Improvements in Clamping Apparatus for Laying Floors and for other purposes.
Year: 1893

page_text: Date of Application, 8th May, 1893
Complete Specification Left; 8th Feb., 1894-Accepted, 10th Mar., 1894
PROVISIONAL SPECIFICATION.
Improvements in Clamping Apparatus for Laying Floors and for
other purposes.
I, ROBERT ALLEN, of 2 Oakley Villas, Caversham Road, Reading in the
County of Berks, Engineer, do hereby declare the nature of this invention to be as
follows
This invention for improvements in clamping apparatus for laying floors and for
other purposes, has for its object to provide an efficient apparatus of simple con-
struction which shall not be liable to derangement, and which can be easily and
expeditiously manipulated when in use.
In laying floor boards as ordinarily practiced each fresh board added to the
floor is pressed and held tightly against the next until secured to the joists by a
chisel or other similar tool driven into the said joist.
Now one arrangement of clamping apparatus constructed accordingly to this
invention comprises a frame the underpart of which forms a saddle which embraces
the upper part of the joist. To the depending sides of this saddle are hinged, on
vertical axes, levers provided with serrated or rat trap jaws which automatically
grip the joist, by means of suitable springs, so as to secure it firmly in position, and
prevent the apparatus from sliding along the joist.
Mounted on the upper part of the frame is a sliding crosshead working in
suitable guides thereon, and formed on its upper side with a toothed rack in which
engages one end of a hand lever pivotted to a link whose remote end is pivotted to
the frame. By oscillating this hand lever the crosshead can be caused to slide
forward one tooth at a time and press against the board to be secured. A spring
connected to the crosshead automatically forces it back into its initial position,
ready for a fresh operation, when released. The crosshead is automatically held
in any required position by means of a cam or nipping lever, rack and pawl or
other suitable holding device.
By suitably modifying the base of the frame, this apparatus can be used for
laying parquet flooring, as a joiners bench clamp, or for other like purposes.
In a modified arrangement of clamp the operating hand lever above described is
replaced by a toggle lever or link arrangement one link acting as a pawl and
engaging with the toothed rack of the sliding crosshead: or one link is pivotted to
the crosshead while the other acts as a pawl and engages with a rack on the base
plate of the clamp.
In a further modification I dispense with the above described racks and pawis
and pivot the ends of the toggle links to the sliding crosshead and base plate
respectively and operate them by means of a screw.
Dated this 8th day of May 1803
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.

page_text: Improvements in Clamping Apparatus for Laying Floors and for
other purposes.
I ROBERT ALLEN, of 2 Oakley Villas, Caversham Road, Reading in the
County of Berks, 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 for improvements in clamping apparatus for laying floors and for
other purposes has for its object to provide an efficient apparatus of simple
construction which shall not be liable to derangement, and which can be easily
and expeditiously manipulated when in use.
In laying floor boards as ordinarily practiced each fresh board added to the floor
is pressed and held tightly against the next until secured to the joists by a chisel
or other similar tool driven into the said joist, or by cramps.
Now one arrangement of clamping apparatus constructed according to this
invention comprises a frame the under part of which forms a saddle which embraces
the upper part of the joist. To the depending sides of this saddle are hinged on
vertical axes levers provided with serrated or rat trap jaws which automatically
grip the joist, by means of suitable springs so as to secure it firmly in position and
prevent the apparatus from sliding along the joist.
Mounted on the upper part of the frame is a sliding crosshead working in
suitable guides thereon, and formed on its upper side with a toothed rack in which
engages one end of a hand lever pivoted to a link whose remote end is pivoted to
the frame. By oscillating this hand lever the crosshead can be caused to slide
forward one tooth at a time and press against the board to be secured. A spring
connected to the crosshead automatically forces it back into its initial position
ready for a fresh operation, when released. The crosshead is automatically held in
any required position by means of a cam or nipping lever rack and pawl or other
suitable holding device.
By suitably modifying the base of the frame this apparatus can be used for
laying parquet flooring as a joiner's bench clamp or for other like purposes.
In a modified arrangement of clamp the operating hand lever above described is
replaced by a toggle lever or link arrangement one link acting as a pawl and
engaging with the toothed rack of the sliding crosshead; or one link is pivoted to
the crosshead while the other acts as a pawl and engages with a rack on the base
plate of the clamp.
In a further modification I dispense with the above described racks and pawls
and pivot the ends of the toggle links to the sliding crosshead and base plate
respectively and operate them by means of a screw.
In the accompanying two sheets of illustrative drawings =
Fig. 1 is a sectional elevation of a clamping apparatus constructed according to
this invention and adapted to grip on a joist, and Fig. 2 is a plan of the same.
Figs. 3 and 4 are similar views to Figs. 1 and 2 respectively showing a
modification adapted to grip on a boarded floor.
Referring to Figs. 1 and 2 the sole or base plate a has its underpart formed as a
saddle b adapted to embrace the upper part of the joist. Levers c, formed with
serrated or rat trap jaws d, are fixed on vertical shafts e mounted in the saddle b.
Spiral springs received in recesses in the saddle 6 act on the ends g of the levers c
and tend to press the jaws towards one another. The shafts e are arranged in front
of the jaws. When in use the saddle is placed over a joist and the springs fpress
the jaws against the joist. On any backward pressure being applied to the sliding
crosshead & the teeth of the jaws are forced into the joist and prevent the base or
sole plate a being forced backwards. The outer ends of a pair of toggle links i, 1,

page_text: are connected respectively to the sliding crosshead and to the rear of the base or
sole plate a and their adjacent ends are pivoted to the head m adapted to be
operated by the screw n working in a nut o on the frame and operated by the hand
wheel p. The nut may be inclined to bring the screw in direct line of the thrust
or made to swivel.
In a modified arrangement the forward end of the link i is formed like a ratchet
tooth and engages in a rack on the crosshead h. Each depression of the screw
moves the crosshead forward a distance corresponding to one tooth where it is held
by a friction or other suitable clutch that can readily be released. A spring tends
to return the crosshead to its normal position.
In another modification one of the links is prolonged to form a handle by which
they are operated in lieu of the screw.
Figs. 3 and 4 show a further modification adapted for laying parquet flooring, or
for a joiner's bench clamp. The saddle b is replaced by the spiked plates r arranged
at the front of the sole plate a in recesses in its under side.
In order that the sole plate when in use may firmly bed itself on its support its
back end is provided with an adjustable heel s pivoted to the sole plate at t and
acted on by the spring v. This heel is forced inwards as the teeth enter the
support.
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. In a clamping apparatus for laying floors and for other purposes the com-
bination with a sole plate, of a saddle piece attached to the sole plate and adapted
to embrace a joist, and of jaws pivoted to the saddle piece and adapted to
automatically grip the joist, substantially as described.
2. The clamping apparatus for laying floors and for other purposes substantially
as described with reference to Figs. 1 and 2.
3. The clamping apparatus for laying floors and for other purposes substantially
as described with reference to Figs. 3 and 4.
Dated this 8th day of February 1894.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.