Improvements in Cramps applicable as Lifting Jacks.
Year: 1891

page_text: COMPLETE SPECIFICATION.
Improvements in Cramps applicable as Lifting Jacks.
I, JOHN JAMES BILLET LILLINGTON of White Horse Road, Blackburn,
near Melbourne, in the Colony of Victoria, Australia, Builder, 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 of an improved clamp has for its object specially the clamping
or forcing tightly together of boards used for floorings, ceilings, and linings in
buildings, these boards being usually formed with tongues and grooves thus
rendering them difficult of being tightly jointed by the present means in use
and in general the clamp can be utilised for all classes of joinery work, and
it is also usable with good results as a lever for lifting or forcing, as for
instance, where joists, beams and other heavy timbers used in buildings are
required to be moved or placed in position.
The clamp consists of a suitably designed base frame of a heart shape or
form and provided with lugs or equivalent projections on which are mounted
small transverse spindles for carrying the cogged lever and ratchet pawl respec-
tively, the latter being for the purpose of retaining the position and pressure
obtained by the former.
Between these lugs and near their base is a horizontal plunger on which is a
rack and ratchet for engaging with the cogged lever and pawl respectively.
On the end of this plunger is arranged a serrated face plate for the purpose of
gripping the board desired to be clamped.
Upon this base frame are vertical bosses in which are journalled spindles the
latter carrying at their lower ends the eccentric cam shaped grippers. These
grippers have milled or serrated faces in order to prevent the clamp when at
work from slipping on the joist or stud of the building. To the upper part of
the said spindles, handles are attached for operating the grippers.
The cogged radial lever is fitted with a box rod, for convenience made of a
bent form, said rod is detachable, and can be reversed in position if desired.
The teeth in the circular portion of the lever are arranged to neatly engage
with the rack on the aforesaid horizontal plunger.
Reference may now be made to the accompanying drawings in which
Figs. 1 and 2 are side and front views of the clamp respectively, whilst
Fig. 3 is a plan of the same.
Figs. 4 and 5 show plan and elevation of the base plate and gripping action
of a duplicate auxiliary part to act as a stop for general joinery purposes.
The dotted lines in these figures represent the joist and flooring, or studs and
lining boards as the case may be. In these figures A is the frame or base
having cheeks A' thereon for carrying the spindles and acting as guides for the
plunger before referred to, also are formed thereon the upper and lower
bosses A' and A³ respectively, for holding the spindles of the cam grippers.
B is a horizontal plunger on which is formed the rack B¹ ratchet B₁ and
face B the latter is roughened or serrated to more effectively grip the board
operated upon.
C is a spindle working in said cheeks A' on which is pivotted the lever C¹
provided with teeth C³ for engaging with rack B on plunger B.
D is another spindle also working in the cheeks A¹ from which depends a
pawl or dog D' for engaging with the ratchet B³. The object of pawl D' is
to retain the pressure that has been obtained by means of the cogged lever C
upon the board, and thus allowing the plunger B to move forward but not back-
ward except when the latter is desired, in which case the pawl can be lifted

page_text: and thrown out of operation. The bosses A' and A³ carry the vertical spindles E
of the eccentric cam grippers E¹ the former being provided with nuts E' for
vertical adjustment, and handles E' for opening and closing the grippers to suit
the width of joist or other anchorage.
The faces of these grippers E are serrated or milled at an angle diagonal
thereto so as to give them a more effectual hold and prevent their moving
upwards.
F is a detachable bent handle having a hollow head or box F¹.
G is the flooring or other board under treatment, H being the joist or anchor.
The mode of using this invention is as follows:-The clamp resting upon its
frame A is so placed upon say the joist H that the latter comes between the
eccentric grippers E'.
The
The face B of the plunger B is now placed immediately against the say flooring
board G to be clamped, and the grippers E¹ are tightened by means of their
handles E the eccentric formation of the grippers resulting in a sudden tightening
hold, which hold is increased and intensified during the cramping process.
horizontal plunger B is now operated by handle F which can be of any length and
cogged lever C in the usual manner with the result that a strain or pressure is
obtained against the board G to any required degree; the pawl D' retaining such
strain upon the board G until the latter is permanently secured by nails or
otherwise.
When this is effected, the grippers E¹ are released by reverse motion of
handles E the pawl D' is lifted and plunger rack B is brought back to position
for work; the tool is then slid along joist Hito take up a new position for operations
on another board.
When heavy objects, such as joists beams and the like are required to be lifted
or placed firmly in position the apparatus is usable as a lever by being cramped
to some existing beam or joist and the handle worked as 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-
1st. In tools for clamping timber, a plunger such as B working in guides and
having a rack formed on it, said rack being operated by a cog ended lever such
as C¹ to which motion is imparted by a handle such as F substantially as and for the
purposes herein explained and described, and illustrated in the accompanying
drawings.
2nd. In tools for clamping timber a plunger as B with a ratchet formed thereon,
with which a pawl engages and retains any strain imposed on the plunger by the
operator substantially as hereinbefore set forth.
3rd. In tools for clamping timber the combination of the spindles E, cams E¹,
bosses A and A', with the handles E³, for adjusting tension, substantially as
explained and as illustrated.
4th. In tools for clamping timber the general combination, construction and
arrangement of parts consisting of a frame as A, with its parts A¹, A', and A', a
plunger as B, with its parts B1, B2, and B³, a pivotted cogged lever as C', with its
parts C, and C, a pawl as D', and its spindle D, the eccentric grippers as E', with
their parts E and E³, substantially as and for the purposes herein set forth explained
and illustrated.
Dated this 21st day of October 1891
THOMAS PRESCOTT,
53, Arcade Chambers, St. Mary's Gate, Manchester,
Agent for Applicant.