Improvements in Crank Mechanism.
Year: 1897

page_text: Date of Application, 8th Mar., 1897
Complete Specification Left, 8th Dec., 1897-Accepted, 8th Mar., 1898
.
PROVISIONAL SPECIFICATION.
Improvements in Crank Mechanism.
I, ROBERT GRISSON, of 16a, Ellernthorsbrücke, Hamburg, in the Empire of
Germany, Engineer, do hereby declare the nature of this invention to be as
follows:-
•
This invention relates to a crank mechanism with a driving shaft supported
eccentrically to the crank bearing and connected with the crank by a sliding lever.
The arrangement of the new crank mechanism is as follows:-
A crank is supported so as to be capable of turning about a bearing, say by
means of a ring, and the shaft to be turned passes eccentrically through the crank
bearing. The shaft carries an arm or lever which is connected with the crank
through the medium of a sliding block adapted to move in a slot in the crank.
By this crank mechanism a force acting at the free end of the crank is designed
to be utilized as advantageously as practicable. When the mechanism is for
instance employed for a hand winch whose drum is arranged upon the shaft the
workman, in the usual position of the drum relatively to him, can physiologically
exert the greater power during the movement of the crank through its upper
path, and the smaller power during the movement of the crank through its lower
path. By the crank mechanism it is intended that this power shall be fully
utilized, which is in fact the case, for during the passage of the crank through its
upper path, in contradistinction to the passage of the crank through its lower path,
there is the shorter lever arm moving at a smaller angular velocity. Accordingly
the workman, with a slower movement of the crank, has here to exert his full
power, and he may exert less power during the passage of the crank through the
lower path with a quicker movement of the crank. These working conditions
ensure a uniform turning movement of the driving shaft or axle.
The arrangement herein before set forth may also be on two sides with two cranks
which help each other over their dead points.
Dotod this 8th day of March 1897
Improvements in Crank Mechanism.
I, ROBERT GRISSON, of 16A, Ellernthorsbrücke, Hamburg, in the Empire of
Germany, 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: —
This invention relates to a crank mechanism with a driving shaft supported
eccentrically to the crank bearing and connected with the crank by a sliding lever.

page_text: In order that my invention may be better understood by those skilled in the art
to which it appertains, I will proceed to describe the same in detail and for that
purpose will refer to the accompanying drawing, wherein
Figure 1 is an elevation of the improved crank mechanism;
Figure 2 is a transverse section on the line 1, 2 of Fig. 1; and
Figure 3 is an elevation showing the crank mechanism in the opposite working
position.
Similar letters refer to similar parts throughout the several views.
A crank a is supported so as to be capable of turning about a bearing 6, by
means of a ring a, and the shaft c to be turned passes eccentrically through the
crank bearing b. The shaft c carries an arm or lever d which is connected with
the crank a through the medium of a sliding block d' adapted to move in a slot a³
in the crank a so that the latter and the lever d are practically in one plane.
By this crank mechanism a force acting at the free end of the crank i- designed
to be utilized as advantageously as practicable. When the mechan .n is for
instance employed for a hand winch whose drum is arranged upon the shaft c the
workman, in the usual position of the drum relatively to him, can physiologically
exert the greatest power during the movement of the crank through its upper path,
and the smallest power during the movement of the crank through its lower path.
By the improved crank mechanism it is intended that this power shall be fully
utilized, which is in fact the case, for during the passage of the crank through its
upper path, in contradistinction to the passage of the crank through its lower path,
the shorter lever arm moves at a smaller angular velocity. Accordingly the work-
man, with a slower movement of the lever d, has here to exert his full power, and
he may exert less power during the passage of the crank through the lower path
with a quicker movement of the lever d. These working conditions ensure a uni-
form turning movement of the driving shaft or axle.
The arrangement herein before set forth may also be on two sides with two cranks
which assist each other over their dead points.
The slot as in the crank a may be closed or shut up, when required, by suitable
covers or plates e of any convenient material as for instance celluloid as indicated
in Figure 3, so that the lever d and its sliding block work in a holly closed
box. This box, moreover, may be used for lubricating purposes by filling it up
with a suitable lubricant or oil. In order that the lubricant may pass from the
outer side of the sliding block to the inner for lubricating the bearing and shaft
suitable grooves or perforations may be provided in the said sliding block.
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. A crank mechanism having a crank arm rotating eccentrically to the shaft
to be driven and connected with the latter by means of a lever and a suitable guide
block sliding in a slot of the said crank arm, substantially as and for the purpose
Bet forth.
2. In a crank mechanism the combination of a shaft (c) lodged eccentrically in
a bearing (b), a crank arm (a a¹) adapted to rotate on the said bearing eccentrically 4
to the said shaft, a lever (d) firmly attached to the shaft, and a guide block (d¹)
connected with the free end of the lever (d) and sliding with the latter in a slot (a³)
of the crank arm, substantially as and for the purpose specified.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.