JPS61266739A - Back hoe with insert type dipper stick - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD This invention relates generally to excavators with telescoping dipsticks, and more particularly to backhoe loaders with bayonet telescoping dipstick booms.

TECHNICAL BACKGROUND Backhoe loaders are becoming increasingly popular for earth movement and the transportation of some materials because they are relatively lightweight and have good workability. Backhoe loaders have become increasingly popular since the use of telescoping drill sticks has expanded the reach of the boom and, therefore, increased digging depth.

However, in the case of a telescopic dip stick, the boom wears out quickly because it expands and contracts frequently.

Accelerated wear is due to sliding friction between the telescoping dip stick and the boom portion that supports it. Various measures have been taken in the past to alleviate this wear problem.

These attempts have traditionally focused on providing means to limit the contact area, such as rollers, pads or wear plates, between the boom section and the telescoping dipstick. The use of fixed sliding mechanisms, such as rollers and pads, will substantially increase boom weight to make these mechanisms satisfactory. Particularly in the case of lightweight backhoe loaders, an increase in boom weight will result in a decrease in boom lift for a given backhoe size.

On the other hand, the wear plate was experimentally tested for 30 hours of use of the backhoe.
It has been found that the wear plate needs to be replaced at a frequency of use of every 0 hours. In addition, because the support boom portion of the telescoping dip stick is made of a steel material that is substantially less hard than the wear plate, the wear plate may deteriorate the boom support portion, resulting in replacement of the support boom portion. It becomes necessary.

SUMMARY OF THE INVENTION The boom section of a backhoe in accordance with the present invention includes a swing tower, a primary boom section, and a dipper boom section. The dipper boom section includes an elongate housing pivotally connected to one end of the boom section. The top wall, the bottom wall, and the opposing side walls form a dipper boom housing. A plurality of hardened wear plates are fixedly mounted within the top and bottom walls of the dipper boom housing and approximately the entire length of the can wall.

The telescoping dipstick has a corresponding top wall and opposing side walls on the bottom wall, and a top wall of the telescoping dipstick that is slidably mounted within the dipper boom housing. A plurality of hardened wear plates are fixedly attached to substantially the entire length of the outer surfaces of the bottom wall and the opposing side walls. The wear plates on the top and bottom walls of the telescoping dipper stick and the dipper boom housing are in abutting relationship in the longitudinal direction, and the dipper stick is slidably mounted within the dipper boom. It will be done. A wear plate attached to the side wall of the telescoping dipper longitudinally abuts the side wall of the dipper boom housing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The vehicle-mounted backhoe 11 shown in FIG. 1 (the vehicle is shown in dotted lines) is supported by a bin (not shown) at a position 15 in the frame of a vehicle or tractor for pivoting movement about a vertical axis. It has a swing tower 13.

Backhoe boom 17 is rigidly supported on swing tower 13 in a conventional manner. Boom 17 has one end connected to tower 1.
3 has a partial boom portion 19 rigidly attached to it. The dipper boom section 21 is pivotally connected at one end thereof to the other end of the boom section in a conventional manner. The hydraulic cylinder 23 is partially attached to the boom section 19 at one end and attached to the dipper boom section 21 at the other end by a bottle joint so that the dipper boom section 21 can be selectively pivoted.

As shown in FIGS. 1, 2 and 3, dipper boom 21 consists of a housing formed by first and second elongate members 31, 33, each having an inverted cross-section. members 31 , 33 are generally vertically extending and facing each other and are held spaced apart by an elongated member 35 ;
The corresponding horizontal portions of parts 31.33 thus form a gap 37. For convenience of explanation, the vertical portions of members 31.33 will hereinafter be referred to as side walls 31.33, respectively;
．． The horizontal portions of 33 are collectively referred to as a top wall 39. Member 35
is hereinafter referred to as the bottom wall 35.

The dipper boom section housing 21 further has an end place 45 fixedly mounted in a conventional manner around the free end 47 of the housing 21. A partially spaced rear plate 49 is fixedly mounted on the top wall 39 at the other end of the housing 21 in the conventional manner. Housing 21
A plurality of tension reinforcing tracks 51 on both sides of the gap 37 at the top wall 39 of the
is fixedly installed.

The telescoping dipstick 53 is slidably attached within the Ujifugu 21 in a plug-in manner, as will be explained in detail later. The telescoping dip stick 53 has each of an elongated top wall 55 and a bottom wall 57, and opposing elongated side walls 59.
61 and a tubular housing. One end of a hydraulic cylinder 63 is pivotally mounted within the forward end of the dipper boom housing 21 between the side walls 31.33 in a conventional manner. The other end of the hydraulic cylinder 63 is attached between the dipstick side walls 59.61 with a pin joint.

The bucket 64 is pivotally attached to the free end of the telescoping dip stick 53. The pivot linkage 65 is also attached to the telescoping date pass stick 53 and the bucket 64 by means of a bin joint in a conventional manner.
A support plate 86 is fixedly attached to the top wall of the dipper boom housing 2, and the support plate 86 is attached between the top walls 39 of the dipper boom housing 2 [37
and extends through the hydraulic cylinder 67 in the usual manner.
One end is pivoted. The other end of the hydraulic cylinder 67 is
It is pivotally connected to a linkage 65 in a conventional manner to provide selective pivoting movement of the bucket.

The operation of the dipper boom section and telescoping dipper stick is substantially as described in U.S. Pat. No. 3,140,000.

To reduce wear and tear on the dipper boom portion, a plurality of extendable wear plates are fixedly attached to the interior of the dipper boom housing 21 and the exterior of the telescoping dipper stick 53. In a preferred embodiment, the wear plate is made of hardened steel having a hardness of 42 on the Rockwell scale C. A plurality of first elongated wear plates 70 are fixedly attached within the top wall 39 of the dipper boom on either side of the gap 370 by conventional methods such as welding. A plurality of second elongate wear plates 72 are fixedly mounted laterally spaced within the bottom wall 35 .

A plurality of third wear plates 78 are fixed and removably attached to the outer surface of the bottom wall 57 of the expandable dipstick 53 adjacent to each of the wear plates 72 in the same vertical direction using a conventional method. It will be done. A plurality of fourth wear plates 80 are fixedly attached to the outer surface of the top wall 55 of the telescoping dipstick 53 adjacent to and in the same vertical direction as each of the wear plates 70 in a conventional manner.

On the outside of each side wall 59, 61 of the telescoping dipstick, a plurality of fifth and sixth nozzles are provided at intervals in a conventional manner.
elongated wear plates 74, 76 are fixedly and removably mounted.

The telescopic dipper stick 53 is dipper boom part 2
1, and this sliding support takes place between wear plates 70 and 80 and between wear plates 72 and 78. Wear plates 74 , 76 are adjacent the inner surface of each side wall of dipper boom housing 21 . The main wear areas of the telescopic dipstick are the interface between the wear plates 72 and 7°8 and the interface between the wear plates 70 and 80.

Effects of the Invention The wear characteristics of the telescopic dip stick according to the present invention are as follows:
It has been found that the wear characteristics are improved by a factor of 5 to 10 over the conventional plug-in dipsticks that use wear plates. Further, since the wear plates 74, 76, 78, 80 are removably attached, the wear plates can be replaced. By replacing the wear plate, the play between the telescoping dipper stick 53 and the dipper boom housing 21 can be restored to within an acceptable range. The present invention can improve wear characteristics without particularly affecting the weight of the pool.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a backhoe according to the present invention, FIG. 2 is a side view of a backhoe dipper boom portion, and FIG. 3 is a sectional view of a backhoe dipper boom portion. 17...Backhoe 19...Primary boom part 2
1... Ditsupa boom part (housing) 23.63
．． 67... Drive means (hydraulic cylinder) 31.33
...Side wall (of dipper boom housing) 35...
Bottom wall (of Ditsupa boom housing) 39...Top wall (
(of the Ditsupa boom housing) 53...Ditspa stick 55...Top wall (of the Ditsupa stick) 57...Bottom wall (of the Ditsupa stick) 59.61...Side wall (Ditspa stick) Tupa stick) 64...bucket
70...First wear plate 72...Second wear plate 7
4...Fifth wear plate 76...Sixth wear plate 78
...Third wear plate 80...Fourth wear plate (5 outsiders)

Claims (1)

[Claims] (1) In a backhoe having a primary boom portion and a dipper boom portion pivotally connected to one end of the primary boom portion, the dipper boom portion has a housing formed by a long top wall, a bottom wall and an opposing side wall, and a dipper boom housing. a telescoping dipper stick having a top wall, a bottom wall, and an opposing side wall corresponding to each wall, the retractable dipper stick being slidably mounted in the housing in a bayonet manner, and pivotally attached to one end of the retractable dipper stick; and means for selectively driving the dipper boom portion, the telescoping dipper stick, and the bucket; a plurality of first elongated wear plates fixedly mounted longitudinally and within the bottom wall of the housing;
A plurality of third wear plates are removably fixedly attached to the bottom wall of the telescoping dipper stick in the longitudinal direction so as to abut each of the second wear plates; a plurality of fourth wear plates abutting and fixedly attached longitudinally to the top wall of the telescoping dipper stick and longitudinally removable from the side wall of the telescoping dipper stick adjacent to one side wall of the housing; a plurality of fifth wear plates removably and fixedly mounted longitudinally to the side wall of the telescoping dipper stick adjacent the other side wall of the housing; An improved backhoe comprising: a wear plate;