Classifications

• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11C—STATIC STORES
  • G11C27/00—Electric analogue stores, e.g. for storing instantaneous values
  • G11C27/02—Sample-and-hold arrangements
  • G11C27/024—Sample-and-hold arrangements using a capacitive memory element
  • G11C27/026—Sample-and-hold arrangements using a capacitive memory element associated with an amplifier
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F3/00—Dredgers; Soil-shifting machines
  • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
  • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
  • E02F3/36—Component parts
  • E02F3/42—Drives for dippers, buckets, dipper-arms or bucket-arms
  • E02F3/43—Control of dipper or bucket position; Control of sequence of drive operations
  • E02F3/431—Control of dipper or bucket position; Control of sequence of drive operations for bucket-arms, front-end loaders, dumpers or the like
  • E02F3/434—Control of dipper or bucket position; Control of sequence of drive operations for bucket-arms, front-end loaders, dumpers or the like providing automatic sequences of movements, e.g. automatic dumping or loading, automatic return-to-dig
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/20—Drives; Control devices
  • E02F9/2004—Control mechanisms, e.g. control levers
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11C—STATIC STORES
  • G11C27/00—Electric analogue stores, e.g. for storing instantaneous values
  • G11C27/04—Shift registers

Definitions

• This invention relates generally to a linkage means for transferring a mechanical signal across a pivot axis connecting a first member to a second member and more particularly to a linkage means for a bucket positioner system for a loader vehicle.
• Conventional loader vehicles are adapted to perform various digging, loading and carrying operations during a cycle of loader operation.
• phases of the loading operation such as rack-back of thebucket after it has been loaded, it is desirable to provide means to continue the rack-back action, once such action is initiated by the operator, and to stop such action automatically when the bucket arrives at a predetermined position.
• Such automatic operations are generated typically by devices called, respectively, detent means and detent release means. They allow an operator to be free td direct his attention elsewhere, as needed.
• Release means have included various cable coupling schemes for transferring a detected degree of extension of a tilt cylinder rod to a detent release control means.
• Such coupling structures generally include flexible control cables that couple, either hydraulically or mechanically, control signals to the detent release control means. Flexibility is required because the tilt cylinder pivots with respect to the loader vehicle operator controls.
• the sliding contact between the bolt and the lever can cause the linkage to bind. Also, since the kickout occurs at the maximum movement of the roller, sufficient force is not always provided to overcome such binding and to transmit movement to the second lever. Further, the location of the bolt is such that adjustment is not easily made.
• the present invention is directed to overcoming one or more of the problems as set forth above.
• an improvement is provided in an apparatus having first and second members which are pivotally mounted relative to one another about a pivot axis, the first member having first and second operating conditions.
• the apparatus has linkage means for transmitting a mechanical signal across the pivot axis, which linkage means has a first link structure pivotally mounted relative to the first member and defining a generally circular cam surface, the first link structure being pivotable to first and second positions relative to the first member.
• the apparatus also has a second link structure having first and second positions and being pivotally mounted relative to the second member, the second link structure defining a ⁇ oacting surface which the cam surface contacts with the first link structure in its first position to define the first position of the second link structure.
• Means are provided for moving the second link structure to its second position in response to movement of the first link structure to its second position.
• Mechanical signal originating means serves for moving the first link structure to its first and second positions in response to the first member being respectively in its ' first and second operating conditions.
• the improvement of the present invention comprises a roller having a center and being mounted at its center to the first link structure, the roller defining the circular cam surface; a generally U-shaped member having a pair of legs having outfacing sides is mounted to the second link structure, one of the outfacing sides defining the coacting surface; and means for adjusting the generally U-shaped member tangentially and radially relative to the roller. Utilizing an improvement as set out above, adjustment of the linkage is provided via adjustment of the U-shaped member.
• the adjusting means can be, for example, a bolt which passes through the U-shaped member and provides both the tangential and radial adjustmen of the U-shaped member relative to the roller.
• the roller can also be positioned slightly overcenter whereby as play develops in the linkage with wear, kickout of the bucket will still occur in the required manner. Still further, adjustment of the linkage is relatively easy since it only requires adjustment of the adjusting means, for example, a bolt which passes through one leg of the U-shaped member and contacts the other leg thereof to provide a controllable contract force between.the 'roller and the U-shaped member. The same bolt can serve for adjusting the U-shaped member 'axially relative to the second link structure. Thus, simple straightforward adjustment is possible via adjustment of an easily accessible single bolt. Further, the adjustability of the roller overcenter provides additional force for kickout after the desired kickout position is reached.
• Figure 1 illustrates, in a side elevational view, a loader vehicle employing apparatus in accordance with an embodiment of the invention
• Figure 2 illustrates, in enlarged side view, a tilt cylinder with linkage means installed thereon in accordance with an embodiment of the present invention
• Figure 3 illustrates, in further enlarged view, the improved linkage in accordance with an embodiment of the present invention
• Figure 4 illustrates, in still further enlarged view, improved apparatus' in accordance with an embodiment of the invention
• Figure 5 illustrates, in partial view, a view taken along line V-V of Figure 4, with all portions other than the generally U-shaped member and the lever to which it is mounted excluded.
• FIG. 1 illustrates a loader vehicle 10 having a frame 11 having a pair of pivot arms 12
• the lift arms 12 have a bucket 14 pivotally mounted on the forward ends thereof by
• Each lift arm 12 is adapted to be selectively raised or lowered by a pair of double- acting hydraulic cylinders 16 (one shown) pivotally mounted on frame 11 and the lift arms 12 by pivot pins 17 and 18, respectively.
• a standard tilt or bucket positioner means 19 is pivotally interconnected between the lift arms 12 and the bucket 14 to move the bucket 14 to a desired position.
• the tilt linkage 19 includes a hyd aulically actuated double acting cylinder 20 pivotally mounted to the frame 11 by a pivot pin defining a pivot axis 21.
• Cylinder 20 has a rod 22 reciprocally mounted therein to be selectively extended or retracted thereby.
• the extension of the rod 22 from the tilt cylinder 20 ' causes the bucket 14 to tilt forward into a "dump" attitude.
• Retraction of the rod 22 into the cylinder 20 causes the bucket 14 to tilt back in a rearward direction toward th vehicle 10. This attitude of the bucket 14 is termed "rack-back".
• a typical operator control for actuating the cylinder 20 and thus controlling the position of the bucket 14 is a hand lever 6 * connected to a hydraulic control valve 8 mounted on the frame 11.
• the valve 8 is typically of a spool type, spring centered to a neutral position (N) between the dump (D) and rack-back (R) command positions, with a detent and detent release mechanism at the Rposition.
• the rearward rotation of the bucket 14 will stop when the operator releases the lever 6 and allows the valve 8 to return to its N position. If the lever 6 is moved back fully to the R command position, the detent engages to hold the valve 8 at that position to thereby enable the bucket 14 to automatically continue to rotate in a rearward direction, or roll-back, without need for the :> operator to continue holding lever 6 in the R position. The bucket 14 will continue to rotate back until a detent release signal is detected by the valve 8, at which time the rack-back is automatically stopped.
• the detent release signal is usually produced by the automatic detection of a given retraction (or extension, if desired) of rod 22 in
• rod 22 need not be fully retracted before the detent release signal is generated. Retraction of the bucket 14, beyond the point when a detent release signal- is generated, is useful under the manual control of lever 6 only, since the bucket 14 in such a mode could be used to pry loose materials being excavated, for example, without the actuation of the detent means. This is because such excavation requires successive roll-back commands. It would be inefficient to constantly require the operator to release the detent means when the detent means can be kept off by the detent release signal.
• the cylinder 20 can more generally be thought of as a first member and the frame 11 as a second member, which members are pivotally mounted relative to one another about the pivot axis 21.
• the cylinder 20 has both a first operating condition 32 (corresponding to lever 6 being moved toward the D position) and a second operating condition 34 (corresponding to lever 6 being moved toward the R position) .
• the first operating condition 32 is the dump position shown in Figure 1 and the second operating condition 34 is the rack-back condition shown in Figure 2.
• linkage means 30 serves for transmitting a mechanical signal across the pivot axis 21 (seen in Figure 1) .
• the linkage means 30 includes a first link structure 36 which is pivotally mounted relative to the first member 20. More particularly, the first link structure 36 is pivotally mounted to a support 38 which is itself
• the first link structure 36 defines a generally circular cam surface 42 as part of a roller 44 which is mounted to a first end portion 46 of the first link structure 36.
• the first link structure 36 is pivotable to first 48 and second 50 positions relative to the cylinder 20, as illustrated in Figure 3.
• a second link structure 52 has first 54 and second 56 positions, as is also illustrated in Figure 3.
• the second link structure 52 is pivotally mounted at 58 relative to the frame 11.
• the second link structure 52 defines a coacting surface 60 which the cam surface 42 contacts with the first link structure 36 in its first position 48. This serves to define the first position 54 of the second link structure 52.
• Means 62 which, in the embodiment illustrated is a spring 64, serves for moving the second link structure 52 to- its second position 56 in response to movement of the first link structure 36 to its second position 50.
• mechanical signal originating means 66 serve for moving the first link structure 36 to its first 48 and second 50 positions in response to the cylinder 20 being respectively in its first 32 and second 34 operating conditions.
• the mechanical signal originating means 66 illustrated includes a lever 68 centrally pivotally mounted at a pivot 70 relative to the cylinder 20.
• a first end 72 of the lever 68 has a roller 74 which is positioned to be contacted by a bar 76 which moves axially with the rod 22 of the cylinder 20.
• a second end 78 of the lever 68 is connected to a rod structure 80, which is also pivotally connected to a second end portion 82 of the
• the rod structure 80 ( Figure 3) includes means 86 for adjusting the first link structure 36 relative to the cylinder 20 for positioning a center 88 of the roller 44 a selected distance over the pivot axis 21.
• the means 86 comprises threads 90 on a first section 92 of the rod structure 80.
• the rod structure 80 can be shortened to force the first link structure 36 to be biased somewhat in a clock ⁇ wise direction whereby the roller 44 will be moved leftwardly and upwardly against the coacting surface 60.
• the center 88 of the roller 44 is aligned with the pivot axis 21.
• the center 88 of the roller 44 is positioned a slight selected distance overcenter, i.e., over-the pivot axis 21. This provides a built in allowance for wear of various components of the linkage. That is, readjustment is not necessary until the center 88 of the roller 44 has been moved backward passed the pivot axis 21 due to wear on the various components. Since the center 88 of the roller 44 is very near
• a generally U-shaped member 98 preferably constructed of a metallic flat plate spring material and seen best in Figures 4 and 5, has a pair of legs 100 and 102 having outfacing sides 104 and 106 respectively.
• the generally U-shaped member 98 is mounted to the second link structure 52, more particularly to a first end portion 108 of a first lever 110 which is a part of the second link structure 52, and is generally centrally pivotally mounted to the frame 11 at 58. More particularly, the generally U-shaped member 98 is mounted with one of its legs 102 in contact with the roller 44 and with the other of its legs 100 mounted to the first end 108 of the first lever 110.
• the other leg 100 of the generally U-shaped member 98 has a slot 112 therein extending lengthwise through which an adjusting bolt 114 fits.
• An appropriate flat washer 116 is interposed between a locking nut 118 and the other side.100 of the generally U-shaped member 98 (see Figure 4) .
• Member 98 is thus extensible and retractable with respect to lever 110.
• the adjusting bolt 114 which is threaded in the first end 108 of lever 110, can be advanced or retracted relative to the other leg 100 of the generally U-shaped member 98, thereby forcing an end 120 of the adjusting bolt 114 to bear against the one leg 102 of the generally U-shaped member 98 to force the side 106 of the generally U-shaped member 98 to closely conform with the shape of the roller 44.
• the locking nut 118 is then used to tightly secure member 98 and. bolt 114 in place.
• the adjusting screw 114 /along with the slot 112, the washer 116 and the nut 118 serve as means 122 for adjusting the generally U-shaped member 98 tangentially and radially relative to the roller 44.
• the previously discussed spring 64 which serves for biasing the second link structure 52 towards its second position 56, also serves as means for biasing the coacting surface 60, i.e., the side 102, of the generally U-shaped member 98, against the cam surface 42 defined by the roller 44.
• the first lever 110 has a second end portion 124 to which the spring 64 is attached.
• the second end portion 124 of the first lever 110 also defines a generally flat surface 126 facing generally in an opposite direction from the spring 64.
• a second lever 128 also forms a part of the second link structure 52.
• This second lever 128 is secured to a pivot shaft 130 of the control valve 8.for actuation of the cylinder 20.
• the second lever 128 has an end portion 132 having a generally flat surface 134 which contacts the generally flat surface 126 on the second end portion 124 of the first lever 110.
• the second lever 128 is likewise rotated.
• a signal is sent to the detent release control means of the valve 8.
• a structure which accomplishes this can be that shown in previously mentioned U.S. Patent 4,020,963, or can be any of a number of relatively simple structures which form no part of the present invention. It is noted that the internal spring loading of the valve 8 serves to bias the generally flat surface 134 of the second lever 128 against the generally flat surface 126 of the first lever 110. Thus, the surfaces 126 and 134 are kept in contact.
• the detent release control means in the conventional manner and as set out in the previously mentioned U.S. Patent 4,020,963, stops the automatic retraction of the rod 22 which, in the preferred embodiment, thereby stops the rack-back of the bucket 14 at the desired point.
• the apparatus 19 of the present invention is particularly useful with a conventional loader vehicle 10 of the nature illustrated in Figure 1.
• a linkage 30 which will sense a given length of a telescoping tilt cylinder 20 which, is also pivotally attached to the vehicle 10 at a pivot axis 21 and wherein the linkage 30 will transfer a mechanical signal across the pivot axis 21 of the tilt cylinder 20 to the frame 11 within the limits of the operative pivot angles of the tilt cylinder 20, regardless of the cylinder angular attitude.
• Very easy adjustability is provided.
• a roller 44 can be adjusted over the pivot axis 21 of the cylinder 20 to the frame 11, generally only a few millimeters, to provide insensitivity to a limited degree of wear of the components of the linkage 30.
• the prior art sliding contact between the adjusting bolt and a lever, which promotes binding of the linkages, is eliminated. Because of the capability of adjusting the roller 44 over the center of the pivot axis 21 of the cylinder 20 to the frame 11, additional force is provided for kickout after the desired kickout position is reached.

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• Engineering & Computer Science (AREA)
• Mining & Mineral Resources (AREA)
• Civil Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Mechanical Engineering (AREA)
• Operation Control Of Excavators (AREA)
• Shovels (AREA)
• Mechanical Control Devices (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

Family

ID=22154441

Family Applications (1)

Country Status (6)

Families Citing this family (1)

Citations (2)

• 1980
  • 1980-07-10 JP JP81501290A patent/JPS57500988A/ja active Pending
  • 1980-07-10 WO PCT/US1980/000885 patent/WO1982000310A1/en active Application Filing
  • 1980-07-10 BR BR8009087A patent/BR8009087A/pt unknown
  • 1980-07-10 JP JP81501290A patent/JPS6321767B2/ja not_active Expired
  • 1980-07-10 DE DE19803050483 patent/DE3050483A1/de active Granted
• 1981
  • 1981-03-30 CA CA000374124A patent/CA1137928A/en not_active Expired
  • 1981-05-27 FR FR8110644A patent/FR2486612A1/fr active Granted

Patent Citations (2)

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