United States Patent [1 1 Dunbar [4 1 July 8,1975
[ HYDRAULIC LINE ASSEMBLY 221 Filed: Dec. 26, 1973 [21] Appl. No.: 427,986
[52] US. Cl 137/615; l37/355.l7 [51] Int. Cl Bh /36 [58] Field of Search..... 137/355.16, 355.17, 355.18, l37/355.19, 355.20, 355.22, 355.23, 355.24, l37/355.25, 355.26, 355.27, 355.28, 615, 344; 285/133, 134; 239/ Primary ExaminerCharles .1. Myhre Assistant Examiner-Ira S. Lazarus Attorney, Agent, or Firm--Richard D. Emch; Thomas M. Freiburger [57] ABSTRACT A hydraulic tube and hose assembly for use on a crane having a telescoping boom. The assembly includes a coaxial hydraulic conduit mounted for travel with the extending arm of the boom and slidably connected to the non-extending portion of the boom. The coaxial conduit is of a length greater than the throw of the telescoping boom, so that upon extension of the telescoping arm, the conduit travels along with an gener ally parallel to the arm. The forward end of the coaxial hydraulic conduit is connected to a hydraulically operated implement mounted on the end of the boom, while the rearward end of the conduit is connected to a pair of flexible hydraulic lines leading to a stationary portion of the crane and ultimately to a hydraulic fluid supply. The flexible hydraulic lines define a curve of which migrates during extension of the boom from a rearward position adjacent the end of the conduit to a forward position adjacent a line divider guide, thereby reducing the probability of injury to the hydraulic line and providing a determined course of travel for the hydraulic line during extension and retraction of the boom.
6 Claims, 9 Drawing Figures @AIEETFDJUL 8 ms SHEET 1 HYDRAULIC LINE ASSEMBLY BACKGROUND OF THE INVENTION The invention relates to construction or other equipment having an extendable outer arm and more particularly to cranes having telescoping booms to which are mounted hydraulically operated equipment.
Cranes with telescoping booms which carry hydraulically operated implements generally employ flexible fluid lines to connect the hydraulic implements with a stationary hydraulic supply, for example, a hydraulic fluid pump. The lines traversing the telescoping boom must be of sufficient length to accommodate the fully extended telescoping arm. When the arm is partially or fully retracted, however, excess line is accumulated. Because the line cannot be allowed to hang loosely below the boom and catch on objects when the crane is in use, excess line must be stored somewhere in or on the boom. Existing storage arrangements generally result in wear and ultimate breaks in the flexible lines. This is due in part to the fact that the lines must slide along the non-extending portion of the boom in order to feed the extending arm and in part to the inevitable doubling up and rubbing of the line in various places along the line storage area as the boom is retracted.
In addition, the flexible lines on the extended telescoping arm are subjected to damage by contact with, for example, boxes or other objects being transferred by the crane implement.
SUMMARY OF THE INVENTION The present invention provides a telescoping boom hydraulic line assembly which reduces problems of line wear and breakage inherent in many prior art line arrangements. The assembly includes a storage chamber defined along the non-extending portion of the telescoping boom. Rigid hydrualic lines from a hydraulic source extend the majority of the length of the chamber, terminating in fittings aimed rearwardly. Flexible lines lead from these fittings to a connection at the rearward end of a rigid coaxial hydraulic conduit pipe.
In the telescoping booms retracted position, the coaxial conduit pipe extends substantially through the length of the storage chamber, through a slide mounting at the forward end of the chamber, and to the end of the telescoping arm of the boom, where it is rigidly mounted. From here, flexible lines connect the conduit with the hydraulically operated implement at the end of the boom.
In the retracted position of the boom, a gradual 180 bend is formed in the flexible line adjacent its connection with the rigid coaxial conduit. As the arm is telescoped forward, this bend advances forward at half the rate of the arm, taking up line which has previously been lying at rest in the storage chamber. When the boom is fully extended, the position of the bend is approximately mid-way along the length of the storage chamber. To prevent rubbing together of portions of the flexible line as the conduit approaches its full forward position, a longitudinally extending guide shield mounted within the chamber prevents the upper portion of the folded flexible lines from contacting the lower portion. The hydraulic tube and line arrangement of the present invention thus minimizes contact between portions of the flexible line, minimizes sliding contact of the lines with the storage chamber, and provides a rigid, slidably mounted tubular conduit where the lines must extend forward to accommodate the movement of the telescoping arm of the boom. Minimum friction is generated during extension and retraction of the telescoping boom.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an elevational view of a truck mounted crane with a telescoping boom employing apparatus according to the present invention;
FIG. 2a is the right half of an enlarged, partially broken away view of the telescoping boom of FIG. I;
FIG. 2b is the left half of the same enlarged view;
FIG. 3 is a sectional view taken along the
line 33 of FIG. 2a;
FIG. 4 is a fragmentary plan view taken along the
line 44 of FIG. 20;
FIG. 5 is a sectional view taken along the line 5-5 of FIG. 2b;
FIG. 6 is a sectional view of a coaxial conduit taken along the line 66 of FIG. 2b;
FIG. 7 is a cut away view of the telescoping boom partially extended; and
FIG. 8 is a cut away view of the telescoping boom fully extended.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. I of the drawings, a truck 10 is indicated having a crane mechanism generally indicated by the reference number 11. The crane 11 includes a first
pivotal boom 12 to which is connected a
telescoping boom 13. The
telescoping boom 13 includes a base or non-extending
portion 14 and a telescoping arm I6. On the
arm 16 is an
end 17 to which is attached a hydraulically operated
implement 18.
Hydraulic controls 19 regulate the flow of hydraulic fluid from a hydraulic supply including well known pumps and reservoirs (not shown). The hydraulic fluid passes through hydraulic lines 2], 22, and 23 to the
implement 18.
Referring now to FIGS. 20 and 2b, the telescoping boom is shown in an enlarged, detailed view. A
boom housing 24 receives the
telescoping arm 16. Mounted to the side of the
boom housing 24 is an
outer housing 26 which defines a
storage chamber 27.
FIGS. 2a and 2b show the
telescoping boom 13 in its fully retracted position. In such position, a coaxial
hydraulic conduit 30 extends from the rearward end of the
chamber 27 through the length of the
chamber 27 and through a slide bearing 31 to a
fixed connection 32 on the telescoping arm I6. As the
telescoping arm 16 is extended, the
coaxial conduit 30 slides through the slide bearing 31, which preferably has a lubricated
bearing surface 33, best seen in FIG. 3. A pair of rigid
hydraulic lines 34 lead from external
hydraulic lines 21 through the greater part of the length of the
chamber 27, bend to a rearward direction, and terminate in
fittings 36. Connected to the
fittings 36 are flexible
hydraulic lines 37 and 38 which are preferably attached to one another. In the fully retracted position of the telescoping boom as indicated in FIGS. 2a and 2b, the
flexible lines 37 and 38 extend back substantially linearly, then through 180
curves 39 and 40 to
fittings 41 and 42 on the
coaxial conduit 30. A
guide shield 43 having an angled
rearward leg 44 provides boundaries of the area in which the
flexible lines 37 and 38 may rest.
FIG. 7 indicates the positions of the
conduit 30 and the
lines 37 and 38 as the
telescoping arm 16 of the
boom 13. is extended forward. The
bends 39 and 40 in the
flexible lines 37 and 38 advance forward in the
storage chamber 27 at one-half the rate of advancement of the
conduit pipe 30 and
telescoping arm 16. Sliding friction between the
lines 37 and 38 and the stationary portions of the
storage chamber 27 is minimized. A forward longitudinally-extending
line guide shield 45 provides a divider between the upper portions of the folded
flexible lines 37 and 38 and their lower portions. thus minimizing friction between portions of the lines themselves.
FIG. 8 shows the
conduit 30 and
flexible lines 37 and 38 in the fully extended position of the
telescoping arm 16. The
bends 39 and 40 in the
flexible lines 37 and 38 have advanced to a position adjacent the end of the
forward guide shield 45, and the major portions of the
lines 37 and 38 lie in substantially linear position above the
shield 45. Some friction is encountered as the
lines 37 and 38 are drawn over the
line guide 45, but this friction is minimal.
FIG. 4 shows a portion of the
telescoping boom 13 in plan view, indicating that hydraulic line assemblies according to the present invention may be mounted on both sides of the
telescoping boom 13, when additional hydraulic lines are needed to operate equipment mounted on the end of such a boom. On both sides of the
boom housing 24 would be an
outer housing 26, a coaxial
hydraulic conduit 30, a
connection 32 to the
telescoping arm 16 and a
slide bearing 31.
FIG. also indicates, in section, a
telescoping boom 13 having dual hydraulic line assemblies.
Outer housings 26,
coaxial conduits 30,
line storage chambers 27,
hydraulic lines 37 and 38, and line guide shields 43 and 45 are shown on both sides of the
boom housing 24.
FIGS. 3 and 6 show details of construction of the
slide bearing 31 and the coaxial
hydraulic conduit 30 which slides within the
bearing 31. The
bearing 31 is preferably welded to a form fitted
slot 46 in a length of
channel 47 and is mounted to the
boom housing 24 by means of
bolts 48.
Bolts 49 connect the
outer housing 26 to the opposite flange of the
channel 47. The hear
ing 31 comprises an
outer sleeve 51 and an
inner sleeve 52 defining the lubricated
inner bearing surface 33 which guides the
coaxial conduit 30. A
set screw 53 retains the
inner sleeve 52 within the
outer sleeve 51. As seen in FIGS. 3 and 6, the
coaxial conduit 30 comprises an
outer tube 56 and an
inner tube 54, which are sealed at points 55.
The above described preferred embodiment provides a hydraulic line assembly which minimizes wear on hydraulic lines leading to hydraulically operated implements at the end of a telescoping boom. The assembly is simple, economical to manufacture and virtually trouble free. Various other embodiments and alterdent fluid transfer conduits. said rigid conduit as- V sembly having its forward end attached adjacent the forward end of such movable arm and its rearward end slidably mounted on such base section,
a plurality of flexible conduits positioned adjacent such base section, said flexible conduits having forward ends attached to and in fluid communication with said independent fluid transfer conduits, their other ends being in communication with the fluid supply source, and
a housing positioned on the exterior of the nonextending base section, said housing defining a chamber for receiving said flexible conduits and stationary divider means mounted within said housing for maintaining separation between portions of said flexible conduits during extension and retraction of the movable arm.
2. A hydraulic line assembly according to claim 1 wherein said stationary divider means commprises a longitudinally extending shield having a first end connected to said non-extending base section and within said housing and a second end spaced from said first end whereby said shield separates folded portions of said flexible conduit within said housing.
3. The hydraulic assembly of
claim 2, including guide means for slidably retaining said rigid conduit assembly adjacent said base portion, said guide means comprising a bearing rigidly mounted to said non-extending base section, said bearing slidably receiving said rigid conduit assembly.
4. The hydraulic line assembly of
claim 2 wherein said rigid conduit, in a fully retracted position of the movable arm, extends approximately the length of the base portion.
5. Apparatus according to
claim 2 wherein said rigid conduit comprises concentric tubes.
6. The apparatus according to
claim 2 wherein said plurality of flexible conduits are bound together substantially throughout their length.