Improvements in Detent Valve Gear for Steam Engines.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Detent Valve Gear for Steam Engines.
I, MAX FRIEDRichi Gutermuth, of Darmstadt, Germany, Professor at the Grand
Ducal Technical High School, do hereby declare the nature of this invention to
be as follows:
This invention relates to an improved construction of detent valve gear for
steam engines worked by lift valves, whereby such mechanism is rendered of
very simple construction and operation, while at the same time the falling parts
thereof are rendered as light as possible, in order that such mechanism may be
rendered applicable with advantage to quick running engines.
The gear for working the lift valves consists on the one hand of an excentric
or cam whose rod oscillates upon a fulerum so arranged either above or below
the excentric rod that the free end of the latter has a curvilinear motion imparted
to it, suitable for effecting the raising of the inlet valve gear. This curve cau
he of elliptic form as shewn at Fig. 1 of the accompanying drawings if the valve
can be raised with a quick motion but it is preferable to give the curve such a
form as indicated at Fig. 2 that a gradual raising of the valve gear is effected
thereby.
The lever that effects the raising of the valve acts upon the valve spindle
through an intermediate connecting piece as shewn in which it can be shifted
longitudinally by means of the moveable fulcrum lever S. The excentric rod
lifts the free end of the lever h, thus raising the valve, the duration of the opening
of the latter being dependent upon the position of the lever h relatively to the
end of the excentric rod.
If the lever h be moved backward to such an extent that its extremity. does not
lie within the path of the said lifting curve the valve will not be opened at all
and consequently the engine will run without steam, while by shifting the lever
more or less forward, the cut off may be made to give a filling equal to 70 per cent.
or more of the stroke.
This improved detent valve gear has the following essential advantages.
It has only a small number of pivots and joints; the free falling parts are
reduced to a minimum weight; the pressure between the contact surfaces of the
moving parts is only small and consequently their wear is correspondingly
reduced, and the motion is a quiet one and there is no reaction upon the governor
which acts upon the fulcrum lever S of the lever h.
In order to avoid any detrimental action of the reversing motion of the engine
upon the valve gear, the lever h Fig. 2 is made forked, and is made to bear
only in the upward direction upon the valve spindle, so that in the event of the
engine running backwards, the excentric rod in coming in contact with the
lever h on its downward motion, can carry it down with it. A spring acting on
the lever as shewn causes it to be brought back to its contact with the valve
spindle after such depression; or the lever may preferably be connected to a

page_text: suitable known cataract device for the purpose of maintaining the proper contact
between the lever and valve spindle..
With the arrangement of the lever has at Fig. 1 a simple device may be com-
bined for forcibly closing the admission valve; for this purpose a two-armed
lever Fig. 3 is provided, whose arm ¹ is raised by the end of the excentric
rod on its return motion, thereby causing the arm to press downwards upon
the end of the lever h, and thus to forcibly close the valve if from any cause it
should stick in the open position.
Dated this 20th day of February 1899.
Improvements in Detent Valve Gear for Steam Engines.
I, MAX FRIEDRICH GUTERMUTH, of Darmstadt, Germany, Professor at the Grand
Ducal Technical High School, 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 gear for working the lift valves consists on the one hand of an eccentric
steam engines worked by lift valves, whereby such mechanism is rendered of
very simple construction and operation, while at the same time the falling parts
thereof are rendered as light as possible, in order that such mechanism may be
rendered applicable with advantage to quick running engines.
The gear for working the lift valves consists on the one hand of an eccentric
or cam whose rod oscillates upon a fulcrum so arranged either above or below
the excentric rod that the free end of the latter has a curvilinear motion imparted
to it, suitable for effecting the raising of the inlet valve gear. This curve can
be of elliptic form as shown at Fig. 1 of the drawings accompanying my Pro-
visional Specification, if the valve can be raised with a quick motion, but it is
preferable to give the curve such a form as indicated at Fig. 2 that a gradual
raising of the valve gear is effected thereby.
The lever that effects the raising of the valve acts upon the valve spindle
through an intermediate connecting piece as shewn in which it can be shifted
longitudinally by means of the movable fulcrum lever S. The excentric rod
lifts the free end of the lever h, thus raising the valve, the duration of the opening
of the latter being dependent upon the position of the lever h relatively to the
end of the excentric rod.
If the lever be moved backward to such an extent that its extremity does not
lie. within the path of the said lifting curve the valve will not be opened at all
and consequently the engine will run without steam, while by shifting the lever
more or less forward, the cut off may be made to give a filling equal to 70 per cent.
or more of the stroke.
This improved detent valve gear has the following essential advantages.
It has only a small number of pivots and joints: the free falling parts are
reduced to a minimum weight: the pressure between the contact surfaces of the
moving parts is only small and consequently their wear is correspondingly
reduced, and the motion is a quiet one and there is no reaction upon the governor
which acts upon the fulcrum lever S of the lever h.
In order to avoid any detrimental action of the reversing motion of the engine
upon the valve gear, the lever h, Fig. 2, is made forked, and is made to bear
only in the upward direction upon the valve spindle, so that in the event of the

page_text: engine running backwards, the excentric rod in coming in contact with the
lever on its downward motion, can carry it down with it. A spring acting on
the lever as shewn causes it to be brought back to its contact with the valve
spindle after such depression; or the lever may preferably be connected to a
suitable known cataract device for the purpose of maintaining the proper contact
between the lever and valve spindle.
With the arrangement of the lever as at Fig. 1 a simple device may be com-
bined for forcibly closing the admission valve; for this purpose a two-armed
lever Fig. 3 is provided, whose arm is raised by the end of the excentric
rod on its return motion, thereby causing the arm 2 to press downwards upon
the end of the lever h, and thus to forcibly close the valve if from any cause it
should stick in the open position.
The new gear may obviously be modified in various ways without changing
its mode of operation and the resulting advantages thereby, especially the
independence of the regulator.
The lateral thrust exerted by the excentric rod on the lever is resisted by the
friction in the eye of the valve spindle and does not act on the fulcrum of the
lever h.
This fulcrum is shewn in the drawings arranged at the upper end of a standing
lever S, it might as well be arranged at the lower end of a hanging lever, or in a
sliding piece guided in a curvilinear or straight slot.
Having thus particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim in
respect of detent valve gear for steam engines and the like is:-
1. The combination of the vertical valve spindle with a lever slidably connected
between its ends to the said spindle, means of imparting motion to one end of the
lever from an excentric rod and means of shifting the said lever lengthwise by
the action of a regulator, substantially as described.
2. The combination of the vertical valve spindle with a lever slidably connected
between its ends to the said spindle, means of imparting motion to one end of the
lever from an excentric rod and a movable fulerum lever jointed to the other end
of the said lever and controlled by a regulator, substantially as described.
3. The combination of the vertical valve spindle with a lever slidably connected
between its ends to the said spindle, means of imparting motion to one end of the
lever from an excentric rod and a movable fulcrum lever jointed to the other end
of the said lever and controlled by a regulator and a two-armed spring lever h¹²,
substantially as described.
Datad this 07th day of Catalin 1900