Improvements in Clamping Devices for Tightening Ball and Socket Joints and for other purposes.
Year: 1890

page_text: Date of Application, 1st Aug., 1890-Accepted, 25th Oct., 1890
[Communicated from abroad by HARVEY E. HOPKINS, of Chicago, Illinois, United
States of America, Manufacturer.]
Improvements in Clamping Devices for Tightening Ball and Socket
Joints and for other purposes.
I, HENRY HARRIS LAKE, of the firm of Haseltine Lake & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex, 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 :-
My invention relates to the connection of pitmen with the parts which they are
intended to drive and more particularly to these devices where the connection is made
by a ball-and-socket-joint, though it is not limited to this particular kind of connection,
but is applicable to any form of joint where there are parts to be clamped or held
together.
The invention consists in a clamping device mounted in a separate frame or holder,
which is applied to the branches of a pitman in such a way as to clamp them upon the
ball or other member of the connecting joint, this clamping device being in the shape
of a cam, actuated by a spring to hold it up to its work. The invention is especially
applicable to harvester pitmen, where they are connected to the knife-head by a ball
and socket-joint, and I have, in the drawings, shown the invention applied to such a
device, though I do not wish to be understood as limiting my improvement to this
particular application of it as here shown.
The usual inanner of making a ball and socket connection between the pitman and
knife-head in harvesting machines is to form the ball on the knife head and fork the
pitmen at its lower end, providing a part of the socket on each fork, so as to embrace
the ball between them. The ordinary manner of holding the sockets of the pitman up
against the ball has been to pass an ordinary bolt through the two forks of the pitman
near the knife-head and tighten the sockets upon the ball by a nut or some other like
device on one end of the bolt. With such a device the proper adjustment of the
sockets and ball depends upon the care and mechanical skill of those using the machine.
If the nut on the bolt is set up too tightly the over pressure of the socket upon the ball
will cause extra friction and a rapid wearing away of the parts and will also increase
the resistance to the driving power occasioned by the required movement of the pitman
and knife bar, thereby increasing the power required in the machine and the general
wear of the latter. But if the nut is not set up on the bolt sufficiently, the sockets
will be loose on the ball, thereby occasioning lost motion which will soon produce
lateral wear of both ball and sockets, thereby destroying the true circular joint; and
after such wear the nicest adjustment of the parts by even a skilled mechanic will not
produce a close joint and prevent lost motion. The injury thus effected is constantly
increased and frequently results in breaking either the pitman or knife-head or both
or, if there is no breaking, the ball and sockets will wear so rapidly as to become
perfectly useless before other parts of the machine show any perceptible wear.
In the application of my invention to harvesting machines the object is to obviate all
these difficulties and secure the clamping of the socketed arms upon the ball of the
knife-head with a uniform pressure automatically applied, whereby a nicely fitting
joint is constantly obtained, but without any undue friction.
I will proceed to describe in detail a practical mode of applying my invention to
harvester pitmen and will then point out more definitely in claims the special improve-
ments which I believe to be new and wish to protect by Letters Patent.
Figure 1, represents a perspective view of the lower end of a harvester pitman an 1
the inner end of a knife-bar with my invention applied.
Figure 2, a plan view of the same with the fastening device released.

page_text: Figure 3 a similar view with the rastening device in position and the top o
fastening holder.removed.
Figure 4, a detail plan of the fastening cam, detached.
Figure 5, a side elevation of the same.
Figure 6, a detail plan of the frame, detached and a portion of the top broken
away, and
Figure 7, a side elevation of the same.
Figure 1, of the drawings is on a scale by itself, all the other figures are upon the
same scale enlarged from the scale of Figure 1.
In the drawings, A represents the knife-head of the knife bar of a harvesting
machine and it is provided with a ball, a for the purpose of making the connection
with the pitman. Only a portion of the pitman, B, is shown, this being the lower
portion which is connected directly to the knife-head. This part of the pitman is
forked, that is, it consists of two bars beach of which terminates in a circular socket 1
adapted to fit on each side of the ball and clasp the latter between them as shown in
Figures 1, and 3, of the drawings. For the purpose of holding the arms of the
pitman-fork together, so as to clamp the ball in the socket with a substantially uniform
pressure, I provide a kind of clamping frame, C, which is substantially rectangular in
shape but is open at one end, as seen in Figure 7 of the drawings. The upper bar c,
of this frame is straight and has near the open end a short depending stud, e arranged
on one side of the bar. The lower bar c2, is bent upward near the open end, so that
the space between the two free ends of these bars is considerably less than in the body
of the frame. This lower bar also has a short projection c³ extending horizontally
from one side of the arm near its free end, this side being opposite to that on which
the stud before mentioned, is located on the upper bar. Both of these bars are perforated
at their free ends for the purpose of receiving a pivot pin, as will presently be
explained. The opening between the main portion of these bars is of a width corre-
sponding to the width of the socket bars on the pitman, so that the frame may be
slipped over the latter and will then embrace the bars, as shown in Figure 1, of the
drawings.
C
C3
A cam D, is mounted on this frame, being arranged in the opening between the
two free ends of the bars c c to which it is pivoted by means of a pivot bolt or pin E,
which passes through the apertures in the ends of these bars and a corresponding
aperture in the cam. The outer or cam edge d of this piece is curved eccentrically to
the pivot and is widened considerably, so as to make a broad bearing surface, as seen
in Figure 5, of the drawings. In the upper surface of this cam is a depression, d¹
circular in form and extending around the pivot opening and opening out at the edge
of the cam on one side, as seen at d², in Figure 4 of the drawings. The cam does not
fill the entire open space at the end of the frame in which it is mounted, and a spiral
spring, F, is arranged above the cam between it and the upper bar, c, the coil of the
spring being about the pivot bolt E. The outer end, f, of this spring is fastened to
the stud c¹ on the frame and the inner end f¹, lies in the depression in the upper side
of the cam, being carried across the latter and out at the opening 2, and is then
fastened to the cam by insertion in a notch d³, just outside of the said depression, as
seen in Figure 3, of the drawings. When the cam and spring are mounted in the
frame, as described, the force of the spring will act to turn the cam inward into the
main space of the frame, as seen in Figure 3, of the drawings. Now if the frame is
slipped upon the socket bars of the pitman and the latter are arranged to embrace the
ball, as shown in Figures 1, and 3, of the drawings, and the cam is left to the action
of the spring, it, the cam, will be turned inward by the force of the spring until it is
brought in contact with the inside bar of the pitman, against which it will be held up
firmly with a force depending upon the strength of the spring. The two socket bars
will, therefore, be clamped between this cam and the solid end of the frame, as seen in
Figures 1, and 3, of the drawings, and so the ball on the knife head will be embraced
firmly by the socket, pieces and will be held in this position by a practically constant
force due to the strength of the spring. In applying the frame to the pitman, it will
be convenient to turn the cam outward, so as to leave the entire open space of the

page_text: frame unobstructed; and also, if it is desired to detach the pitman from the knife-
head, it will be necessary to turn the cam outward so that the fork-arms may be
spread, as shown in Figure 2, of the drawings to permit them to be slipped off from
the ball. To facilitate the turning of the cam against the action of the spring, it is
provided with a short tail-piece d', by which a certain amount of leverage is obtained;
in
and furthermore, a short rod G, may be provided, which is inserted in a socket
the tail of the cam when it is desired to turn the latter, this rod constituting a short
lever by which the cam may be turned easily. In order to prevent the cam from
being turned too far, a short lug d³ depends from its under side and on the side or
edge of the cam opposite to the tail piece. When the cam is turned outward, as seen
in Figure 2, of the drawings, this lug will finally come in contact with the projec-
tion on the frame thereby stopping the further movement of the cam in this
direction, as is also seen in Figure 2 of the drawings; and the same lug will come
in contact with the rising bend of the lower bar c of the frame on the other side
of the latter, so that it will stop the turning of the cam in an inward direction,
when the frame is detached from the pitman.
With this device a practically constant force is applied to the fork arms of the
pitinan, so that the ball is clasped by the sockets with uniform pressure, and the
force being automatically applied under the constant action of a spring, all wear
of the joint is taken up immediately, however slight it may be. The degree of
force applied for the purpose of clamping the fork-arms upon the ball is easily
regulated so that the pressure of the cam will only be sufficient to hold the parts
in proper working position and, as the application of this pressure is not determined
by any adjustment effected by the attendant, it can never be increased, so as to
At the same
produce undue friction, or decreased so as to produce lost motion.
time the ball and the socket pieces are readily movable upon each other, so that
the joint is free working. The wear also of the joint will be uniform as the
It will
pressure is uniform whatever may be the relative position of the parts.
also be seen that this device provides for the ready and convenient attachment of the
pitman to the knife-head and also for its detachment therefrom, and, as the connection
and disconnection of these parts is a matter of quite frequent necessity in harvesting
machines, this result is quite an important one. There are no nuts or screw-bolts
to remove or to apply in connecting or disconnecting the parts. The connection
has already been described and in Figure 2, of the drawings, the disconnection is
fully illustrated; it is only necessary to turn the cam back in the position shown
in Figure 2, when the fork-arms of the pitman may be spread sufficiently to be
disengaged from the ball on the knife-head and then if desired the clamping frame
may be slipped off over the socketed ends of these arms.
not
In order to obtain these desirable results, it is obvious that the relation of the parts
should be determined with some care especially as to the pitch of the cam, and the
strength of the spring. I will, therefore, give an illustration which will serve some-
what as a guide for this purpose, though no arbitrary rule can be specified. The
length of the frame which is placed upon the pitman should be such as to permit the
cam to be turned inward, so that its point of contact with the fork arm of the pitman,
when in position as seen in Figure 3, of the drawings, is about the centre
of the cam face lengthwise. This of course, will depend upon the shape and
size of the pitman and also the shape and size of the cam, which are
arbitrary. The following dimensions however, I have found
will provide
devices which operate satisfactorily. Suppose the diameter of the ball on the knife-
head to be 1 inches and the fork-arms of the pitman running about parallel when
closed on the ball. The distance from the pivot of the cam to the point of contact with
the pitman should be about 13th inches. The length of the cam face is about three
inches and with this length of face I give about th of an inch take-up or pitch to
the cam; that is, the distance on the line 1-2 from the centre of motion to the head
or initial point of the cam is about th of an inch less than the distance on the
line 1-3 from the said centre to the tail end of the cam face. With these dimensions
the strength of the spring should be such as to give a resistance of about 5 pounds

page_text: placed 11 inches from the centre of the spring, when the latter is coiled to the extent
produced by the complete opening of the cam-that is, when the latter is brought into
the position shown in Figure 2 of the drawings. These relative dimensions of the
parts specified I find give entirely satisfactory results, but I give them simply for
illustration and am not to be understood as restricting my invention to these limitations
in construction. The dimensions may be changed in different locations and the pitch
or take-up of the cam may be increased or diminished; if increased without other
changes, the strength of the spring should be increased, and if diminished the spring
should be weakened to correspond.
Furthermore, as already stated, I do not wish to be understood as limiting my
invention to its application herein shown and described to harvester pitman, or to
pitmen generally; but I claim the invention wherever it may be applied for the
purpose of clamping two movable pieces together without radical change in construc-
tion. It may be applied to the two parts of journal boxes and any other like position
with satisfactory results; hence I do not wish to be understood either as limiting my
invention to a special application to harvester or other pitmen, or to the special con-
struction and arrangement of the parts herein shown and described when applied to
pitmen or elsewhere. Springs of different construction may be applied and a different
piece substituted for the cam, provided this piece always has an inclined or wedging
face to provide for take-up; and the holder for the devices and the mounting of them
therein may be varied from that here shown.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed as communicated to me by
my foreign correspondent, I declare that what 1 claim is :-
First. Two bearing surfaces adapted to receive and clasp between them a ball of
other like journal, in combination with a holding frame applied to and surrounding
the said bearing surfaces, a cam mounted in said frame and arranged to clamp the said
bearings together, and a spring arranged to actuate the said cam automatically,
substantially as and for the purposes specified.
Second. The knife-head A, provided with a ball a, in combination with the forking
arms b, of the pitman provided with sockets adapted to receive the said ball, the
clamping frame C, adapted to receive the arms of the pitman, the cam D, pivoted on
said frame, and the actuating spring F, arranged to turn the cam inward against one
arm of the pitman, substantially as and for the purposes specified.
Third. The fork-arm b, of the pitman, adapted to receive and clamp a ball between
them, in combination with the clamping frame C, adapted to be slipped upon said arms,
the cam D, pivoted between the open ends of the frame, and the actuating spring F,
coiled around the pivot pin of the cam and connected at one end to the latter end at
the other to the frame, substantially as and for the purposes specified.
Fourth. The fork-arm 6 of the pitman, in combination with the clamping frame C
provided with the lug or projection c³, the cam D pivoted on said frame and
provided with the lug and the actuating spring F, substantially as and for the
purposes specified.
Fifth. The fork arms b of the pitman, in combination with the clamping frame C,
the cam D, pivoted in said frame the actuating spring F, and the detachable lever or
handle G, substantially as and for the purposes specified.
HASELTINE, LAKE &.Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.