Lifting jack

A lifting jack, particularly useful in supporting wall cabinets and the like during installation and attachment to a wall surface, includes an elongated standard, adjustable for major height adjustments, mounted on an adjustable base, and a platform secured to a fine-adjustment mechanism mounted on the upper end of the elongated standard for engaging and supporting the cabinet during installation.

BACKGROUND OF THE INVENTION 
This invention relates to lifting jacks and, more particularly, to lifting 
jacks that are particularly well adapted for lifting and supporting 
cabinets and the like for attachment to a wall surface. 
Heretofore, when cabinets have been installed and attached to a wall 
surface, it has commonly required the services of two or more people 
because one or more persons were requires to support the cabinet in proper 
position while the other person secured or attached the cabinet to the 
wall to which it was to be supported. Thus, it is an important object of 
the present invention to enable such wall cabinets and the like to be 
installed by a single person. 
Jacks, of course, have been heretofore known in the art being shown, for 
example, in U.S. Pat. Nos. 1,192,611, issued to W. A. Field; 2,810,824, 
issued to P. Kaufman; 2,823,958, issued to C. W. Terry; 3,606,254, issued 
to O. W. Olson and 3,642,243, issued to Smith Eugene. However, it is an 
important object of the present invention to afford a novel jack for 
lifting and supporting wall cabinets, and the like, which constitutes 
improvements over such jacks known in the art. 
SUMMARY OF THE INVENTION 
A primary object of the present invention is to afford a novel lifting jack 
which is particularly well adapted for lifting and supporting cabinets and 
the like for attachment to a wall surface. 
Another object of the present invention is to make the installation and 
hanging of wall cabinets more efficient and easier, even when more than 
one person is being used in the operation. 
Yet another object of the present invention is to afford a novel jack of 
the aforementioned type which is quickly and easily adjustable to various 
heights and which is adapted for use on uneven supporting surfaces. 
A further object of the present invention is to afford a novel jack of the 
aforementioned type, the height of which may be accurately adjusted to the 
desired height. 
Another object of the present invention is to afford a novel jack of the 
aforementioned type which is practical and efficient in operation, and 
which may be readily and economically produced. 
Other and further objects of the present invention will be apparent from 
the following description and claims and are illustrated in the 
accompanying drawings which, by way of illustration, show a preferred 
embodiment of the present invention and the principles thereof and what I 
now consider to be the best mode in which I have contemplated applying 
these principles. Other embodiments of the invention embodying the same or 
equivalent principles may be used and structural changes may be made as 
desired by those skilled in the art without departing from the present 
invention and the purview of the appended claims.

DETAILED DESCRIPTION 
Referring now to the drawings wherein like numerals have been used 
throughout the several views to designate the same or similar parts, a 
lifting jack assembly 1 in accordance with one embodiment of the present 
invention is shown in FIGS. 1-4. 
In general, the lifting jack 1 includes an elongated standard 2 disposed in 
substantially upright position on a base 3 and having a platform 4 
adjustably connected to the upper end portion of the standard 2 by an 
adjustment means or member 5. 
The base 3 includes an elongated, tubular central body portion 6 disposed 
in substantially upright position at the inner ends of three legs 7, 8 and 
9, which project radially outward therefrom in substantially equally 
spaced relation therearound. Each of the legs 7, 8 and 9 may include an 
adjustment member 10 mounted in the outer end portion thereof, and 
vertically adjustable relative thereto for leveling, or adjusting the 
position of the base 3. Although it is preferred to have each leg include 
an adjustment member 10, it is only necessary that two of the legs include 
an adjustment member for proper leveling of the jack assembly 1. As shown 
in FIG. 3, each of the adjustment members 10 embodies an elongated bolt 11 
threadedly engaged in the outer end portions 33, 34 and 35 of a respective 
one of the legs 7, 8 and 9, with each of the bolts 11 having a foot or 
base portion 12 disposed at the lower end thereof for engaging the floor 
or other supporting surface on which the base 3 is mounted, and a knob 13 
mounted on the upper end portion thereof for rotating the bolt 11 to 
thereby adjust the vertical position thereof in the respective one of the 
legs 7, 8 and 9. 
The elongated standard 2 embodies a lower end portion or member 14 and an 
upper end portion or member 15, which are releasably and adjustably 
connected together in a manner which will hereinafter be discussed in 
greater detail. The lower end portion 14 of the standard 2 is a 
substantially straight tubular member having an outside diameter of such 
size that the lower end portion thereof may be disposed in the body 
portion 6 of the base 3 with a relatively snug, but freely slidable fit. A 
bolt 16 is threaded into and extends through the sidewall of the body 
portion 6 of the base 3 in such position that it may be rotated into and 
out of the body portion 6 and into and out of abutting, securing relation 
to the portion of the lower end portion 14 of the standard 2 disposed in 
the base 3. 
The upper end portion 15 of the standard 2 embodies a lower end 17 (FIG. 2) 
which is of such external size or cross-section that it may be received in 
the upper end portion of the lower end portion 14 of the standard 2 with a 
snug, but freely slidable fit. Lower end 17 may be of substantially the 
same length as the standard 2 to provide maximum extended length of the 
jack 1 or a proportionally shorter length thereof, as desired. A bolt 18 
is fitted into a nut 19, mounted on and secured to the outer face of the 
sidewall of the lower end portion 14, the bolt 18 extending through the 
lower end portion 14 of the standard 2 in position to be moved into and 
out of abutting relation with the lower end portion 17 of the upper end 
portion 15 of the standard 2 upon rotation of the bolt 18. A handle 20 
preferably is mounted on the outer end portion of the bolt 18 for 
facilitating rotation of the bolt 18. 
The upper end portion 15 of the standard 2 includes an upper end member 21, 
connected to the lower end portion 17 by an intermediate portion 22, FIG. 
2. The upper end member 21 includes an internally threaded bore 23, FIG. 
4, extending substantially vertically there-through in axial alignment 
with the lower end 17 of the upper end portion 14. 
The adjustment member 5 embodies a bolt or feed screw 24 extending through 
and threadedly engaged with the bore 23 in the end portion member 21, the 
feed screw 24 having an enlarged head 25 on the upper end portion thereof, 
which is rotatably mounted in an upwardly opening recess 26 in the upper 
face of a connector member 27, FIG. 4, the connector member 27 being 
secured to the lower face of the platform 4 by suitable means such as 
bolts or screws 28, FIG. 2, to thereby retain the head 25 of the feed 
screw 24 in the recess 26. The connector member 27 has an elongated member 
or shaft 29 projecting downwardly therefrom in parallel relation to the 
feed screw 24, and extending through an opening 30 in the upper end 21 of 
the upper end portion 15 of the standard 2, FIG. 4, for preventing 
rotation of the platform 4 around, or with the feed screw 24 relative to 
the standard 2. Rotation of the feed screw 24 relative to the bore 23 in 
opposite directions is effective to raise and lower the feed screw 24 and 
the elongated member 29 in the bores 23 and 30, respectively, between 
raised and lowered positions, such as, for example, the positions shown in 
broken and solid lines, respectively in FIG. 2. A member, preferably in 
the form of a handle 31, is mounted on the lower end of the feed screw 24 
for effecting such rotation of the latter and thereby adjusting the 
vertical position of the platform 4 relative to the standard 2. 
In the lifting jack assembly 1, the bore 23 and the feed screw 24 
preferably extend through the end 21 of the upper end portion 15 of the 
standard 2 in axial alignment with the lower end 17 of the upper end 
portion 15 and with the lower end portion 14 of the standard 2, FIG. 2. 
The intermediate portion 22 of the upper end portion 15 of the standard 2 
is offset laterally relative to the upper end 21 and lower end 17 of the 
upper end portion 15, as well as to the handle 31, to thereby permit the 
handle 31 to be readily rotated for manually turning the feedscrew 24 in 
the bore 23. However, it will be seen that, even with the intermediate 
portion 22 of the upper end portion 15 of the standard 2 thus disposed in 
laterally outwardly projecting position, with the upper end 21 and the 
lower end 17 of the upper end portion 15 of the standard 2 disposed in 
substantially vertical, axial alignment with each other and with the lower 
end portion 14 of the standard 2, a stable, balanced support for the 
platform 4 is afforded. 
As will be appreciated by those skilled in the art, with the lifting jack 1 
constructed in the aforementioned manner, a readily operable effective 
lifting jack is afforded for supporting and raising and lowering articles, 
such as, for example, cabinets and the like, and such operation may be 
readily effected by one person. 
Thus, for example, if the jack 1 is to be used to support a wall cabinet, 
or the like, in position to be secured to a wall, the handle 20 may be 
turned to release the engagement of the screw 18 with the upper end 
portion 15 of the standard 2 and thereby permit the upper end portion 15 
of the standard 2, together with the platform 4 mounted thereon, to be 
raised or lowered to the appropriate desired position of the platform 4. 
The cabinet, not shown, may then be disposed on the platform 4 in position 
to be supported thereby and by rotating one or more of the members 10 on 
the base 3, the position of the base 3 relative to the underlying 
supporting surface may be adjusted to thereby dispose the platform 4, and, 
therefore, the cabinet, not shown, in the desired position relative to the 
horizontal. 
Thereafter, the handle 31, and, therefore, the feed screw 24, may be 
rotated in the proper direction to thereby raise or lower the feed screw 
24 and the platform 4, relative to the standard 2, to thus position the 
platform 4 and the cabinet, or the like, disposed thereon at the proper 
elevation with respect to the wall surface. Then the user may readily use 
the selected tool or drill from the tool or drill holder 38, which is 
conveniently mounted on the standard 2, to secure the cabinet onto the 
wall surface. After the cabinet has been secured to the wall surface, the 
handle 31 may be rotated to lower the platform 4 out of supporting 
relation to the cabinet, and the lifting jack 1 may be removed for use 
with another cabinet. 
In FIG. 5, a modified form of the present invention is shown, and parts 
which are the same as parts shown in FIGS. 1-4 are indicated by the same 
reference numerals, and parts which are similar to but are different from 
parts shown in FIGS. 1-4 are indicated by the same reference numerals with 
the suffix "a" added thereto. 
Thus, it will be seen that in FIG. 5, a lifting jack 1a is shown, which is 
substantially the same in construction as the jack 1, shown in FIGS. 1-4, 
except that the lower portion 14 of the standard 2 has been eliminated and 
one leg 9a of the base 3a does not have an adjustable member 10 mounted 
thereof but, instead, has a stationery member 10a, which may be an 
integral part of the leg 9a, disposed thereon. 
The jack 1a is intended for use, primarily, in operations where the bottom 
of the cabinet, or the like, being installed, is not disposed a 
substantial distance above the supporting surface, or where the relatively 
extensive vertical adjustment afforded between the end portions 14 and 15 
of the standard 2 are not necessary, such as, for example, when a cabinet 
is being installed above a previously installed cabinet. 
In the operation of the jack 1a, the base 3a may be disposed on the 
available supporting surface, such as, for example, the top of a 
previously installed cabinet, and the end portion 17 of the standard 2a 
may be mounted directly into the body portion 6 of the base 3a, and 
secured in position therein by tightening the bolt 16. Thereafter, the 
cabinet, or the like, may be mounted on top of the platform 4, and the 
level thereof adjusted by adjusting the adjustment members 10 in the legs 
8 and 9 to the necessary position. The handle 31 may then be turned in the 
proper direction to rotate the screw 24 and raise or lower the platform 4 
to thereby dispose the cabinet, or the like, at the desired elevation 
above the supporting surface on which the base 3a is mounted. After the 
cabinet, or the like, has been secured in position, the platform 4 may be 
lowered out of engagement therewith by rotation of the handle 31 in the 
proper direction and the lifting jack 1a may be removed from the proximity 
of the latter. 
From the foregoing, it will be seen that the present invention affords a 
novel lifting jack which is particularly well adapted for use in 
operations such as, for example, supporting wall cabinets, and the like, 
in proper position, during installation operations relative thereto. 
In addition, it will be seen that the present invention affords a novel 
lifting jack which enables a single user to support and install articles, 
such as, for example, wall cabinets. Also, it will be seen that the 
present invention affords a novel lifting jack which is practical and 
efficient in operation, and which may be readily and economically produced 
commercially. 
Thus, while I have illustrated and described the preferred embodiments of 
my invention, it is to be understood that these are capable of variation 
and modification, and I therefore do not wish to be limited to the precise 
details set forth, but desire to avail myself of such changes and 
alterations as falls within the purview of the following claims.