Year: 1885

page_text: We THOMAS ARTHUR ARBOL of Germiston Iron Works Petershill Road Glasgow
in the County of Lanark, Engineer, and JAMES PRINGLE of N° 159 West Scotland
Street Kinning Park in the same City, Engineer, do hereby declare the nature
of this invention to be as follows:-
The invention relates to valve gear in which a single excentric on a crank or
rotating shaft is so connected to a valve or valves for controlling the passage of
steam to and from a cylinder, that, by varying the position of the connections
between the excentric and the valve, the engine may be started stopped and
reversed. The special object being to make such gear more durable and efficient
than heretofore, and to obtain a direct to and fro motion for the valve rod.
In carrying our invention into practice we secure the excentric to the crank or
rotating shaft in any usual way. Around the excentric we fit a block with two
parallel sides arranged to slide between two guides forming segments of circles.
The said guides are connected together and held in position by a suitable frame.
The whole of the mechanism above mentioned is enclosed within a cylindrical strap
which is connected to the valve rod. A guide (or guides) is provided to prevent
the valve rod and cylindrical strap from having anything except direct to and fro
motion. A lever arm or other device is attached to the frame carrying the
segmental guides above mentioned, so as to allow of the position of the said
segmental guides being altered within the cylindrical strap. The lever arm or
other device may be moved by hand or gearing, and it is held in position by set
screws or fasteners. When the segmental guides are moved so as to be at right
angles to the longitudinal axis of the valve rod, or inclined to one side or the other,
the engine will be at rest, or in motion in one or the other direction.
1
J. T. KING,
Per J. Richman,
Agent for the Applicants.

page_text: We THOMAS ARTHUR ARROL of Germiston Ironworks Petershill road, Glasgow,
in the County of Lanark, Engineer and JAMES PRINGLE of 159 West Scotland
Street, Kinning Park, in the same City, 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 :—
The invention relates to valve gear in which a single eccentric on a crank, or
rotating shaft, is so connected to a valve or valves for controlling the passage of
steam to and from a cylinder, that, by varying the position of the connections
between the eccentric and the valve, the engine may be started, stopped and
reversed. The special object being to make such gear more durable and efficient
than heretofore and to obtain a direct to and fro motion for the valve rod.
In carrying our invention into practice we secure the eccentric to the crank, or
rotating shaft in any usual way. Around the eccentric we fit a block with two
parallel sides arranged to slide between two guides forming segments of circles.
The said guides are connected together and held in position by a suitable frame.
The whole of the mechanism above mentioned is enclosed within a cylindrical strap
which is connected to the valve rod. A guide, or guides, is, or, are, provided to
cause the valve rod and cylindrical strap to have direct, or nearly direct, to and fro
motion only. A lever, arm, or other device, is attached to the frame, carrying the
segmental guides above mentioned, so as to allow of the position of the said
segmental guides being altered within the cylindrical strap. The lever, arm, or
other device may be moved by hand or gearing and it is held in position by set
screws or fasteners. When the segmental guides are moved so as to be at right
angles, to the longitudinal axis of the valve rod, or, inclined on one side or the
other the engine will be at rest, or, in motion in the one, or, the other direction.
DESCRIPTION OF THE DRAWINGS.
Figure 1. is a face view Figures 2. 3. and 4 views showing the gear in various
positions and Figures 5 and 6. sections of improved reversing gear under our
invention, a. crank shaft, b, eccentric, c. block with parallel sides, fitting around
the eccentric b.-d segmental guides, connected together by the frame or plate e.,
f. cylindrical strap, g. valve rod connected to f., h. valve, i. guides secured to any
suitable stationary part of the motor j. arm secured to the segmental guides d.-by
set screws k., slot in the arm j. through which the screwed stud m, secured to the
strap passes n lever nut on stud m.
In the Figures 2. 3 & 4. the crank is in the position indicated by the dotted line o.
The guides d. are shewn in figure 2. in the position in which the motor would be
at rest; in figure 3. the guides d. are in position to cause the engine to move to
the right and in figure 4. to the left, as indicated by the arrows. The said
guides d. are placed in the desired position, by means of the arms j. and are
retained there by the nut n.

page_text: Figure 7. is a sectional view of a modification of our improved gear in which
motion is given to the guides d. by means of a worm p, which takes into teeth on
the frame e. connecting the said guides.. The worm p, is free to slide endwise on
the shaft q. from which it receives rotary motion. The said worm and shaft are
provided with feathers and slots, or, the shaft is made square, or otherwise devised
to obtain the desired result.
Figure 8. is a sectional view, of a modification of gear, in which the position of
the segmental guides & is adjusted by means of connecting rods r. attached to a
rocking ariu 8-the rocking arm being itself actuated by the lever and connecting
rod t. In this arrangement the segmental pieces d. act as guides for the strap f.
Figure 9. is a sectional view, in which a guide u. pivotted at v. surrounds the
strap f. an opening w being left in the guide u. to prevent the said guide, from
binding against the valve rod.
In action the eccentric b. causes the block o. to slide to and fro within the
segmental pieces d. and at the same time give to the said segmental pieces a
reciprocating motion the direction of which is regulated by the guides i. acting on
the strap f. which surrounds the said segmental pieces.
It will be obvious that many modifications of our improved gear might be made
and that the eccentric may be reduced in diameter until it becomes a crank pin.
Amongst other advantages obtained by the use of our improved gear, are
simplicity of construction, equal distribution of steam, facility in varying the cut
off according to the position of the seginental guides.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is:-
Valve gear for motive power engines, constructed substantially as set forth.
The combination of the shaft a. eccentric or equivalent b-block c. guides d.
strap f. and guides i. or their equivalent for the purpose set forth.
D11
-
1
1