Improvements in or connected with Devices for Transmitting Move- ment to the Valve-operating Shaft of Four-stroke Gas, Petroleum, and like Motors.
Year: 1898

page_text: Date of Application, 9th Nov., 1898-Accepted, 2nd Sept., 1899
Improvements in or connected with Devices for Transmitting Move-
ment to the Valve-operating Shaft of Four-stroke Gas, Petroleum,
and like Motors..
A communication by THE GESELLSCHAFT FÜR AUTOMOBILWAGENBAU, GESELLSCHAFT
MIT BESCHRÄNKTER HAFTUNG, of Nuremberg, in the Empire of Germany,
Manufacturers.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of The Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester,
both in the County of Lancaster, 118, New Street, Birmingham, in the County
of Warwick, and 322, High Holborn, in the County of Middlesex, Civil
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 four-stroke motors with vertical cylinders, as a rule, the rotation of the
horizontal crank shaft has to be conveyed by means of gearing in the ratio 1:2 to
a vertically arranged valve-operating shaft. Although for this purpose the use
of helical gear is preferable, their use has hitherto encountered considerable
difficulties, as such helical wheels in order to produce a rapid and noiseless
running, must not only be mounted on the machine frame, but also be enclosed
in an oil tight casing in which they can travel entirely in an oil bath. The
present invention endeavours to meet both requirements by an improved arrange-
ment of astonishing simplicity as against the forms of construction hitherto
known and which also renders possible a very easy mounting of the separate
parts.
For this object the outside diameter of the smaller helical wheel mounted on
the crank shaft is made smaller than the diameter of the shaft and formed in
one piece with the crank shaft. By this means it is possible to mount or
support the crank shaft at both sides of the helical wheel in such a way that the
mutual bearing cups are formed together in one piece and form parts of a
common cylinder which may be pushed over the smaller helical wheel on the
shaft. The said bearing cup is provided at the point of engagement of the two
helical wheels with a slot through which engages the larger helical wheel keyed
on the valve-operating shaft. The shaft is also mounted in two places, one of
them being in the cover closing the casing. The whole arrangement forms a
casing closed on all sides which may be filled with oil so that the helical wheels
run entirely in an oil bath:
In gas and steam engines the valve operating shaft is understood to mean
those shafts from which the valves mounted on the cylinder are governed or
moved. This movement is as a rule effected by means of valve spindles and
levers which are operated from cams or the like mounted on the valve operating
shaft. The valve operating shaft shown in the drawing has been exaggerated
simply for the sake of clearness.

page_text: In the accompanying drawings.
Figure 1 is an elevation of a vertical motor having a form of construction
of this improved arrangement, whilst,
Figures 2 and 3 show the improved arrangement on an enlarged scale.
The horizontal crank shaft 1 is mounted in two places in the machine frame 2
and at one place is formed into a helical wheel 3, Figure 3, the outer diameter
of which is slightly smaller than the diameter of the shaft. A bearing cup 4
in the form of a single cylinder is placed on the crank shaft 1 over the
helical wheel 3, and is mounted with its external end 5 in a stuffing box 6.
In this manner a solid bearing is obtained for the crank shaft 1 at both sides
of the helical wheel 3 by the bearing surfaces 7 and 8 of the cup 4.
A helical wheel 10 mounted on the valve-operating shaft 9 engages with the
wheel 3 and the number of teeth of this wheel 10 is double that of the wheel 3
so as to give a ratio of transfer of 1:2, the teeth being set at an angle of 45°
to allow of this. For this purpose the bearing cup 4 is provided at the point
of engagement of the two helical wheels with a slot 11 through which the
helical wheel 10 engages.
In order to obtain an entirely oil tight casing, the stuffing box 6 is extended
at one side to form a casing 12 which encloses completely, both beneath and
at the sides, the larger helical wheel 10, and is formed in one piece with the
stuffing box 6 and the main frame 2. The vertical valve-operating shaft 9
is mounted in a bearing cup 13 beneath the helical wheel, which cup 13 is
mounted in the bottom 14 of the casing 12. The mounting of the valve-
operating shaft 9 above the helical wheel 10 takes place in the cover 15 which
is attached to the casing 12 by means of screws and closes the same oil-tightly
above. In order to avoid any penetration of oil from the bearing cup, 16, its.
cover is also formed at the point 17 as a stuffing box. The inner chamber
enclosed by the casing 12, the bearing cup 4, and the lid 15 forms a vessel
closed on all sides. It may then be conveniently filled with oil so that the
helical wheels 3 and 10 constantly run in an oil bath and at the same time the
bearings of both the shafts receive a permanent and thorough lubrication.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondents, I declare that what I claim is:-
1. In four-stroke motors, an arrangement for conveying the movement from
the crank shaft to the valve-operating shaft by means of helical wheels, charac-
terised by the smaller helical wheel (3) being completely arranged inside a cylindrical
stuffing box bearing-cup (4) in such a way as to lie within a chamber closed on
all sides which is formed by the bearing cup (4), the stuffing box casing (6
and 12) and the casing cover (15), within which chamber the helical wheels (3
and 10) run in an oil bath, substantially as hereinbefore set forth.
2. A form of construction of crank shaft for the device herein before described,
characterised by a helical wheel (3) for conveying the movement to the valve-
operating shaft being formed in one piece with the crank shaft (1) and of such
dimensions that the bearing cup (4) of the crank shaft can be placed over the
said helical wheel (3), substantially as described.
Dated this 8th day of November 1898.