Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
Wo 95/18280 2 1 7 q q O (~ PCT/CA94/00709
LIFTING AND S~ORING ~JACK ASS~MBLY
FIELD OF THE INVENTION
This invention relates to load bearing support
5 columns, and in particular to an adjustable lifting and
shoring j ack assembly .
BACKGROUND TO THE INVENTION
Adjustable support posts or columns are well known
10 in the art. Typically, convPnt;r~n~l support columns, such
as lifting jacks for liting and supporting of various
structures employ a single, threaded support rod disposed in
a main column. Many of these assemblies comprise a main
column composed of two or more telescoping elements which
15 can be ~'Yt~n~Pd and locked at predetermined intervals, such
that the column can be adjusted to a length which is
slightly shorter than that which is actually required. The
threaded support rod, which may either engage an internal
screw in the main column or an adjusting nut which bears on
20 the top of the column, is then PYtPn~Pr~ as re~uired to
support and/or raise the structure in question.
For example, ~nited States Patent No. 3,027,140
(E~ol~bach) discloses an adjustable element which is adapted
to be ~uickly and removably fitted to a fixed length column.
25 The disclosed adjustable element comprises an adjusting
screw and nut, a bearing plate, and a base plate. The
adjustable element is ;ntPn~ to be used in conjunction
Wo 95118280 2 l 7 9 9 0 0 PCTIC~94/00709 ~
with a column or po3t which i3 obtained separately, and cut
approximately to length, by the user, on 3ite.
However, in 30me case3 it is nece33ary to raise
the 3tructure by a 3ubstantial di3tance. For example, when
5 a hou3e or other 3tructure i8 ~ acked to permit moving of
3ame, or to rai3e it3 foundation, it i3 frequently found to
be nf~ ry to rai3e the 3tructure by one metre or more.
However, conv~n~ n~l jack po3ts of the type di3closed in
United States Patent No. 3,0~7,140 tend to become unstable,
lO and prone to buckling, due to the extreme length of the
adju3ting screw extending from the fixed length column
portion .
United State3 Patent No. 4,872,634 (Gillaspy et
al) disclo3es a brace a3~3embly which con3i3t3 of a main
15 brace and a pair of 3ide brace3 pi~otally attached thereto.
The length of the main brace i3 ad~ustable by mean3 of
threaded coupling3 mounted on the e~ds thereof ~ach of the
threaded coupling3 con~i3t3 of a length of threaded rod
slidably fitted within the hollow main brace, and a nut
20 which bear3 again3t an end 3urface of the main brace. A
- t; n~ bracket i3 pivotally f itted to the free end of each
of the 3ide brace3 to permit the side brace3 to be attached
to a portion of a member being 3upported (i.e. a wall), or
to 30me other J3tructure (E~uch a~ a floor), 80 a~ to lend
25 3tability to the main brace.
However, since the 3ide brace3 are of fixed
length, the extent to which the main brace can be ~t~n~lF.r~
2 1 79900
~ Wo 95/18280 PCT/CAs4/00709
af ter the side braces have been attached is severely
limited. Accordingly, a supporting system such as that
disclosed in United States Patent No 4, 372, 634 is of
limited use in situations where a structure being supported
5 must be lifted through a substantial distance
Finally, when used to support a structure of
substantial weight, a jack post tends to be forced downwards
into the earth. Typically, the base plates provided on
convPnt; l n~l jack posts do not distribute the weight over
lO sllffi~iPnt surface area to prevent from undue sinking of the
post into so_t and/or unprepared arth. Thu8 the safe and
effective use of convPntil~n;~1 jack posts is often impossible
under these conditions.
15 SUMMI~RY 0~ TE~ VENTION
It is therefore an object of the present invention
to provide an adjustable lifting and shoring jack assembly
capable of lifting a load through a substantial distance,
and which can be saf ely and ef f ectively used on sof t and/or
2 0 unprepared earth .
According to an aspect of the present invention,
there is provided a lifting and shoring jack assembly
comprising: baseplate means, said baseplate means being
capable of distributing load f orces over a suf f iciently
25 large surface area to subst~nti ~lly prevent said jack
assembly from sinking into soft earth when subjected to a
load; support column means removably disposed on said
Wo 95118280 PCT/CA.94/00709
2 1 799oQ
ba6eplate means; jack screw means slidably disposed within
said support column meang and at leaat partially P~ nf~; n~
therefrom; jack nut means operatively engaged with said
screw means, and bearing on an end surace of said support
5 column means; load plate means disposed on a ~ree end of
said screw means and capable of load bearing engagement with
a load to be ~upported; and at least two side brace means
pivotally ~--nn~ct~-l to said column means, each of said side
brace means comprising: a resE)ective elongate brace arm
lQ pivotally connected at an end thereof to said support column
means; respective length ad~usting means disposed at a free
end of each of said brace arms for adjusting the length of
each of said brace arms; and respective load ~n~a~; n~ means
pivotally disposed on said respective adjusting means to
15 facilitate load bearing engagement between the load to be
supported and each oi said side brace means.
In a pref erred embodiment, the column means is
removable irom the base plate means, thereby permitting the
assembly to be ~ a ' 1.ed for ease of storage and
2 0 transportation .
In a further preferred embodiment, the liting and
shoring ~ack assembly is further provided with a second
supporting column comprising secondary support column means
removably disposed on said baseplate means; extension screw
25 means slidably disposed within said secondary support column
means and at least partially extending therefrom; extension
nut means operatively enga~ed with said extension screw
WO9~/18280 21 7 9 0 0 PCTIC~g~tO0709
means, and bearing on an end surf ace of said secondary
support column means; and j ack means dispo3ed on a f ree end
of said screw means and capable of load bearing engagement
with a load to be supported.
Preferably, the jack means i8 a hydraulic jack.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects, features and advantages of the
invention will become apparent from the following
description of a preferred I ' o~ t when read in
conjunction with the ~rrrn~r~nying drawings, in which:
Figure l is a perspective view illustrating a
first embodiment of the present invention;
Figure 2 is a side view showing the embodiment of
Figure 1 i~ cross-section;
Figure 3 is a perspective view illustrating a
second ~mho~l; ' of the present invention;
Figure 4 is an elevation view illustrating an
~it-nt of the present invention in u3e for supporting
and raising a building;
Figure 5 is a plan view illustrating the pl;~rf~mF~t
of several j ack asflr-h1; e~ according to the invention in
relation to a b~ 1; n~ being supported and raised;
Figure 6a is a perspective view illustrating a
- 25 third embodiment of the present invention; and
Figures 6b and 6b are partial cross-sectional
views through the main column of the embodiment of Figure 6a.
Wo 95/18280 PCT/CA94/00709 ~
z7 79y~o
It 3hould be noted that thLul~lLuu~ the figures,
like P1~ tR are i~f:'nti f;~tl by like reerence numerals.
DETAILED DESCRIPTION OF ~ ;K~ EMBODIMENTS
Referring: to Figures 1 and 2, the ~ack a3sembly
comprises a ba3eplate 1, and a main support assembly 2. The
main support assembly 2 comprises a hollow main column 3
mounted on the baseplate 1, a jack screw 4 slidably disposed
within the main column 3 and at least partially PYtf~n~l;
10 thererom, a jack nut 5 in threaded engagement with the jack
screw 4, and bearing on the end surface o~ the main column
3, and a load plate -6 mounted on the exposed ~ree end of the
jack screw 4. At least two side braces 7 (three are
illustrated in Figure 1) are pivotally mounted on the main
15 column 3. ~ach of the 3ide braces 7 are designed to be
adjustable in length as the load to be supported
(dia~ t;c~l represented in Figure 1 by beams 24) is
raised by the main support assembly 2, and include a
respective load plate 6a which facilitates engagement with
20 the load to be supported. Conveniently, the side braces 7
can have a construction similar to that of the ~ain support
as3embly 2, in that they can comprise a hollow brace arm 8
pivotally connected to the main column 3, a length of
threaded rod 9 slidably mounted within the brace arm 8, and
25 an adjusting nut 10 in threaded engagement with the threaded
rod and bearing on the end 3urf ace o the brace arm 8 .
Wo 95/18280 2 1 7 ~ q 0 0 PCT/CA94/00?09
The baseplate can have any desired conf iguration,
provided that it offers a large "footprint", so that heavy
loads can be securely supported by the jack assembly, even
when used on soft and/or unprepared earth. Conveniently,
the baseplate 1 will consist of a generally square or
rectangular bottom E?late 11, a centrally-located column seat
12 for receiving the main column 3, and a set of generally
radially oriented stiffening ribs 13 for transferring load
forces outward towards the periphery of the bottom plate 11.
The bottom plate and stiffening ribs 13 can conveniently be
constructed of steel plate, and the column seat 12 from
hollow round structural steel, the entire baseplate 1 being
fastened together by, for example, welding.
The interior diameter of the column seat 12 is
suitably sized with respect to the outside diameter of the
main column 3, so that the main column 3 is held securely
therein during use of the j ack assembly, but can be readily
removed therefrom for ease of transportation. However, the
main column 3 can be permanently fastened in the column seat
12, for example by means of welding, in cases where
disassembly for ease of tranElportation is not a
consideration .
The main column 3 is conveniently constructed of
hollow tubular steel, and will be sized appropriately
25 according to the loads to be supported. Similarly, the jack
screw 4 and jack nut 5 will be suitably sized according to
the oad to be supported. In addition, the outer diameter
Wo 95118280 2 l 7 9 ~ ~ PCT/CA94100709 ~
of the ~ack screw 4 will be selected to provide a clear
sliding fit within the main column 3. However, the fit
between the jack screw 4 and the ;nt~;nr of the main column
3 must be close enough to substantially prevent an angular
5 offset between the main column 3 and ~he Jack screw 4 (with
the attendant increased bending stresses and risk of
buckling). The length of the jack screw 4 will be selected
according to the desired distance through which the load is
to be liftea, but can conveniently be approximately the same
lO length as that of the main column 3, thereby allowing jack
assembly to lift the load to be supported through a di~tance
as close as possible to the height of the main column 3.
~ :ach of the side brace 7 is pivotally attached to
the main column 3 by means of respective pins or bolts and
1~ ~upport lugs 14 attached to the ~XtF~ n7` of the main column
3 (for example by means o~ welding) 80 as to not interfere
with m~,v t of the ~ack screw within the main column 3.
In use, the ~ack assembly is located under a load
to be supported (see Figure 4), and the load plates 6 and 6a
20 of the main support assembly 2 and side braces 7,
respectively, are attached to the load to be supported, such
as a h~ ii nS 26 and/or temporary support beams 24 located
under the b~ n~ 26 to facilitate the ~acking thereof
(note that in figure 4, only one side brace 7 is shown for
2~ clarity. ) . If desired, the base plate l can be secured
against lateral ~sliding) movement by the use of s~akes 26
driven into the ground. The j ack screw is then turned in a
Wo 95~18280 2 l 7 9 9 0 0 PCT/CA94100709
direct to extend the j ack screw 4, f rom the main column 3,
so as to raise the load to be supported, through a desired
distance. As the load to be supported is raiaed by the main
support assembly 2, the threaded rods 9 of the side braces
7 are pulled outwards from their respective brace arms 8.
As this occurs, the adjusting nuts 10 are turned in order to
m-int~in each of the gide braces in compression, so that at
least some of the weight of the load being supported is
transferred to the main column 3 through the side braces 7.
The maintenance of a compressive loading in each of the side
braces 7 serves two purposes. First, it reduces the load
forces acting on the jack screw 4 and jack nut 5, thereby
making the jack nut 5 easier to turn. Second, the forces
exerted by the side braces on the main column 3 tend to
brace the main column 3 against bucking, thereby increasing
the effective load carrying capacity of the jack assembly of
the invention.
Figure 3 illustrates a second embodiment of the
j ack assembly of the present invention . This second
embodiment retains the base plate l, main support assembly
2, and side braces 7 described in respect of the f irst
~mhr~; ' . Accordingly, these elements will not be further
discussed in detail. The lifting and shoring jack assembly,
according to the second embodiment of the invention, is
25 provided with a secondary support assembly 16 comprising a
secondary support column 17 mounted on the baseplate l; an
extension screw 18 slidably disposed within the secondary
Wo 95/18280 2 1 7 9 ~ 0 ~ PCTICAg4/00709
support column 17 and at least partially P'~t~n~;nS
therefrom; an extension nut 19 engaged with the extension
screw 18 and bearing on an end suri~ace of the secondary
~upport column 17; and a lifting jack 20 mounted at the top
5 of the extension screw 18.
The secondary support column 17 is preferably
mounted OIl the baseplate 1, by mean3 of a secondary support
column seat 21 in .oq~:~nt;~lly the same manner as the main
column 3. In addition, the secondary support column 17 is
10 removably coupled to the main column 3, at least during use,
by means of a bolt (or the like) and lugs 22 affixed near
the top of ~ecr~ ry support column 17 and the main column
3.
The operation of the j ack as~embly according to
15 the second ~ ; t of the invention is essentially the
same as that of the f irst embodiment, except that in this
case, the lifting jack 20 (which preferably compri~es a
conv~nti~n~l hydraulic or pneumatic jack) is used to lift
the load being support through a small distance; the jack
20 nut 5, and ad~usting nuts lo are the tightened 80 that the
main support assembly 2 and side braces 7 carry the weight
of the load being supported; the lifting jack 20 is then
released 80 that the extension nut l9 can be turned to
extend the extension screw 18, thereby raising the lif ting
25 jack 20 without lifting the load being carried. By this
means, the load being supported can be raised through a
Wo 9~/18280 ~ ~ 1 PCT/CA94100709
11
3eries of comparatively small in~L~ ~l steps, thereby
ensuring safe operation of the jack assembly.
As a further safety measure, additional side
support lugs 23 can be provided near the top of the main
column 3. These additional lugs permit a further set of
side braces 7 to be mounted on the main column 3, thereby
increasing the h~ kl in9` resistance of the main support
assembly 2. In addition, the baseplate 1 can be modified as
desired to provide additional reinf~.l~ t to the central
portion of the bottom plate 11, particularly under the main
support assembly 2 and the secondary support assembly 16.
Figures 4 and 5 illustrate the use of the jack
assembly according to the present invention for supporting
and raising a b~ n~ 25. Figure 4 present~ an elevation
view of a jack assembly being used, while Figure 5 presents
a plan view showing the general locations of each of the
jack ~FIsF~mhl les used, along with supplementary supporting
beams or timbers 24 and bracing stakes 26 in relation to the
building 25 being supported and lifted.
2 0 In order to ensure ade~uate support of the
building 25, while it is being lifted, a set of lateral and
longit-l-~;n:3l support beams (or timbers) 24 are preferably
provided under the b~ lin~ 25. A number~of jack assemblies
~in the present example, ~ix are employed) are then
installed such that the main support assemblies 2 thereof
are positioned under the respective intersection points of
the beams 24. At this point, E~ide braces 7 are mounted on
Wo 95118280 PCT/CA94/00709
~ 1 799oo
12
each of the respective main support columns 3, and attached
to the beams 24, generally as illustrated in Figures l, 4
and 5 . Following the installation of t~e beams Z4 and j ack
assemblies, in this manner, the b~ n~ 25 can be raised by
5 operating each of the jack assemblies in the manner
described above in connections with Figures 1-3. In tests
performed by the inventor, two houses (one measuring
approximately 30' by 40' ) were successfully raised by this
method. During one of these tests, the house in question
lO was subjected to winds in ~excess of lOo km/hr without ill
effect .
Figure 6a is a perspective view illustrating a
third ' r~ t of the present invention. This third
embodiment can be considered as a modif ication of the
lS embodiment of the inventio~ described above in connection
with Figure 3. -In this case, however, only two side braces
7 pivotally attached to the main column 3 by means of
respective pins or bolts and support lugs 14 attached to the
~ t~r1nr of the main column 3. A hook assembly 30 is
20 mounted on the main support assembly 2, opposite the
secondary support assembly 16, and is designed to engage
(and lift) a load dispo3ed near the ground.
The hook assembly 30 comprises a pressure plate 31
capable of bein~r bolted to the load plate 6 of the main
25 support assembly 2. A sl1~p~ntl~r 32 is affixed to the
pressure plate 31, for example by means of welding. In
addition, r~1 nfrrr1 n~ plates 33 can be provided reinforce
Wo 9S/18280 2 1 7 9 9 0 0 PCT/CA94/00709
the pressure plate and strengthen the connection between the
pressure plate 31 and the sll~pPn~l~r 32. At the base of the
suspender 32, a lifting hook 34 is provided for engaging a
load. The length of the suspender 32 is preferably
5 det~rm;nP~ 80 that, when the main support assembly 2 is
lowered to it greatest extent, the lif ting hook 34 is
capable of being operatively positioned beneath a load which
is close (for example, less than approximately 200mm) to the
ground .
In order to brace the lifting hook 34 against
undesired movement, a roller 35 is conveniently mounted on
the suspender 32, preferably in the vicinity of the lifting
hook 34, 80 as to bear against the main column 3.
Pref erably, the roller is provided with an hour-glass
profile, as illustrated in Figure 6b, which allows the
roller 35 to operatively engage the side of the main column
3 in such a manner as to resist lateral (i.e. side-to-side)
motion of the lifting hook 34. In order to permit the
roller 35 an unobstructed path along the length of the main
column 3, no lugs 14, 23 (see Figure 3) are provided for the
installation of side braces 7 on that side of the main
column 3. However, 1~ it is desired to remove the hook
assembly 30, mounting brackets 36 can be installed as
illustrated in Figure 6c. The mounting brackets 36 are
conveniently designed to be supported on the lugs 14, 23
welded on opposite sides of the main column 3. By means of
the mounting brackets 36, a third side brace 7 can be
WO 9s/l8280 PCT/CA94100709
2 1 79900
14
mounted on the main column 3, and the j acking assembly used
in the same manner as the embodiment illustrated in ~igure
3.
It will be appreciated that, while the present
invention ha~ been described in connection with three of its
embodiments, it is by no means limited to same, but may
instead by varied within t~e scope of the appended claims.
INDUSTR~L APPI ICA3ILITY - -
As will be clear from the forgoing de3cription,
the present invention can be used singly or in combination
to support and lift heavy loads, and is particularly suited
to lif ting heavy loads while standing on uneven or
unprepared 80il. As such, in addition to the specific
application described in detail above, the present invention
is applicable (but is by no means limited) to 3uch diverse
areas as emergency supports ~e . g . in an earthquake disaster
area), lifting heavy equipment (e.g. construction e~auipment)
for carrying out hard-to-reach maintenance or repair work,
and in mining industries.
