An Improved Lifting Jack.
Year: 1889

page_text: An Improved Lifting Jack.
1, ANDREW WARREN of 707 North Second Street, St. Louis in the State of
Missouri United States of America 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 consists of an improved lifting jack and relates specially, first to an
improved form of grip and secondly to lowering means, while at the same time I
have generally improved the construction of the jack to better effect the action of
the lifting devices. The invention described in the Specification to Patent No. 7857
dated May 29th 1888 communicated by me to C. A. Day relates to jacks embodying
the same general principle of the jack shown in this application namely a lifting bar
vertically movable within a standard with a grip contained in a chamber in the
standard head and a movable clutch box also containing a grip with an operating
lever for giving a vertically reciprocating movemem to the clutch box in order to
raise the lifting bar with its load. This Specification also shows a lifting bar having
a tapered hearing face and in my present Invention I make use of the main features
as enumerated above of the said Patent, though I do not limit myself to the
particular form of grip shown therein nor to the tapered lifting bar.
In the accompanying drawings
:-
Figure 1 represents a vertical longitudinal section of the standard and bar and the
clutch box, and my invention as applied to one side of the lifting bar.
Figure 2 is a horizontal section on line x-x of Figure 1.
Figure 3 is a sectional view of a modification.
T
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page_text: :-
a sectional view of the standard and lifting bar with modified means
for releasing the grip in the standard and throwing aside the lowering lug and
Figure 6 is a detail sectional view through the clutch box showing the cam shaft as
adapted to work directly against the face of the lifting bar.
In these drawings the standard is shown at A and the lifting bar at B and this
lifting bar may be tapered as shown in figure 1 and as represented in the Specification
above referred to, or it may be a bar with parallel sides as ordinarily used.
While I have shown my gripping devices as applied to one side of the jack it will
be understood that they may be duplicated where a more secure grip is required in
the lifting of heavy loads.
The standard A has a recess in its upper end in line with the channel through
which the lifting bar passes and this recess may have a backing plate to take up
the wear, and the lifting har, or that face which is in contact with the gripping
devices may also be protected by a wearing plate as in the Specification referred to.
Within the recess in the standard which has an inclined rear wall is a grip a which
may be a roller as shown in figure 1 a segment as in figure 4, a wedge as in figure 5
or any of the forms of grips shown in my aforesaid Specification or any other which
may be suitable for the purpose-This grip a it will be understood serves to hold the
bar from slipping when it is released from the grip within the clutch box and while
the operator is taking a fresh hold through the lifting lever. The clutch box is
shown at C and encircles the lifting bar, having a chamber in which is held the
clutch block b which is in contact with the face of the lifting bar and serves to grip
it under the action of a cam shaft c, operated through a connection with the lever d,
which is fulcrumed on the upper end of the standard. This connection consists of
short arms 1. 1. extending from the cam shaft and connected with the lower end of
the lever by links 2, 2. Any suitable lever may be used and any connection between
the lever and the am shaft adapted to operate the same may be substituted for the
connection shown.
The clutch block or grip b, is shown as fitting snugly in the chamber within the
clutch box but this is not essential though I prefer it. By the movement of the
lever the cam shaft is turned so that its cam face forces inwardly the clutch block
against the face of the lifting bar and thus forms a grip which enables the box to
lift the bar under the continued action of the lever, but it will be understood that
instead of the clutch box or any equivalent thereof the cam shaft may be arranged
a little closer to the face of the lifting bar and thereby act directly thereupon without
the interposition of anything whatever as shown in figure 6. For the sake of
durability, however and to take up the wear I prefer to interpose either the clutch
block or some equivalent thereof.
Ate in Figure 1 I have shown a lowering lug pivoted at its inner corner to the
lower part of the clutch box, the pivot passing through the side nearest to the face of
the lifting block, so that in its normal position the lug will swing in by force of
gravity close to the face of the lifting bar and in this position as the bar is held by
the grip in the standard the clutch box may be lowered to take a fresh hold upon the
lifting bar and the lug will pass through an opening in the top of the standard fitted
to receive it which will thus allow the bottom of the clutch box to come in contact
with and to rest upon the top of the standard.
In Figure 3 I have shown a modified form of the lug e and in this figure instead of
supporting it by pivoted connection with the frame of the clutch box I slot the lower
part of the box and pivot the lug directly to the clutch block b, so that as the said
block moves in or out under the action of the lever or the lifting bar the said lug will
maintain the same relative position to the face of the bar. This is specially desirable
when the tapered lifting bar is used.
In order to effect the operation of lowering either instaneously or gradually as
may be required I provide a foot lever for releasing the clutch in the standard and at
the same time to throw out the luge so that as the clutch box lowers, the said lug will
he out of line with the opening in the top of the standard and will thus support the

page_text: clutch box by its engagement with the standard. This consists of a foot lever /
pivoted at 3 with a rod connecting with its inner end as at g, this rod extending up
between the face of the lifting bar and the channeled face of the standard. In its
normal position the upper end of this rod rests within the groove in the centre of the
gripping face within the recess in its standard so that it does not interfere with the
action of the grip in said recess under normal conditions. This rod is provided with
a stud 4 projecting from one side which, when the rod is in its lowest position simply
remains inactive at the bottom of the recess, but when it is desired to release the lifting
bar from the action of this grip the operator simply places his foot upon the treadle
depressing the same, which lifts the rod g and through the stud 4 raises the grip out
of contact with the bar. At the same time the inclined end of the rod strikes the inner
edge of the lug e and throws it to one side so that as before stated this lug rests upon
the head of, the standard and supports the clutch box thereupon. In this position as
the grip in the standard is out of engagement with the lifting bar the bar may be
lowered gradually by a slight up and down movement of the operating lever or by
throwing the lever into a position to release the lifting bar from the grip of the clutch
box the said bar will fall at one movement to its lowest position.
So long as the upper end of the rod g is between the lug e and the face of the
lifting bar the said fug will be kept in contact with the standard, but as soon as the
rod is lowered the lug will slip from its position upon the standard by gravity and by
rounding either the corner of the lug or that part of the standard upon which it rests
it is thus allowed to slip off easily and to fall into the opening in the top of the standard
which thus brings the clutch box into its normal position.
In Figure 4 I have shown a modified form of grip adapted to be used in the
standard, this being a segment pivoted within the recess in the standard head and
having a curved gripping face adapted for contact with the lifting bar as shown. The
curved gripping face is provided with a central groove through which the rod y passes
as before described in the form of grip shown in figure 1. In figure 5 I have
represented the grip in the standard head in the form of a wedge and the rod g which
connects with the treadle f is connected to the lower end of said wedge and in order
to operate the lowering lug in the upward movement of the grip a, in this figure 1
provide an upward extension a' which tapers to a point so that as the grip is moved
upwardly the extension a' throws the lowering lug outwardly in the manner and for
the purposes before described.
Having now particularly described and ascertained the nature of my said inven
tion and in what manner the same is to be performed I declare that what
I claim is
1. In a lifting jack, a standard, a lifting bar, a holding grip in the standard, a clutch
box, a cam shaft within the clutch box, an operative lever and a positive connection
between said lever and the cam shaft for operating the same, to grip and raise the
lifting bar, substantially as described.
2. In a lifting jack, a standard, a lifting bar, a clutch box, a cam shaft within said
clutch box, an operating lever pivoted on the standard, arms 1, 1, secured to the cam
shaft and links connecting said arms with the lower end of the lever substantially as
described.
3. In a lifting jack, a standard, a lifting bar, a clutch box, a cam shaft, an interposed
clutch block between said shaft and the face of the lifting bar, an operating lever and
connections between said lever and the cam shaft substantially as described.
4. In a lifting jack, a standard, a lifting bar, a grip within the standard, a clutch
box carrying a grip, a lever and connections for operating said grip, a lowering lug
carried by the clutch box, the standard having an opening in line with the normal
position of the lowering lug and means for releasing the grip in the standard and
throwing aside the lowering lug substantially as described.
5. In combination, a standard, a lifting bar, a grip within the standard, a clutch box,
a grip within the same and an operating lever, a lowering lug carried by said clutch
box and pivoted at one side, the standard having an opening line with the lowering

page_text: lug, a foot lever at the base of the standard and connections therefrom for releasing
the grip in the standard and for throwing aside the lowering lug substantially as
described.
6. In combination a standard, a lifting bar, a grip in the standard, a clutch box, a
clutch block within the same, an operating lever, a lowering lug carried by said clutoh
block and pivoted at one corner, the standard having an opening in the top thereof
in line with the normal position of the lowering lug, a rod for releasing the grip
in the standard and for throwing aside the lowering lug substantially as described.
Dated the 30th day of April 1889.
PHILIP M. JUSTICE,
55 and 56, Chancery Lane, London,
Applicant's Agent.