
shaft 33. actuates the steam valve in the known way. By thus adjusting the flow of
oil through the passage 29. by means of the plug 30; the slide valve may be auto-
matically drawn to mid position and the engine stopped when its speed exceeds a
given limit. 34. is an index whose motion synchronizes with that of the plug 30,
and it may be marked to indicate the position of such plug and thus its position for
given maximum speeds beyond which the crank shaft should not rotate.
screw 35. is for the purpose of adjusting the pressure of the spring 28, thus
regulating the resistance to longitudinal motion of the piston 24.
The
In some cases the engine is reversed in another known way-sce Figures 5. and 6.
by means of an engine 36. actuating a worm 37. and worm wheel 38.—which
is always made to rotate in the one direction-the cod piece of the link being
coupled by means of a rod to such wheel at 39. The supply of steam to the
cylinders 40. is controlled by a slide valve 41. of a well known type, in such a
manner that when the valve is fully open the engines are in motion and when
closed they are stopped. As shewn in the drawings the pin 39. is in the fore-
going position and therefore the main engine is moving forward, the slide valve 41.
is closed and consequently the engine 36. is stopped. To stop or reverse the main
engine the handle 42 should be depressed and the valve 41. opened until its

page_text: other extremity 43. comes in contact with the knife edge 44. of the eccentric
rod 45. actuated by the eccentric 46. which rotates with the worm wheel 38.
As the worm wheel rotates the valve 41. is gradually closed by the action of the
aforesaid mechanism, it being fully closed when the cod piece in the link is in
mid position.
To cause the engine to automatically stop when going ahead, the cylinder 19.
and its appurtenances, namely the oil pump 17; pipes 18, 20, and 22; regulator 23.
and reservoir 21. are employed as previously described.
This particular modification of the mechanism operates in the following manner.
If the main engine be moving forward and at its normal speed the apparatus
will be in the position shewn in Figures 5. and 6. but if that speed be exceeded
the piston 24. will be depressed, the valve 41. opened and the worm wheel made
to rotate in the direction of the arrow, until such valve is closed by the eccentric
rod 45. and intervening mechanism, such closure taking place when the valve
of the main engine is in mid position, in this manner causing such engine to stop.
I wish it to be particularly understood that I do not limit myself to the
precise details of construction herein before described and illustrated on the
annexed drawings, but that I hold myself free to make such changes and
alterations as conform with the disposition and scope of my invention.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is :-
:-
(1) In apparatus for automatically stopping fluid pressure engines when a
given speed is exceeded, the mode of actuating the piston 24. and the mechanism
connected therewith substantially as hereinbefore described.
(2) In apparatus for automatically stopping fluid pressure engines when a given
speed is exceeded, the combination of stop gear substantially as described and
illustrated by Figures 1. 2. 3. and 4.
(3) In apparatus for automatically stopping fluid pressure engines when a given
speed is exceeded, the combination of stop gear substantially as described and
illustrated by Figures 5. and 6.
(4) The mode of drawing the reversing lever 11. towards its central position
by means of the spring 10, or its equivalent, substantially as described.
(5) The use of the oil pump 17, for the purposes described.
(6) The combination of the incline 26. and the reversing lever finger 27,
substantially as described and for the purposes as set forth.
(7) The use of the screw 35, for regulating the pressure of the spring 28, as
described.
(8) The combination of the eccentric 46, rod 45, handle 42, and valve 41,
substantially as described and for the purposes set forth.
Dated this 27th day of February 1894.
GEO. C. DOUGLAS & Co.,
41, Reform Street, Dundee, Agents for Applicant.