Improved Apparatus for Effecting Locked Step-by-step Rotary Motion from a Reciprocating Motion, especially applicable to Counting Trains.
Year: 1899

page_text: Date of Application, 11th Dec., 1899 -Accepted, 12th May, 1900
COMPLETE SPECIFICATION.
Improved Apparatus for Effecting Locked Step-by-step Rotary Motion
from a Reciprocating Motion, especially applicable to Counting
Trains.
We, EVERSHED AND VIGNOLES, LIMITED, of Woodfield Works, Harrow Road,
London, W., Electrical Engineers, and SYDNEY EVERSHED, of the same address,
Electrical 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 apparatus for the conversion of a reciprocating move-
ment into a step-by step positive rotation of an axle, and is designed to utilize
a reciprocating movement of variable amount, within a certain minimum and
maximum, to give a perfectly positive and locked step-by-step rotary movement
of an axle in one direction, only one step feed being effected for each reciproca-
tion whatever its length within certain minimum and maximum limits, and the
rotary step wheel being always held and locked against over-running or reverse
movement when not feeding forward.
It is obvious that such an apparatus has a wide field of application, either as
a first movement to a counting train, indicating the number of reciprocations, or
in any instrument in which a reciprocating movement is to be converted into a
positive step-by-step motion.
And in order that our invention may be the better understood we now pro-
ceed to describe the same reference being had to the drawings hereto annexed
and the letters and figures marked thereon.
The example we show in the drawings annexed is a perfected form of appa-
ratus to fulfil the purposes above recited, but it is obvious that many modified
but equivalent parts might be combined to effect the required purpose without
departure from the essence of this invention.
Figure is a plan of our apparatus with the reciprocating movement at one
extreme range of its position as regards effective operation.
Figure 2 is a plan of the same with the reciprocating movement at the other
extreme range of its position as regards effective operation.
Figure 3 is an elevation of the same.
Figure 4 is a part plan with a modification of pin detents in place of a spring
control.
A, B shows the line of reciprocating movement across the apparatus, which
may be communicated by a rod or bar, or in other convenient manner to the
pin C carried on an arm D, pivotted upon the axle of the rotary step-by-step
wheel E.
The latter wheel E is provided with a crown flange having uniformly spaced
gaps F, within which the pawl teeth G of the pallets H and J alternately engage.
The pallet H is pivotted upon the pin or axis K, the tail of the pallet ter-
minating with a headed pin L, engaging in a curved slot M of the other pallet
or arm J. This latter pallet or arm J is pivotted on the same pin C on the

page_text: radial arm D at which the reciprocating movement is applied. The tail of this
pallet or arm J is connected to a control spring N in the arrangement shown in
Figures 1, 2 and 3.
The essence of the arrangement is the inter connection between the fixed
rocking pallet H, and the travelling pallet J, by the pin L and the curved slot M,
so that when the tooth of one pallet is engaged in the gaps of the wheel E,
which may be a crown wheel as shown or a toothed wheel of any kind, the other
other must be disengaged, and vice versa; and further that the control spring N
or equivalent pins or detents P (Figure 4) shall effect the simultaneous engage-
ment and disengagement respectively of the pawl teeth G from the crown
wheel E, at a certain angular movement of the arm D, under the impulse
of the reciprocating motion from A to B and vice versa.
Until this simultaneous movement of engagement and disengagement of the
teeth G, respectively, at the ends of a certain angular movement of D, the
engaged tooth G remains a locking tooth, the disengaged tooth pressing upon and
sliding over the metal face of the crown wheel E, without power to disengage
the engaged tooth until it arrives opposite to a gap F. At this point, under
the pressure of the control spring N, or under the impact of the tail of the
pallet or arm against pins or detents P (Figure 4), the disengaged tooth enters
into the gap F and simultaneously the formerly engaged tooth flies out, ready
for re-engagement on the return stroke of the reciprocating movement into the
next gap F, and so on.
After the said engagement of a tooth G, has been effected as in Figures 1
and 2, it is obvious that the reciprocating movement can still be continued,
carrying the crown wheel with it, within the limits of the length of the slot M,
without interfering with the regular step-by-step rotation of E, for each recip-
rocation of the pin C.
Thus considerable variation in the length of the reciprocating motion A to B
can be permitted, without affecting the positive step-by-step rotating record of
the wheel E for each reciprocation.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:
--
Ist. An apparatus for the conversion of a reciprocating motion into a locked
and positive step-by-step rotary motion, consisting of, in combination, a toothed
wheel on a fixed axis, and two rocking pallets, each having a tooth adapted to
engage in the spaces between the teeth of the said wheel, one pallet rocking on
a fixed pivot, and the other on a pivot travelling with the reciprocating motion
such pallets engaging with one another by a pin on the one sliding in a slot
upon the other of greater -length than is necessary for the operative travel; the
travelling pallet being controlled by a spring or detents, adapted to operate said
pallet on either side of the centre of the reciprocating movement, to effect alter-
native engagement and disengagement of the teeth of the said pallets, substan-
tially as and for the purposes described.
2nd. In combination, the parts of an apparatus for converting reciprocating
motion into positive and locked step-by-step rotary motion, substantially as
herein above described and illustrated in the drawings annexed hereto.
Dated this 11th day of December 1899
FELL & JAMES,
Agents for the Applicants.