Portable and towable lift mechanism

An improved lift mechanism that is portable and towable, and has a telescopic and angularly adjustable load carrying boom, four telescopic support legs with pivotable wheels thereon, and a low center of gravity frame of a two part construction pivotally connected together and having a tilt indicator warning thereon.

BACKGROUND OF THE INVENTION 
1. Technical Field 
The present invention relates to cranes or lifts. More particularly, the 
present invention relates to portable and towable cranes or lifts that are 
capable of safely lifting thousands of pounds and/or telescoping to 
distances approaching or beyond 30 feet at angles of between substantially 
horizontal to almost vertical while also being capable of compact storage 
for towing. Specifically, the present invention is a portable and towable 
lift mechanism having a telescopic and angularly adjustable load carrying 
boom, four telescopic support legs with pivotable wheels thereon, and a 
low center of gravity frame of a two part construction pivotally connected 
together and having a tilt indicator warning thereon. 
2. Background Information 
For hundreds of years, people have needed and/or desired to lift or move 
heavy or bulky objects. More particularly, people have needed and/or 
desired to vertically or substantially vertically lift heavy or bulky 
objects up into the air, to suspend heavy or bulky objects angularly 
outward and at least slightly in the air, or to both lift and suspend the 
object. Often these needs occur for one of two reasons, a bulky and/or 
heavy object either (1) needs lifted into the air for a temporary time or 
to be placed on a surface or suspended from a frame in the air, or (2) 
needs lifted over an obstacle and set down on the other side. 
Current technology includes large relatively or completely immobile cranes. 
These cranes are generally used on construction sites where the crane is 
transported via trailer by large trucks such as tractor-trailers. These 
large cranes are expensive to own or rent, not portable or hard and time 
consuming to move, not towable as trailering is typically necessary, not 
readily transported to remote sites, not easily positioned as needed in 
tight spots (often not possible), etc. 
Alternatively, many manufacturers of cranes, lifts, and hoists have 
attempted to downsize this large crane technology to a smaller, more 
affordable, and user friendly lift. The result is often an unstable, 
dangerous, and otherwise undesirable lift that includes an insufficient 
frame for supporting substantial loads. Theses small lifts are often 
sufficient for small jobs such as lifting car engines weighing several 
hundred pounds, but are generally not capable of lifting substantial 
weights of approaching if not exceeding a thousand pounds, if not more. 
These booms often are inferior and hard to use, and may be capable of 
lifting only a small weight safely. Finally, these lifts either have fixed 
booms or extendible booms of only a small distance such as a few feet 
upwards to approximately ten feet. 
OBJECTIVES AND SUMMARY OF THE INVENTION 
It is an objective of the present invention to provide an improved crane, 
lift or hoist. 
It is further an objective of the present invention to provide an improved 
portable crane, lift or hoist. 
It is further an objective of the present invention to provide an improved 
towable crane, lift, or hoist that is towable at highway speeds. 
It is further an objective of the present invention to provide an improved 
crane, lift or hoist of a retracted size equivalent to a standard vehicle 
tow behind trailer of an approximately 6 to 8 foot width (a width that 
does not require wide load designation and have limited transportation due 
to road and daylight restrictions) and approximately 8 to 12 foot length 
(standard trailer length). 
It is further an objective of the present invention to provide an improved 
trailer sized crane, lift or hoist that is stable during both towing and 
fully extended use. 
It is further an objective of the present invention to provide an improved 
trailer sized crane, lift or hoist that extends to approximately between 8 
and 12 feet in width and approximately between 10 and 16 feet in length. 
It is further an objective of the present invention to provide an improved 
trailer sized crane, lift or hoist that is capable of safely lifting 
thousands of pounds. 
It is further an objective of the present invention to provide an improved 
trailer sized crane, lift or hoist that includes a telescoping boom that 
is capable of retraction to between approximately 6 and 8 feet in length 
while extendible to approximately between 20 and 35 feet in length. 
It is further an objective of the present invention to provide an improved 
trailer sized crane, lift or hoist that includes a telescoping boom that 
is capable of loaded angular adjustment from approximately 5.degree. to 
15.degree. below horizontal to approximately 75.degree. to 85.degree. 
above horizontal. 
It is further an objective of the present invention to provide an improved 
trailer sized crane, lift or hoist that includes a two part load 
supporting frame that is pivotally connected. 
It is further an objective of the present invention to provide an improved 
trailer sized crane, lift or hoist that includes a tilt indicator 
mechanism for displaying unsafe loads and/or angles in combination with 
loads. 
It is further an objective of the present invention to provide an improved 
trailer sized crane, lift or hoist that includes a safety switch that 
deactivates the lifting and/or extending of the boom. 
It is further an objective of the present invention to provide an improved 
trailer sized crane, lift or hoist that includes a mechanism or 
construction that assures properly sequenced telescoping of the boom. 
Still other advantages and benefits of the invention will become apparent 
to those skilled in the art upon a reading and understanding of the 
following summary and detailed description. 
Accordingly, the present invention satisfies these and other objectives as 
it relates to lift mechanisms.

Similar numerals refer to similar parts throughout the drawings. 
DESCRIPTION OF THE PREFERRED EMBODIMENT 
The improved lift mechanism of the present invention is indicated generally 
at 100 as is best shown overall in FIGS. 1-13 while in detail as to 
specific elements in FIGS. 14-30D. The lift mechanism 100 is shown 
generally in perspective in FIGS. 1-4 as including a first frame 102, a 
second frame 104, a pair of rear retractable and extendible leg extensions 
(or wheel frames) 106 and 108, a rear wheel 110 and 112 on each rear wheel 
frame, a pair of front retractable and extendible outriggers (wheel 
frames) 114 and 116, a front wheel 118 and 120 on each front wheel frame, 
a selectively retractable and extendible boom 122, a boom angle actuator 
124, an actuator drive device 126 in communication with the boom angle 
actuator such as by electrical or fluid lines, a power supply 128 in 
communication with the selected parts of the lift mechanism that need 
power, a winch 130 with a controller thereon and in communication with the 
power supply such as by electrical lines, a snatch block 132, a tilt 
indicator 134, a safety switch or switches 136, a remote winch control or 
switch box 138, and a remote actuator control or switch box 140. 
First frame 102 includes a pair of legs 150 and 152 as shown in FIGS. 1-13 
and best shown in FIG. 10, each of which has a proximate end 154 and a 
distal end 156. The proximate ends 154 of the legs are adjacent one 
another while the legs diverge away from each other thereafter such that 
the distal ends 156 are spaced apart. Typically, these distal ends and 
preferably the entire leg is of a square (or rectangular) and hollow cross 
section. 
First frame 102 also includes cross supports 158 and 160 as shown in FIG. 
10 which extend between the legs. As better shown in FIGS. 6 and 7, first 
frame 102 further includes a vertical tower 162 extending upward out of 
the proximate ends 154 of the legs 150 and 152 for supporting boom 122, 
and a pair of angular supports 164 and 166 (see FIGS. 1 and 9) extending 
between the vertical tower 162 and legs 150 and 152. First frame 102 also 
further includes a pivot support plate 168 connected to the legs 150 and 
152 on the upper surface thereof, and a tongue 170 extending substantially 
horizontally and rigidly from the vertical tower 162. 
The tongue has a first rigid portion 172, a hinge 174, a second rigid 
portion 176 that is pivotal about the hinge 174, and a hitch portion 178 
with a ball hitch socket 180 therein. A sliding lock is also provided 
within, underneath, adjacent to or around the hinge 174 and at least one 
of the adjacent first or second rigid portions 172 and 176 whereby the 
sliding lock slides from a first position where hinge is locked resulting 
in a rigid and straight structure from the first to second portions as 
shown in FIGS. 1-8 to a second position where the lock does not block the 
hinge from freely pivoting (such free pivoting allowing the first rigid 
portion 172 to pivot upward about hinge 174). 
Second frame 104 includes a main axle or leg 190 of preferably a square (or 
rectangular) and hollow cross section, and a pair of pivot arms 192 and 
194. The pivot arms 192 and 194 are rigidly connected approximate one end 
to leg 190 and extend to pivot points at pivot support plate 168 where 
pivot connectors 196 pivotally connect the other end of arms 192 and 194 
to support 170. 
Specifically, the first and second frames 102 and 104 are pivotally 
connected at pivot connectors 196 which extend through a hole in pivot 
arms 192 and 194 and secure such arms to flanges 182 via holes therein 
where the flanges are extending outward from pivot support platel68. This 
allows the first and second frames to separately move during both 
transportation and loading. As will be described later, this movement 
during loading allows the tilt indicator 134 to properly show the tilt of 
the overall lift mechanism 100 or lack thereof. 
Further as to the pivot point, one end of the boom angle actuator 124 
(which is preferably a hydraulic cylinder with a drive rod that is 
actuatable into and out of hydraulic chamber) is also pivotally connected 
at pivot connectors 194 as shown in FIGS. 1-4. The other end of the boom 
angle actuator is pivotally connected to boom 122 via pivot pin 195 at 
flanges 197. The flanges 197 are rigidly affixed to the boom at a point 
spaced apart from the pivot point 198 of the boom. This pivot point is 
defined by the pivot and fastening rod 200 where the boom is attached via 
this fastening rod 200 through 3-sided mounting bracket 202, which is 
rigidly affixed to the vertical tower 162, and one end of the boom as best 
shown in FIGS. 1-4. 
Specifically, the selectively retractable and extendible boom 122 includes 
a plurality of boom sections. In the embodiment shown, boom 122 includes a 
base or main boom section 204 and four telescoping boom sections 205, 206, 
207, and 208 as best shown in FIG. 11 where the boom is fully extended 
(and shown in a number of different positions including horizontal and 
fully retracted at A, two sections extended and angled up 45.degree. at B, 
three sections extended and angled up 60.degree. at C, and four sections 
or fully extended and angled up 75.degree. at D where all of the boom 
sections are best shown). The above mentioned boom angle actuator 124 is 
pivotally connected to the main boom section 204 between its opposing ends 
and is responsible for the movement of the boom to the various angled 
positions shown in A-D. It is contemplated that the boom 122 may comprise 
more or less boom sections and still perform the same functions and/or be 
of the same dimensions overall. In one other scenario, the boom 122 has 
fewer segments such as three (3) or four (4). These segments may be of the 
same length as those described above thereby reducing the overall boom 
length, of a longer length such that the same overall boom length is 
maintained or even exceeded, or of a shorter length such that the overall 
boom length is shorter. 
The boom sections may be of a variety of cross sectional shapes including 
square as is shown in FIG. 1, rectangular, any other polygonal shapes, or 
even round or oval. The rectangular shape is one of the preferred cross 
sectional shapes as it is stronger than many other shapes when loaded in a 
cantilevered manner. 
As to the telescoping boom sections, boom section 205 is of a slightly 
smaller cross section than main boom section 204 so as to be slidable 
within the hollow main boom section 204. Similarly, boom section 206 is 
slightly smaller than boom section 205 so as to be slidable within boom 
section 205. Also similarly, boom section 207 is slightly smaller than 
boom section 206 so as to be slidable within boom section 206. Finally, 
boom section 208 is similarly slightly smaller than boom section 207 so as 
to be slidable within boom section 207. 
Each retractable boom section 205-208 has a cuff 210 with an eyelet 212 (or 
similar ring, pair of offset and overlapping "C" shapes, or other cable 
constraining devices) on its outermost end which acts as a stop to prevent 
retraction of each entire boom section into the adjacent larger boom 
section. These eyelets guide a lift cable 216 that extends from winch 130 
to snatch block 132 and serves to lift or drop any load attached to the 
hook 217 on the snatch block. 
An alternative embodiment involves lift cable 216 extending through the 
boom sections 204-208 rather than affixed on top. This would provide some 
protection from environmental elements and also assure that should a lift 
cable snap it will not wildly fly through the air. 
Some of the retractable boom sections further include stops that prohibit 
the complete removal of that boom section from the next largest boom 
section in which it slides. This functions as a positive safety stop so 
accidental boom section removal does not occur. 
Main boom section 204 also includes a reinforcement bar 214 that supports 
the winch 130. This bar may be in several pieces welded together with each 
piece bent or angled so as to best reinforce the boom (this is shown in 
the figures where the bar is actually several bars welded together to form 
a triangular shape with the surface of the boom with a middle support 
therein). 
As to each of the individual boom sections, pin receiving holes 218 extend 
through the boom sections and are selectively alignable to fix the boom 
sections within the larger boom sections that each slides within. These 
holes are arranged in a specific order so as to assure extending of the 
boom sections as desired by the manufacturer, specifically, so that the 
strongest boom sections are extended first (that is those with a larger 
cross section) since the holes in adjacent booms must align so that the 
pins 219 are insertable therethrough as are required in the holes to lock 
the boom sections in place thereby preventing retracting during loading. 
Preferably, boom section 205 extends first before any portion of sections 
206-208. Once boom section 205 is fully extended from main section 204, 
then boom section 206 is extendable to a selected length. Once again, once 
boom section 206 is fully extended, then boom section 207 is extendable to 
a selected length. Finally, once boom section 207 is fully extended, then 
boom section 208 is extendable to a selected length or its full extension. 
Alternatively, one or more of the boom sections may be designed for power 
hydraulic extension instead of manual extension and the use of pins to 
lock it in place. In one version, a power hydraulic system is attached to 
the second boom section 205 for hydraulic control of its extension and 
retraction from section 204. 
In the embodiment displayed in the FIGS., about the end or nose of boom 
section 208 is a pulley or other mechanism 220 for receiving the lift 
cable 216 and redirecting it downward toward the snatch block 132. The 
boom section 208 also includes a hook receiver 222 for receiving a hook 
224 about the end of lift cable 216. The lift cable 216 is thereby 
threaded through the snatch block 132 and affixed to the boom 122 at hook 
receiver 222. 
The snatch block 132 includes a pulley or similar device 226 for receiving 
the cable whereby a pair of plates 228 sandwich the pulley 226 thereby 
holding the cable therein. The plates 228 also hold hook 217 therein at 
one end of the plates. The other end of the plates generally includes a 
pair of aligned holes 215. The snatch block 132 is designed such that it 
may be used with the hook 217 extending outward therefrom as shown in the 
FIGS., or flip flopped whereby the snatch block may be bolted or otherwise 
secured to an object (typically an immovable object) via the holes 215. 
The hook is obviously used for lifting whatsoever it is desired to lift. 
The hook sand/or holes are also useful in that either may be affixed to an 
immovable object whereby the winch is used to move to overall lift 
mechanism. Furthermore, this method may also be used to actually lift the 
entire lift mechanism up into the air, such as to lift it up onto a roof. 
Ear 213 with a hole therein is also useful during such activities as a 
place to hook or attach hook 217. The snatch block further serves to 
provide a doubling effect to the mechanical gain of the lift when hooked 
to ear 222. 
The lift mechanism 100 also has the pair of rear retractable and extendible 
wheel frames 106 and 108 with rear wheels 110 and 112 thereon, and the 
pair of front retractable and extendible wheel frames 114 and 116 with 
front wheels 118 and 120 thereon. These wheel frames extend and retract 
from legs 150 and 152, and leg 190, respectively, so as to in a retracted 
position allow for towing of a standard sized trailer, while in an 
extended position allow for maximum stability of the lift. 
As to rear wheel frames 106 and 108 as best shown in FIGS. 1, 4-5 and 10, 
each includes a support bar 240 of a complementary (preferably square or 
rectangular) yet smaller cross section than legs 150 and 152 so as to be 
slidable within the legs. Both of bar 240 and legs 150 or 152 include a 
plurality of holes in which a lock pin 241 is insertable once proper 
positioning is achieved so as to prevent accidental movement of the wheel 
frames within the leg. The support bars 240 have a jack connector 242 on 
its outermost end. A wheel axle support bracket 244 is attached to each 
bar 240 and rotatably supports axle 246 associated with one of the wheels 
110 and 112. 
Some form of braking system is generally provided to prohibit the unit from 
moving when the boom extended. One form is a wheel rotation prohibiting 
mechanism 248 is provided for each wheel. This wheel rotation prohibiting 
mechanism 248 as shown in more detail in FIGS. 15-16 includes a main bar 
250 rotatably positioned in a sleeve 252 affixed to support bar 240 where 
a leverage bar 254 extends obliquely from the main bar. A locking bar 256 
is attached to the main bar 250 and is pivotally movable into a wheel 
locking position where rotation of the wheel is blocked as the locking bar 
is pinned against the wheel. Another form is a braking mechanism within 
the actual rim of the wheel such as a drum braking system and this may 
optionally be placed on every wheel or just the steering or pivot wheel or 
wheels. 
As to front wheel frames 114 and 116 as best shown in FIGS. 2-3, 5 and 10, 
each includes a support bar 260 of a complementary yet smaller cross 
section than leg 190 so as to be slidable within the leg where both of bar 
260 and support 190 include a plurality of holes in which a lock pin 261 
is insertable once proper positioning is achieved so as to prevent 
accidental movement of the wheel frames within the legs. The support bars 
260 have a hole therein for receiving a pivotal vertical axle 262 for 
allowing turning of the wheels 118 or 120. This vertical axle 262 is 
affixed to a bracket 264 of bend nature that bends around to align with a 
horizontal axle 266 of the wheel 118 or 120 where the substantially 
horizontal axle is pivotal in the bracket. 
In the case of either support bar 240 or 260, the complementary cross 
section requirement need not be of identical shape. For instance, the legs 
152, 154, and 190 may be of a square or rectangular shape and the bars 240 
or 260 of a similar square shape. Alternatively, the legs 152, 154, and 
190 may of a square shape while the support bars 240 or 260 are of a round 
shape so as to selectively rotatable within the legs 150, 152 and 190 
since pins secure the bar from rotation within the legs but rotation may 
be beneficial during axial adjustment in and out, or should jacks or other 
support be used thereby allowing the wheels to be pivoted out of the way. 
This is particularly useful on the support bars 260 since a round 
configuration allows the wheels 118 and 120 to be pivoted out of the way 
as is desirable in certain circumstances such as where an operator desires 
to tow the lift mechanism 100 using only the back wheels 110 and 112 with 
the hinge 174 locked. When this round extendible and retractable support 
bars, extensions, outriggers, etc. design, such as round extensions 260, 
is used with square legs, such as leg or axle 190, then often nubs are 
attached to the round extension to assist in preventing rotation when the 
extension is retracted while such nubs are positioned such that almost 
complete extension allows for nub removal from the leg or axle and thus 
rotation thereof. 
Another embodiment includes the manufacture of the support bars 260 on the 
front wheels such that its inner portion is round while its outer portion 
is square (for instance, a round section may be welded to a square section 
where each is of a cross section that fits within the leg or axle 190). 
The square section would most likely be a majority of the extension or 
support bar 260 thereby prohibiting rotation over almost the entire 
extending whereby the round section would be a small portion of the 
innermost part of the bar such that the bar need not be removed to be 
rotated (dust almost fully extended). 
Alternatively, all of the framing, legs, axles, bars, outriggers, 
extensions, etc. which are shown in the Figures as being of a square or 
rectangular construction could be of a round or other geometric 
construction. 
A tool or other object storage chamber 280 may be provided as is shown in 
the figures. It may include a door, etc. This tool chamber 280 is 
interchangeable in position with the power supply 128 as needed. A 
platform could also alternatively be provided in place of the tool box. 
A T-handle 290 may also be provided for a number of purposes including: (1) 
for use in moving the lift mechanism 100 when it is not attached via 
tongue 170 to a vehicle, (2) for use in steering the lift mechanism 100, 
(3) for use in braking the lift mechanism by acting as a wedge or similar 
stop, and (4) for use as a lever to lift rear wheels to allow the 
outriggers on the rear wheels to be extended. The T-handle is selectively 
removable from a slot 292 in the tongue. Additional slots may be placed on 
the tongue or at other locations for receiving the T-handle for use in 
moving the lift mechanism or for storage of the T-handle. When the 
T-handle is placed in the slot 290, the lift mechanism 100 may be steered, 
pulled or pushed. 
As stated above, the T-handle is useful as a stop or brake as well as a 
lift for the lift mechanism as the T-handle includes a latch 291 that may 
selectively be wedged under a block 293 on the frame or seated over a pin 
295 on the frame. Specifically, latch 291 may be wedged under block 293 
with the T-handle pinned against the ground at an angle such that movement 
of the lift mechanism 100 in that same direction is not possible as the 
weight of the lift mechanism will stop such motion by the T-handle being 
urged against the ground. As to the latch 291 used to assist in lifting 
the lift mechanism, one of the pins 295 is seated within the latch 291 
with the T-handle at a slight angle whereby the T-handle is then pivoted 
so as to lift the leg, outrigger, extension, etc. that the pin is on. This 
is particularly useful when extension or retraction of one of the wheel 
frames, and particularly the rear wheel frames 106 and 108 is desired as 
the T-handle lifts the leg 150 or 152 and te respective wheel frame 106 or 
108 is thus lifted off of the ground and the retractions or extension may 
occur. 
The tongue 170 as described above has a hinge 174 therein. The hinge is 
selectively lockable to be rigid or unlockable so as to hingedly flex for 
pivoting upward out of the way or for flexing during towing. As described 
above, this locking is performed by sliding of a rigid bar within the 
hinge whereby pivoting is selectively prohibited. 
All of the pins 219, 241 and 261 are load bearing pins that lock within the 
hole each is inserted into by any of several methods including radial keys 
inserted through the pin to prohibit its removal. These pins are typically 
attached via chain, wire or other means to the adjacent parts such as to 
the boom, frame, legs, support bars, etc. whereby preferably each pin has 
a loop at its exposed end with a chain attached thereto that is connected 
to a ring about is other end that is affixed to the boom. Each pin may 
also have a head or collar to prevent complete insertion of the pin into 
its respective hole, or to support the pin when placed in a holder or 
other ring like receiver for storing the pin when not in use where the 
holder is attached to the boom. Each pin may also include a small hole in 
the end opposite the collar where the hole is for receiving a cotter key 
or pin, or like device for securing the pin within a hole by blocking its 
removal. 
Once the pins are properly locked in after the support bars 240 and 260, 
and the boom sections 204-208 are properly extended or retracted (and 
typically the boom angle is chosen), then an object may be lifted by the 
lift mechanism where the object is hooked on to hook 217. Tilt indicator 
134, as is best shown in FIGS. 17-20, indicates tilt of the lift mechanism 
100 as the frames 102 and 104 flex and move in relation to one another and 
as leg 190 flexes and moves from end to end. Tilt indicator 134 includes a 
bar 300, a fastener 302 for pivotally fastening the bar 300 to one of the 
frames 102 or 104, and a connector 304 for connecting a portion of the bar 
spaced apart from fastener to the other of the frames 104 or 102, 
respectively. In operation, as the frames converge or diverge the pivotal 
bar 300 pivots since the connector is secured to the other of the frames. 
In one embodiment, the bar 300 is attached to a hook 306 and includes a 
weighted plate 308, a sleeve 310, and a main body 312 with a curled end 
314. The connector 304 is a chain linked to the body 312 at one end and 
the hook 306 at the other end. As is shown, when too much weight is on the 
boom or the boom is extended too far or at the wrong angle for the weight, 
the first frame 102 begins to lift at the tower end thereby lifting chain 
306 which pulls or pivots the tilt indicator 134 upward thereby showing 
unsafe tilt. 
Other optional or standard features that may be incorporated into the lift 
mechanism 100 include the following. In the described and shown 
embodiment, the boom is manually telescoping; however, the boom is readily 
adapted to hydraulic or other automatic telescoping. In this scenario, 
each of the boom sections 204-208 is actuatable by a drive mechanism, such 
as a hydraulic actuator or electric motor for instance. 
The tilt indicator 134 may also be electrically or otherwise connected to a 
light or other visual indicia that illuminates or otherwise indicates 
tilting when the tilt indicator reaches a certain predefined tilt 
measurement. In addition or alternatively, the tilt indicator 134 may also 
be electrically or otherwise connected to a buzzer, alarm or other audio 
indicia that emits an audible sound or otherwise audibly indicates tilting 
when the tilt indicator reaches a certain predefined tilt measurement. 
Furthermore, the tilt indicator 134 may also be electronically connected 
to the boom angle actuator 124, the winch 130, and any other motor or 
drive mechanism whereby when a preset tilt limit is exceeded, a switch 
shuts off the boom angle actuator, winch or other motor or drive 
mechanism. 
The lift mechanism 100 may also include bubble levels on one, some or all 
of the first and second frames 102 and 104, and the legs, leg extensions, 
supports, outriggers, axles, etc. including 150, 152, 190, 240, and 260. 
This bubble level or other leveling device is useful for assisting the 
user in positioning the lift mechanism on level ground, adjusting the lift 
mechanism using jacks, or merely having knowledge of how level or unlevel 
the lift mechanism is. 
In addition, the lift mechanism 100 may also include various other leveling 
device including one or more mercury switches for the monitoring of side 
to side balance of the lift mechanism. This mercury switch may be 
connected to a switch or other similar mechanism whereby when a 
preselected side to side tilt is reached, the switch shuts off the boom 
angle actuator, winch, or other motor or drive mechanism. 
The lift mechanism 100 may also include an angle indicator on the boom for 
indicating the angle of the boom in relation to the ground on which the 
lift mechanism sets, or alternatively in relation to a horizontal 
imaginary plane. 
The lift mechanism 100 may also include a power drive motor attached to one 
or more of the wheels for maneuvering or driving the vehicle as needed to 
properly position the vehicle or move the vehicle in a restricted area. 
The lift mechanism is not only portable and towable as described above, it 
is movable by generally only one person as it is relatively lightweight. 
The lift mechanism is also easy to disassemble should it be desirable to 
load it into a truck, or move it to a location that is otherwise not 
attainable by rolling or driving it. For example, this lift mechanism can 
be disassembled, carried piece by piece inside of a building, and 
reassembled therein. Also, such disassembly, moving, and reassembly can 
occur to put the lift mechanism in an otherwise tight, hard to reach, 
constrained, confined, etc. spot. The disassembly merely requires the 
removal of pins 196 and 200 whereby the boom is removable from the frames 
102 and 104 which are in turn removable from each other. The lift 
mechanism is now in much smaller and lighter pieces that are readily 
movable by one person, even through doorways, etc. The actuator may also 
be removed from the boom by removing the pin at the other end of the 
actuator thereby turning the two bolt disassembly into a three bolt 
disassembly. 
Should more compact legs be desired, the lift mechanism is alternatively 
designable to include multiple telescoping legs, outriggers, etc. The 
embodiment shown displays legs, axles, etc. 150, 152, and 190 with one 
extension, outrigger, etc. retracting and extending therefrom (namely 240 
and 260); however, multiple extensions or outriggers, etc. could 
telescopically extend and retract from the legs and axles in a manner 
similar to theat of boom 122. 
Various safety switches are optionally available for the lift mechanism 
100, some of which have previously been described. One safety switch that 
is available on the lift mechanism 100 is affixed or generally located on 
the first frame 102 while a plate or other surface for interacting with 
the switch is generally located on the second frame 104 whereby separation 
of the frames disconnects the plate from the switch thereby shutting down 
the actuators, motors and drives. One such application is to attached such 
a switch either in or on the battery box 128 about its bottom surface 
while providing such a plate or surface on the front wheel axle 190 
whereby when tilting of the lift mechanism occurs, the battery box on the 
first frame 102 lifts away from the axle thereby deactivating the boom 
angle actuator 124, winch 130, etc. 
The battery or batteries of the system within box 128 may be of any known 
type and number. For instance, the system may be designed to use two "6 
volt" batteries, or two "12 volt" batteries, etc. 
Winch 130 may be any type of lifting device such as a standard winch, 
hoist, or other mechanism capable of imparting lifting upon an object. The 
winch or hoist can be electric, hydraulic or of any other nature. In one 
version, the winch is a 2,000 pound hydraulic winch which eliminates the 
need for a snatch block 132. 
One example of a specific embodiment of the above described lift mechanism 
100 includes the boom 122 being capable of angular motion from 
approximately 5.degree. to 10.degree. below horizontal to almost vertical 
at approximately 75.degree. to 80.degree. above horizontal. The boom when 
fully retracted is of approximately 6 feet to 8 feet (and preferably 
approximately 7 feet to 71/2 feet) in length while being of approximately 
20 feet to 35 feet (and preferably 25 feet to 32 feet) in length when 
fully extended using the main boom section 204 and four extensions 205-208 
(or alternatively a lesser number such as three that are each of a longer 
design). 
These are boom lengths whereby the object is liftable above the floor the 
lift mechanism sits on a distance greater than these lengths and 
preferably approximately 28 feet. 
In this one embodiment, the support arms 240 extend from and retract into 
the legs 150 and 152 from a fully retracted position of approximately 6 
feet to 10 feet (and preferably approximately 8 feet) to a fully extended 
position of approximately from 8 feet to 12 feet (and preferably 
approximately 10 feet or slightly more). The support arms 260 extend from 
and retract into the leg 190 from a fully retracted position of 
approximately 3 feet to 5 feet (and preferably approximately 4 feet or 
slightly less) to a fully extended position of approximately from 5 feet 
to 8 feet (and preferably approximately 5 feet or slightly more). 
In this same embodiment, the loads that may be lifted by the lift mechanism 
100 range up to a maximum of 2,000 lbs. while still meeting all necessary 
safety factors and requirements. Safety factors for the overall unit range 
from a minimum of 1.25 to up to and beyond 7. The actual safe load lifting 
maximums are given by way of example as follows: at a 75.degree. angle as 
is show by boom D, 810 lbs. lifted to approximately 28 feet in height, 920 
lbs. lifted to approximately 24 feet in height, 1450 lbs. lifted 
approximately 18 feet in height, and 1500 lbs. lifted to approximately 15 
feet in height, and 2000 lbs. lifted to approximately 10 feet in height; 
at a 60.degree. angle as is show by boom C, 480 lbs. lifted to 
approximately 22 feet in height, 750 lbs. lifted to approximately 18 feet 
in height, and 1500 lbs. lifted to approximately 14 feet in height; and at 
a 45.degree. angle as is show by boom B, 530 lbs. lifted to approximately 
15 feet in height, and 1270 lbs. lifted to approximately 12 feet in 
height. 
In an alternative embodiment, the extensions 114 and 116, and the wheels 
118 and 120 as well as the handle 290 are replaced by an improved steering 
mechanism 400 as is shown in FIGS. 26-30D. The improved steering mechanism 
400 includes a modified tongue 170'. In this embodiment, the tongue 170' 
is not attached to the vertical tower or mast 162 and is instead connected 
to pivot arms 192 and 194 so as to move with second frame 104 as the 
wheels 118 and 120 do in the above described embodiment. The modified 
tongue 170' pivots and when pivoted to its upward maximum contacts with 
the mast 162 as is shown in the FIG. 26. The modified tongue 170' freely 
pivots downward away from the mast although as described above, the tilt 
indicator 300 serves to prohibit too much tilting by the first frame 102. 
The modified tongue 170' includes a tongue mounting fork 400 as best shown 
in FIGS. 27A, 27B, 27C and 27D, a caster mounting bracket 402 as best 
shown in FIGS. 28A, 28B, 28C and 28D, a slug 404 as best shown in FIGS. 
29A and 29B, and a tongue assembly 406 with a hinge 408 thereon as best 
shown in FIGS. 30A, 30B, 30C and 30D. 
Tongue mounting fork 400 includes a receiver tube 410 with an open end 411 
and a closed end 412. The fork 400 further includes a pair of tines or 
plates 413 extending diagonally therefrom as best shown in FIG. 27A and 
27B. These tines 413 extend around the mast 162 and attach to pivot 
connectors 196 as shown in the embodiment of FIGS. 1-25. 
Caster mounting bracket 402 includes a tubular end 420 and a square or 
rectangular end 421 with a mounting plate 422 thereon. The end 421 further 
includes a pair of tubes 422 and 423 tangentially mounted perpendicularly 
to the axis of the bracket as shown in FIGS. 28A-28D. One of these tubes 
serves as the pivot axis to the hinge 408. 
Slug 404 is an elongated square or rectangular tube that corresponds in 
shape to end 421 and is of a size so as to be seatable therein. Various 
holes are drilled in slug 404 to correspond with holes in end 421 such 
that a pin may be insertable therein to hold slug 404 within end 421. 
Various other holes serve to allow for pinned connection of the tongue 
assembly 406 over the slug 404 so as to prohibit its hinged movement when 
the tongue assembly is fully inserted. 
Tongue assembly 406 includes hinge body 408, connection tube 440 which is 
of the same cross sectional shape as the slug but a slightly larger 
dimension so as to fit over it, and an actual hitch portion 178' with a 
hitch socket 180' therein. The hinge body 408 is pivotable about a pin 
inserted through both the hinge body 408 and one of the tubes 422 and 423. 
The tongue assembly 406 when fully inserted is rigid with the slug 404 and 
caster mounting bracket 402; however, the tongue assembly 406 may be 
removed from the slug whereby the hinge 408 allows for its pivotable 
movement out of the way. In this manner, a rigid tongue is provided for 
during towing, while it is removable or pivotable out of the way when not 
needed. A handle such as 290 is no longer needed as the tongue assembly 
when pivoted upward may function in the same capacity. 
A caster assembly 450 is available for connection to mounting plate 422. It 
includes a mount 452, a race and bearing assembly 454, a rigid main 
support 456, an axle 458 and a pair of casters 460 on each of the axle. 
The race allows for pivotal movement of the assembly 450 as needed. The 
assembly 450 allows for pivoting of the entire lift mechanism 100. 
It is also an option to move the jack connectors 242 from the extensions 
106 and 108 to the legs 150 and 152. This allows some models of the lift 
mechanism to have wheels 110 and 112 attached to the legs rather than 
extensions. 
Accordingly, the lift mechanism is simplified, provides an effective, safe, 
inexpensive, and efficient device which achieves all the enumerated 
objectives, provides for eliminating difficulties encountered with prior 
devices, and solves problems and obtains new results in the art. 
In the foregoing description, certain terms have been used for brevity, 
clearness and understanding; but no unnecessary limitations are to be 
implied therefrom beyond the requirement of the prior art, because such 
terms are used for descriptive purposes and are intended to be broadly 
construed. 
Moreover, the description and illustration of the invention is by way of 
example, and the scope of the invention is not limited to the exact 
details shown or described. 
Having now described the features, discoveries and principles of the 
invention, the manner in which the improved lift mechanism is constructed 
and used, the characteristics of the construction, and the advantageous, 
new and useful results obtained; the new and useful structures, devices, 
elements, arrangements, parts and combinations, are set forth in the 
appended claims.