Heavy duty crane

A crane is operable in either a regular mode or a heavy duty mode. In the regular mode, an upper works is rotatble, through a turntable bearing, on a lower works. A boom is pivotally connected to one end of the upper works and a counterweight is connected to the opposite end thereof. In the heavy duty mode, a support ring surrounds the lower works and is connected thereto. An auxiliary frame is mounted on the support ring, surrounding the upper works, for rotation on the ring in unison with rotation of the upper works. The boom used in the regular mode is pivotally connected to the auxiliary frame for use as a gantry, and a heavier boom is pivotally connected to the auxiliary frame adjacent the gantry. The counterweight of the machine in the regular mode is shifted to the auxiliary frame opposite the boom and gantry, and an auxiliary counterweight is added to the auxiliary frame.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to cranes, and, more particularly, to heavy 
duty cranes for lifting heavy loads. 
A conventional crane has a lower works, and an upper works which is 
mounted, through a turntable bearing, for rotation on the lower works. A 
boom is pivotally connected to one end of the upper works, and a 
counterweight is secured to the other end of the upper works. In this type 
of crane, the weight of the load, and the weight of the counterweight, 
must be transmitted to the lower works (and the ground) through the 
turntable bearing. Consequently, the load which can be lifted by the crane 
is limited to a load which can be supported by the upper works without 
damage to the turntable bearing, and/or without exceeding a safe margin on 
overturning. 
2. Description of the Prior Art 
Many efforts have been made in the past to transfer the load carried by the 
boom, and/or the weight of the counterweight, around (instead of through) 
the turntable bearing. 
The United States patent to Holt No. 1,159,841 shows an upper works (or 
swing frame) rotatably mounted on a lower works (or main frame). A boom is 
mounted at one end of the upper works, and a heavy prime mover (which acts 
to counterbalance the load) is mounted at the other end of the upper 
works. A pair of slide blocks is mounted under the prime mover, between 
the upper works and the lower works to partially support the load imposed 
on the upper works and transfer that load to the lower works. 
The United States patent to Scheuerpflug No. 2,910,189 shows an upper works 
mounted for rotation on a lower works. A boom is pivotally mounted on an 
intermediate member which, in turn, is pivotally connected to the upper 
works. The intermediate member rolls on a way on the lower works to 
transmit the load of the boom directly to the lower works (and around the 
upper works). 
The Netherlands Pat. No. 6,405,689 shows an upper works mounted on a lower 
works wherein the boom is mounted on a separate wheeled vehicle for 
transmission of the load directly to the ground. 
The United States patent to Beduhn No. 3,485,383 shows a crane with an 
upper works mounted for rotation on a lower works. An auxiliary support 
ring mounted on the ground surrounds the lower works, and supports one end 
of a carrier which is pivotally connected to the upper works. A boom is 
mounted on the end of the carrier supported by the ring to transfer the 
load of the boom through the support ring to the ground. The machine has 
two counterweights, one permanently mounted on the upper works and one 
slidably mounted on the upper works but supported by the support ring. 
SUMMARY OF THE PRESENT INVENTION 
In the machine of the present invention, a counterbalanced auxiliary frame 
has been provided to transfer the weight of the load and the counterweight 
to the ground without transmission through the turntable bearing. 
In the machine of the present invention, an upper works is rotatably 
mounted, through a turntable bearing, on a lower works. The upper works, 
the turntable bearing, and the lower works may be used as a regular duty 
crane. In addition, however, when large loads must be lifted, a circular 
support is mounted on the ground to encircle the lower works. The 
counterbalanced auxiliary frame is mounted on the circular support for 
rotation thereon in unison with rotation of the upper works. The 
counterbalancing forces on the auxiliary frame comprise the boom, 
pivotally connected to one end, and an auxiliary counterweight mounted at 
the opposite end. The upper works has a counterweight which is used when 
the crane is operated as a regular duty crane, but when heavier loads are 
to be lifted, the upper works counterweight may, in one form of the 
invention, be transferred to the auxiliary frame to assist the auxiliary 
counterweight in counterbalancing the weight of the load carried by the 
boom. The full weight of the counterbalanced auxiliary frame (that is, the 
weight of the auxiliary frame itself, the weight of the boom and the load 
carried thereby, and the weight of the auxiliary counterweight and/or the 
upper works counterweight) is transferred directly to the ground without 
imposing the load on the turntable bearing. 
In the mechanism of the present invention, the auxiliary counterweight need 
not be mounted directly over the circular support, but can instead be 
positioned in any desired position (relative to the circular support) 
opposite the boom to create the desired counterbalance for the boom (and 
the design load to be carried thereby). 
It is therefore one object of the present invention to provide a crane 
capable of heavy duty lifting in which the load is carried by a 
counterbalanced auxiliary frame. 
It is another object of the present invention to provide a crane in which 
the force of the load and the gravitational force of the counterweights is 
transferred through a counterbalanced auxiliary frame directly to the 
ground and not through the turntable bearing. 
It is yet another object of the present invention to provide a crane in 
which the gravitational force of all counterweights can be transferred 
from the upper works turntable bearing to a counterbalanced auxiliary 
frame.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The heavy duty crane of the present invention is made up of an assembly of 
parts (to be described hereafter), some of which correspond in function to 
parts of a conventional, regular duty crane. These parts which correspond 
in function to parts of a regular duty crane may be assembled as a crane 
for regular duty, as shown in FIGS. 1 and 2. In FIG. 1, parts have been 
omitted for clarity. 
The regular duty crane of FIGS. 1 and 2, identified by the numeral 20, 
includes a lower works 22 with a central base portion 24 and a pair of 
side frames 26 connected, respectively, to the sides of the base portion. 
A pair of sprockets 28 and 30 are rotatably mounted at the ends of the 
side frame to receive an endless track 32. 
A bearing 34 is received in the central base portion 24 to support the 
upper works 36 of the crane for rotation about a vertical axis A with 
respect to the lower works. The upper works has brackets 38 at the forward 
end to receive a boom 39 (see FIG. 2), and has a plate 40 at the rear end 
to receive counterweights 42 and 44. The plate 40 can be moved up against 
a rear platform 46 of the upper works by a power lift mechanism 48 mounted 
on platform 46. 
The mechanism 48, as shown in FIGS. 3 and 4, includes a pair of arms 50, 
pivotally connected to the upper works at 52, to extend over platform 46. 
A cross bar 54 extends between the ends of arms 50 and receives thereon a 
bracket 56. A ram 58 is pivotally connected at one end to upper works 
platform 46 and has a piston rod pivotally connected at the opposite end 
to bracket 56. Thus, as the ram expands, the arms 50 swing upwardly to the 
position shown in FIGS. 3 and 4, and as the ram contracts, the arms 50 
swing downwardly. 
A telescopic strut 61 is connected between the outer end of each arm 50 and 
the upper works platform 46 to support the arms in a selected position. 
The lower portion 61a of the strut has a series of holes 62 into one of 
which a pin 63 is received, passing through a hole in the upper portion 
61b of the strut, to lock the arms in a predetermined position. 
A foldable leg 64 is connected at the upper end to bracket 56 and at the 
lower end to plate 40. When the arms 50 are in their uppermost position, 
the plate 40 (on which counterweights 42 and 44 are mounted) is moved up 
against the underside of upper works platform 46. Links 65, secured at 66 
to the plate 40, are pinned at 67 to the platform 46 to lock the plate 40 
to the underside of the platform 46. After the counterweight plate is 
locked to the upper works, the leg 64 can be folded and the arms 50 
lowered until the mechanism 48 is required to shift the upper works 
counterweights off the upper works for heavy duty loads. 
The heavy duty crane 69 of the present invention is shown in FIG. 5. For 
illustrative purposes, all parts of the regular duty crane 20 of FIG. 1 
will be incorporated in the heavy duty crane of FIG. 5, and these parts 
will be identified in the drawing figures of the heavy duty crane by prime 
numerals corresponding to the numerals by which these parts were 
identified in the regular duty crane. Parts which are used only in the 
heavy duty crane will be identified by their own numerals, without any 
prime. 
The heavy duty crane is shown in FIGS. 5 to 10. Many of these figures show 
only portions of the crane, solely for a better understanding of those 
portions of the crane which would not be clearly visible if the whole 
crane were shown in every figure. The particular subassemblies shown in 
each figure were selected only to show clearly the construction of the 
crane, and it is not intended that these subassemblies illustrate a 
preferred method of assembling the crane. 
A ring 70 (preferably a box section to resist movement), having a flat 
upper surface 72, surrounds the lower works 22' of the crane as shown in 
FIG. 6. The ring is supported from the ground by adjustable standards 74 
to lie in a generally horizontal plane. The ring 70 is securely connected 
to the lower works 22' by means of two trusses 76, 78, each of which is 
connected between the central base portion 24' of the lower works and 
bosses 80 extending inwardly from the inner surface of the ring. Each end 
of each truss is connected at each side to the central base portion 24' of 
the lower works, and a boss 80, by means of an upper and lower clevis 82, 
84, in conjunction with an upper and lower ear 86, 88 and horizontal pins 
90. Thus, the ring 70 is held securely against rotation or pivoting 
movement (or horizontal movement) relative to the lower works 22'. 
As shown in FIG. 7, a rectangular, auxiliary frame 92, consists of a 
forward portion 92a, a central portion 92b, and a rear portion 92c. The 
frame, as a unit, can be considered as having two parallel side members 
93a, 93b, a front member 93c and a rear member 93d. The front and rear 
portions 92a and 92c are secured to central portion 92b as at 94, by 
intermeshing ears, on the top and bottom of the frame, and a horizontal 
pin through the ears to hold the portions together without significant 
pivotal motion, to form an unarticulated frame. 
The auxiliary frame 92 has depending rollers 96, aligned tangentially with 
ring 70, which ride, at four points, on the upper surface 72 of the ring. 
At the rear of the auxiliary frame, there are two inwardly extending 
support arms 98a, 98b, and a support pad 98c (see FIG. 8) connected to 
cross beam 100. The arms 98a, 98b and pad 98c define a support shelf 98, 
the purpose of which will be described hereinafter. At the front of the 
auxiliary frame there is a truss 102, connected between the side members 
of the frame, with a fitting 104 extending inwardly therefrom. The fitting 
104, for reasons which will become clear hereinafter, has four spaced 
fingers 105 to straddle a portion of truss 102 and also the vertical pin 
103. The spacing of the fingers is such as to allow a small vertical 
movement between the fitting 104 and the truss 102. 
As shown best in FIG. 8, the upper works 36' is received in the bearing 34' 
of the central base portion of the lower works 22 for rotation about the 
axis A'. Conventional power machinery, not shown, is provided to rotate 
the upper works with respect to the lower works. The auxiliary frame 92, 
which surrounds the upper works, is connected to the upper works, at the 
front and rear of the upper works, for rotation with the upper works. The 
axis A' of rotation of the upper works passes through the center of the 
ring 70, and the rollers 96 of the frame 92 are equi-spaced from the axis 
A', so that the auxiliary frame can rotate on the ring 70 through any 
angle the upper works is rotated. The frame 92 is connected to the forward 
end of the upper works through fitting 104, which has extending arms 104a, 
104b received between ears 106 for pinning as at 108. The ears 106 are 
spaced apart sufficiently to allow a small amount of free vertical 
movement between the fitting 104 and the upper works. The rear end of the 
upper works 36' is connected to frame 92 by means of plate 110 which is 
received between the horizontally aligned ears 111 on these members and 
pinned as at 112. Again, the ears 111 are spaced apart sufficiently to 
allow a small free vertical movement between the plate 110 and the members 
to which it is connected. Thus, the upper works 36', and the auxiliary 
frame 92, rotate about axis A' in unison. Although the fitting 104 and 
plate 110 serve to connect the upper works 36' to the auxiliary frame 92 
for the transmission of torque from the former to the latter without any 
play in a lateral direction between these members, there is sufficient 
vertical play at the connection of the fitting 104 and the plate 110 to 
these members to allow some small free vertical movement between the frame 
92 and the upper works 36'. 
Although the amount of vertical relative movement between the auxiliary 
frame 92 and the upper works 36' is small, it is important because it 
allows all the weight of the frame, and all the weight carried by the 
frame, to be transmitted directly to the ring 70 (and thence to the 
ground) without imposing any load on the upper works 36' or the bearing 
34'. 
As shown best in FIG. 9, four auxiliary counterweight units 114 are mounted 
on the rear portion 92c of the auxiliary frame 92. The upper works 
counterweights 42' and 44' are mounted on plate 40' (see plate 40 of FIG. 
1) which lies between the shelf 98 (defined by arms 98a, 98b and pad 98c) 
and the connecting plate 110. When the counterweights 42', 44' and plate 
40' are used in the heavy duty mode, the plate 40' is lowered by the 
mechanism 48' from abutment against the underside of shelf 46' (of the 
upper works) to a position on shelf 98 (FIG. 8) where the entire weight of 
plate 40' and the counterweights 42', 44' is borne by the auxiliary frame. 
Thus, when the crane is used in the heavy duty mode, not only do the 
auxiliary counterweight units 114 lie directly on auxiliary frame 92, but 
also the regular counterweights 42', 44' and plate 40 as well. 
The superstructure and rigging of the crane of FIG. 1 is shown in FIG. 2. 
The crane, when utilized for regular duty, has a boom 39 pivotally 
connected to brackets 38 at the front end of the upper works. A live mast 
132 is pivotally connected to brackets 134 adjacent the brackets 38 on the 
upper works. A boom stop 136, to limit the rearward movement of the boom, 
is mounted on the upper works. Boom pendants 138 are secured at one end to 
the top of the boom 39 and at the other end to the top of the live mast 
132. Boom hoist reeving 140 between the top of the live mast and the top 
of the upper works, when powered by a winch in the upper works, swings the 
live mast to raise the boom. A hoist, or load, line 146 has one end 
connected to a winch 148 in the upper works. The line passes over a sheave 
150 at the top of the boom to a sheave block 152 having a load hook 154. 
The line 146 runs around the sheave in a block 152 and is secured to the 
top of the boom. A housing 142 for the upper works protects the machinery 
thereon and provides a cab 144 for the operator. 
The superstructure and rigging for the crane when in the heavy duty mode is 
shown in FIGS. 5 and 10. In this mode of operation, a large boom 156 is 
pivotally connected to ears 158 on the forward end 92a of the auxiliary 
frame 92. A gantry 39' (which may be the boom 39 of the machine when used 
in the regular duty mode) is pivotally connected to ears 160 adjacent ears 
158 on the frame 92. 
The gantry 39' is held tightly against boom stop 162 (which is pivotally 
connected to the top of the upper works of the crane) by gantry pendants 
164 connected between the top of the gantry and the top of the live mast 
165, which is anchored to the auxiliary frame by lines 167. Boom hoist 
reeving 166 extends between the top of the boom 156 and the top of the 
gantry 39', and includes sheaves 168 and 170. A boom hoist line 172, which 
has one end connected to a winch 174 in the upper works, is received over 
the sheaves 168 and 170 and has the opposite end connected to the sheave 
168. Operation of winch 174 permits the boom 156 to be lowered, and 
enables the boom to be raised to any desired position, including the 
extreme upper position shown in FIG. 5. A load, or hoist, line 176 has one 
end connected to winch 178 and has the opposite end secured to the top of 
boom 156. The line is received over a guide sheave 180 on gantry 39', a 
sheave 182 on the top of gantry 39', a sheave 184 on the top of boom 156, 
and a sheave in sheave block 186. A hook 188 is suspended from block 186 
to receive the load. 
Although the best mode contemplated for carrying out the present invention 
has been herein shown and described, it will be apparent that modification 
and variation may be made without departing from what is regarded to be 
the subject matter of the invention.