Note: Descriptions are shown in the official language in which they were submitted.
W~3/2000S PCI`/US92/02649
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SWING LOCR M~rHANTt M FOR
Cu~ ~uc ~lON ~s~u~ WITH ROTATABLE UPPER WoRRS
BACXGROUND OF '~ INVEN~ION
The present invention relates to construction
equipment, such as cranes, having an upper works
rotatably mounted on a lower works, and more
particularly to a swing lock -- ` AniF~ for use on such
construction equipment.
Construction equipment, such as cranes or
excavators, often must be moved from one job site to
another. Moving a crane or excavator can be a
formidable task when the machine is large and heavy.
For example, highway limits on vehicle-axle loads must
be obGerved and overhead obstacles can dictate long,
inconvenient routings to a job site.
One solution to improving the mobility of
large construction r-^hint~c is to ,lic~- cttmhle them into
sDaller, more easily handled , - Ls. For example,
the upper rotating structure of a crane with a large-
diameter, swing bearing can be removed from the mobile
lower works. Because most swing bearings have at least
one bolted interf ace, the machine can be taken down
into more manageable sections for transport.
The A;F~A~St~mh1Y of a crane with a
conventional bearing having an inner race and an outer
race is both labor-intensive and tir~ suming, making
it a costly undertaking. The disassembly of numerous
WO 93/2000~ 2 1 0 9 9 3 9 - 2 - PCI/US92/026~
high-strength f asteners is one f actor that impedes
rapid l~n~lP~ ;n~ Of r-ch;nPc. As an example, a 200-ton
lifting crane with a 100-in. (pitch-diameter) swing
bearing may have 70 or more bolts in one or both
bearing rings. To disconnect and reassemble the
bearing, all the bolts in one of the bearing rings must
be disassembled, replaced, and uniformly torqued to a
high preload.
Machine ~ CACS~ 'ly can cause alignment
difficulties as well. For instance, the bearing bolt
holes must be aligned precisely with mounting-surface
holes in the reassembly of a machine. Because the
machine parts are large and heavy, such alignments can
be unwieldy and ti ~ ...inq. Moreover, if the dis-
connect is made at the outer bearing ring (most often
the ring f ixed to the machine rotating structure), then
the cwing bearing drive also must be critically aligned
during machine assembly to minimize ha~ l ACh and
attendant shock loading from slewing motion.
Many prior art devices have the disadvantages
that they are expensive. Also, the configurations are
seldom interchangeable with standard bearings.
~urther, in many cranes, the upper works is the
heaviest part of the ~1icAcspmhled crane, and is there-
fore the limiting element in the transportability of
the crane . Thus, a quick tl i cer~nnp~t system should
pref erably not add weight to the upper works .
Cranes that have a 6wing bearing, whether
easily ~li cconn-~rtable or not, typically also include a
swing lock --hAn; ~ to prevent rotation about the
swing bearing except when under operator control. Some
swing lock - AniQmc, however, can engagQ during crane
operation if there is an accidental loss of power to
the swing lock - -ni m. If this occurs during a
swing maneuver, damage to the crane and other possible
injury can result. Other swing lock ---hAni-mc do not
have certain desirable features. For instance, it is
~20005 PC[~US92~02649
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often desirable to allow a crane to "weather vane" when
not in operation to reduce wind-imposed loads on the
crane. If the swing lock is not designed to allow
disengagement when the crane ifi shut down, the crane
will remain locked in one position and changing wind
direction will impose greater 6ide loads than desired.
STTMMARY OF THF~ INVT~NTION
A swing lock r- ~ 9nio~ for a piece of
construction equipment with an upper works rotatably
supported on a lower works has been invented which
.IVt:LI_ -- the deficiencies noted above and has other
advantages. The - ' -n;~m is primarily for use with
conventional swing bearings having an inner race and an
outer race. The - ` ~nicn~ may be used with a quick
.sicconnF~ct system where a cranes upper works sits on an
adapter plate and is releasably connected to the
adapter plate by links pinned at their upper end to the
body of the upper works . The swing lock ~ n i ~r of
the present invention is then supported on the
underside of the adapter plate.
The quick disconnect system utilizes links
and j acking bolts to hold the upper works and adaptor
plate together. A jacking bolt at the lower end of the
link bears against the underside of the adaptor plate.
The bearing outer race is secured to the bottom surf ace
of the adapter plate. The bearing inner race is
secured to the crane lower works, as in a conventional
crane . When the crane is to be separated, the j acking
bolt is loosened to allow the links to swing free of
the adaptor plate. The upper works is then easily
separated from the lower works. The adapter plate and
bearing stay attached to the lower works. All of the
bolts used to hold the bearing races are left intact
and thus do not need to be retorqued when the crane is
reassembled .
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The swing lock --hAn; r~ includes a swing
lock segment with teeth adopted to intermesh with the
gear teeth on the swing bearing. A piston is used to
engage and /1 i ~AnqAqe the swing lock segment . In
addition, the swing lock -- Anir-n includes a connector
link connected to the swing lock segment that has a
f oot on one end adapted to f it into a hole in a rigid
portion of the swing lock - - ~n i r-n to provide rigid
contact with the gear teeth and prevent the swing lock
segment from disengaging.
In a preferred ~mho~lir ~, the swing lock
r--hAn;-:m also has one or more springs to urge the
teeth into engaging contact. The preferred device also
; nr~ Pc a latch to hold the swing lock segment in a
r5; CC~ AlJ~I position until the piston is activated to
engage the swing lock. With this design, a sudden
interruption of ~~ esse~ air or hydraulic fluid to
the piston does not result in automatic ~nga~ ~ of
the swing lock. Also, the crane can be shut down with
the swing lock left ~l; c~-n~a~ed so that the crane can
"weather vane" to present the least wind resistance.
These and other advantages of the invention,
as well as the invention itself and advantages of the
quick ~1; cf-nnn~rt system, will best be understood by
ref erence to the attached drawings, a brief description
of which follows.
~3RIEF DE~-acls-~llON OF THE DRAWINGS
Fig. 1 is a perspective view of a crane
in~_u.~,L~ting a quick r5; CC~nn~l-t system and a swing
lock - Ani~m of the present invention.
Fig. 2 is a sectional view taken along
line 2-2 of Fig. 1.
Fig. 3 is a sectional/plan view taken along
line 3-3 of Fig. 2.
Fig. 3a is an enlarged plan view taken along
line 3a-3a of Fig. 3.
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Fig. 3b is an enlarged plan view taken along
line 3b-3b in Fig. 3.
Fig. 4 i5 an enlarged sectional view taken
along line 4-4 of Fig. 3.
Fig. 5 i5 a sectional view taken along
line 5-5 of Fig. 4.
Fig. 6 is an enlarged, partial sectional view
taken along line 6-6 of Fig. 3, showing the swing lock
c~h;~n;~ of the present invention.
Fig. 7 is a partial sectional view taken
along line 7-7 of Fig. 6.
rATT~n l~h~ ~LlON OF T~E DRAWINGS AND
KK~:IJ F~MR-)DTM~NT OF TT~ INVFNTION
While the present invention will find
application in all types of c~ aLLu~ion equipment, the
preferred ~mhodi- t of the invention is described in
conjunction with the crane 10 of Fig. 1. The crane lo
includes an upper works 12 rotatably supported on a
mobile lower works 14. The upper works 12 and lower
works 14 are conventional. The upper works 12 includes
a boom 15 and rigging 16, backhitch 17, a gantry 18,
counterweight l9 and power equipment (not shown)
enclosed by a housing 20. The lower works 14 includes
a body 22 and two i n~er~n~ntly powered crawler treads
24 .
As best seen in Fig. 2, in the crane 10 the
upper works 12 is, nnnect ,rl to the lower works 14 by a
quick separation and assembly apparatus. The upper
works 12 rests on an adapter plate 30, which in turil
rests on a swing bearing 40. The bearing 40 in turn
rests on the body 22 of the lower works 14. As
described more fully hereafter, the adapter plate 30 is
secured to the upper works 12 by means f or releasably
connecting the adapter plate 3 0 to the upper works 12 .
In the c-mho~;r ~ shown, the releasably connecting
means comprises links 60, shown in Fig. 2, pinned to
the upper works 12. With the shape of the housing 20
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shown in Fig. 1, the links 60 attach to the body of
upper works 12 inside of the housing 20. Of course,
where other housing shapes are used, the adaptor plate
30 may extend further than the housing 20, and the
links 60 will then be visible outside of the housing
20 .
The bearing 40, as best seen in Fig. 4, is of
conventional design, with a one-piec~ inner race 42
having drive teeth 44 integrally ~ormed thereon. The
inner race 42 is bolted to the body 22 o~ the lower
works 14 by torqued bolts 46. A f;ni-:hin~ pad 48,
h i n-~9 to provide good vertical load transf er, sits
between the body 2 2 and the inner race 4 2 .
The outer race 50 is made of two pieces,
upper member 52 and lower member 53. Torqued bolts 54
hold the two members 52 and 53 together and hold the
outer race 50 to the adapter plate 3C. Rollers 55, 56
and 57 ride between the inner race and the outer race.
A fini~:hin~ pad 58 rests between the outer race 50 and
the adapter plate 30.
The adapter plate 30, as best seen in Figs.
3, 3a, 3b and 4, comprises a generally rectangular
plate member 32 with front tangs 34 and rear tangs 39
extending at its four corners. The adapter plate 30
has circular ~peLl_uLe, 86 through plate 32 through
which drive gears ~it to engage the drive teeth 44.
Those gears (not shown) are journaled in brackets
mounted on the upper works 12. The power generating
equipment of the crane 10 is used in a conventional
manner to effectuate rotation of the upper works 12
relative to the lower works 14 via power transmitted
through aperture~ 86. A larger aperture 8~ in the
adapter plate provides access for other power and
control connections between the upper works 12 and the
lower works 14.
A smaller circular aperture 83 is used to
align the adapter plate 30 with the upper works 12. A
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pin 70 (Fig. 4) fits through a bushing 72 affixed to
the floor 21 of the upper works 12, and through
~pt:LLUL~ 83. An annular shaped f;n;~hin~ pad 77 rests
between the adapter plate 30 and the floor 21 of the
upper works 12 surrounding aperture 83. Pin 70 has a
head 71 that provides a cholllflpr to rest on bushing 72.
Shear blocks 73 (Fig. 3, 3a and 3b) are welded onto the
top of adapter plate 30 near rear tangs 39 on a part of
the adaptor plate 3 0 so that the rear of the upper
works 12 will fit between them. The pin 70 and 5hear
blocks 73 transmit horizontal and torque loads between
the upper works 12 and the adapter plate 30.
The adapter plate 30 also includes finichin~
pads 78 at each corner covering the tangs 34 and 39,
and a finishing pad 79 covering about five-twelfths of
the area over the outer race 50. Pad 79 is centered in
the front portion of the adapter plate 30. Threaded
holes 35 through the adapter plate 30, and through
f i n i ch i n~ pad 79, ac '~te bolts 54 .
The adapter plate 3 0 includes a circular
reinforcing rib 31 Cv~ lLLiC with and spaced outside
of the outer race 50. The adapter plate 30 also
includes a number of additional reinforcing ribs,
including flat reinforcing ribs 33 extending from the
circular reinforcing rib 31 to each of front tangs 34,
flat reinforcing ribs 36 extending from the reinforcing
rib 31 to the rear tangs 39, and an arcuate reinforcing
rib 37 extending between rear tangs 39. Reinforcing
ribs 31, 33, 36 and 37 are welded to the bottom of the
adapter plate 30 to provide additional rigidity to the
adapter plate 3 0 . In the ~hofl i r ~ L shown, additional
plate material 38 is welded to the bottoms of the
reinforcing ribs 31, 36 and 37 to form a box-like
structure and add additional rigidity to the adapter
plate 30. As best seen in Figs. 3a and 3b, the bottom
side of both of the rear tangs 39 is covered by a
doubler plate 74 of high yield steel. A counter
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bore 75 is made in the doubler plate 74 for attachment
of the links 60, as explaLned below. (For clarity,
links 60 are not shown in Figs. 3a and 3b. )
~ he links 60, in conjunction with the pin 70
and shear blocks 73, releasably connect the adapter
plate 30 to the upper works 12. Four links 60 are
uGed, one at each corner of the adapter plate 30. As
best 6een in Figs. 4 and 5, the links 60 ~aach comprise
two spaced apart pieces of steel strap 62, &~i~nnin~
between the point of the connection of the link 60 to
the upper works 12 and the base of the link 60. Each
strap 62 is wider at its ends than in its central
section. The top end 64, best seen in Fig. 2, includes
a hole for a pin 63 which is used to pin the straps 62
to the upper works 12. Cotter pins (not shown) hold
the pins 63 in the upper works. The bottom end 66 is
rectangular in shape. As shown in Fig. 5, a base block
68 is welded between the rectangular ends of the straps
62. The straps 62 are spaced by the base block 68 so
that the tangs 34 and 39 of adapter plate 30 fit
between each set of straps 62. A jacking bolt 65
extends through the base block 68 and into the counter
bore 75 of the doubler plate 74 on rear tangs 39.
Similar counter bores 75 (Fig. 5) are formed in the
underside of front tangs 34 for receiving jacking
bolts 65 for the links 60 at the front of the adaptor
plate. A jam nut 67 is used to prevent the bolt 65
from getting loose during crane operation. The weight
of the upper works 12 and the tension in the links 60,
transferred through the pins 63 and jacking bolts 65,
holds the upper works 12 f irmly onto the adapter plate
30.
A swing lock ~- ~ni ~n is used to prevent
rotation of upper works 12 about the lower works 14
when the crane 10 is used in a mode where rotation is
to be avoided, or when not in operation and it is not
desired to let the crane "weather vane. " A preferred
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g
swing lock ~hAni.~m for use in conjunction with the
adapter plate 30 is shown in Figs. 6 and 7. The
r-^hAni cm is held to the underside of adapter plate 30
by welded plates 88 and 89.
The swing lock o --hAni pm comprises a swing
lock segment 90, a connector link 91, a latch 92, a rod
end 93, an air cylinder 94 with a piston rod 95 to
which the rod end 93 is attached by a bolt 96, side
plates 98, a bottom plate 99 and end plate 100. Two
return springs 97 are positioned between end plate 100
and swing lock segment 90. The ends of springs 97 are
held in bores 108 in the end of swing lock segment 90
and cup members 109 fixed to end plate 100.
A pin 110 pivotly holds the connector link 91
to the swing lock segment 90. Swing lock segment 9o
has three teeth which intermesh with drive teeth 44 on
the inner race 40 when the piston 95 is extended to
engage the swing lock ~ hAniPm. The rod end 93 is a
clevis-shaped member which goes along both sides of the
back of connector link 91. A downward pointing
triangular slot 101 is formed horizontally in rod end
93. The slot 101 accepts a pin 111 fixed in the end of
connector link 91 opposite pin 110.
The faces of rod end 93 oriented towards the
drive teeth 44 are sloped forward at an approximate 600
angle. The top surface of connector link 91 includes a
notch 102. The bottom surface of connector link 91
in~ c a leg 103 for sliding along the bottom plate
99, and terminates in a foot 104 which fits into a hole
105 formed in bottom plate 99, directly below the pin
111 .
When the swing lock r ~-hAn i cm is to be
disengaged, air cylinder 94 is activated to retract
piston rod 95. This forces the rod end 93 to start
moving toward end plate 100. As it does so, the pin
111 starts to ride up in slot 101, lifting foot 104 out
of hole 105. Once pin 111 reaches the upper corner of
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slot 101, further retraction of piston rod 95 draws
connector link 91, pin 110 and swing lock segment 9Q
away from drive teeth 44, es~ing springs 97. When
the swing lock ~ ni~- is in its fully retracted
position, latch 92, which is also clevis-shaped with
its open end opposite the open section of rod end 93,
falls over notch 102 of connector link 91 and rests
against the sloped face of rod end 93. The latch 92
holds the swing lock segment 90 from engaging drive
teeth 44 in case of failure of the pneumatic system or
when weather vaning is desired.
When the swing lock ~ ' Ini P:m is to be re-
engaged, air cylinder 94 Ls activated so as to force
piston rod 95 outward. As piston rod 95 moves rod end
93 forward, latch 92 slides up the sloped face of rod
end 93, disengaging notch 102 on connector link 91.
Return springs 97 are then free to push swing lock
segment 90 back into an engaged position as shown in
Figs. 6 and 7. As connector link 91 moves toward teeth
44, foot 104 is again free to drop into hole 105, which
provides a rigid contact to keep the swing lock segment
90 engaged with drive teeth 44. Should drive teeth 44
not be lined up with the teeth on swing lock segment
90, the piston rod 95 is rree to move to its fully
extended position because the pin 111 can move to the
back side of triangular slot 101. Once the teeth are
aligned, springs 97 will force the swing lock segment
90 forward and rod end 93 will move to the position
shown in Fig. 6.
The latch 92 of the swing lock -- -n;Fm
provides a means to prevent the swing lock segment 9 o
from engaging the drive teeth in the event of a power
failure such as a break in the air line to cylinder 94.
Also, the latch 92 can be left engaged while the crane
is shut down so that the swing lock r- ' -ni ~m does not
prevent the crane from rotating in response to changes
in wind direction. On the other hand, connector
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link 91 with foot 104 mated with hole 105 provides a
means for rigidly holding the swing lock segment 90 in
its engaged position to prevent the swing lock segment
90 from ~liq~n~ing when resisting a swing torque,
rather than relying only on the force of springs 97 or
the cylinder 94 to prevent the swing lock segment 90
from tl; q~n~a~ing. The springs 97 allow for quick
engagement of the swing lock segment 90 without
requiring further movement of the piston, avoiding
dragging the piston out of the cylinder and working
against the attendant friction and other forces
present .
The described ~m-~nrl i ~ ~ of the quick
~9 i qcnnn~ct system provides numerous advantages . The
crane lO can be quickly t9;~;~q5Pmhled by loosc~nin~
jacking bolts 65, swinging links 60 free of the adaptor
plate 30 and lifting upper works 12 off of the adapter
plate 30. RP~q~ ' ly is also rather simple, only
requiring ~ L of bushing 72 with aperture 83,
drive gears with ape~Lu~es 86 and the outside of upper
works 12 between shear blocks 73. As shown in Fig. 4
and 3a, the lower end of pin 70 dnd thè upper parts of
shear blocks 73 are rounded to facilitate ~l i,; -nt.
Because of the rigidity of the adapter plate
30, it may be possible to reduce the thickness of the
floor 21 and other members o~ the upper works 12, thus
making the upper works 12 lighter. Most importantly,
the quick ~ i qconn~rt system is relatively i n~yr~nsive
because it uses conventional swing bearings, and may
also therefore be interchangeable with other bearings
on other crane parts . The adaptor plate 3 0 is
particularly useful with swing bearings using rollers
as shown, as well as ball-type swing bearings.
In the preferred embodiment of the crane 10,
the various elements are made of steel, sized in
accordance with good engineering design practice f or
the crane with which the adapter plate will be used. A
WO 93/20005 2 1 ~ 9 g 3 ~ i 12 - PCI`/US92/026~
preferred steel for the doubler plates 74 has a 100,000
psi yield.
Of course, a number of modifications may be
made to the pref erred Pn~hofl; - ^nt disclosed above . For
example, ~PrPnflin~ on the size of the crane, an
additional pin such as pin 70, rather than shear blocks
73, may be required on the back of the adapter plate 30
to prevent twisting between the upper works 12 and the
adapter plate 30. A hydraulic cylinder could be used
in place of the air cylinder 94. Freely floating rods
could be placed inside of return springs 97 to act as
anti-o~ckl; nq elements where the spring material is not
heavy enough on its own to prevent b~ ; ng, In a less
preferred Pmhofl;--rL~ the adapter plate 30 could be
releasably r~nnPrtPfl to the lower works, with the
bearing and adapter plate 30 staying fixed to the upper
works when the equipment is fl; ~ Pmhl ed f or transport .
It should be appreciated that the apparatus
and methods of the present invention are capable of
being inC~L~uL~ted in the form of a variety of
Ls, only a few of which have been illustrated
and described above. The invention may be embodied in
other forms without departing from its spirit or
essential characteristics . The described P-nho~; r - Ls
are to be considered in all respects only as
illustrative and not restrictive and the scope of the
invention is, therefore, indicated by the appended
claims rather than by the foregoing description. All
changes which come within the meaning and range of
equivalency of the claims are to be embraced within
their scope.
