Vibratory compactor

Abstract

A frame comprising a pair of inverted U-shaped side plate members interconnected by a pair of tubular cross members extending between opposed arm portions of the side plate members is attached to a boom. Four corner placed elastomeric shear springs are interconnected between such arm portions and upstanding corner members of a compaction plate. A hydraulic motor vibratory unit is mounted on the compaction plate within the tunnel region of the frame. A connector block is secured to the frame. Hydraulic fluid delivery and return lines are connected to the connector block. Half loops of flexible conduit, connected at their ends to the connector block and the hydraulic motor, serve to deliver hydraulic fluid from the connector block to the hydraulic motor and from the hydraulic motor back to the connector block. The lower ends of the arm portions of the frame side members extend downwardly below the springs to serve as stops, for limiting the amount of travel of the frame relative to the compaction plate.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to vibratory compactors, and in particular to an improved frame construction and an hydraulic fluid conduit arrangement for a boom mounted vibratory compactor.

2. Description of the Prior Art

Known boom mounted hydraulic motor driven vibratory compactors are disclosed by U.S. Pat. No. 3,427,939, granted Feb. 18, 1969 to Joseph A. Braff and Richard L. Fox; by U.S. Pat. No. 3,561,336, granted Feb. 9, 1971 to Bernard A. Century, and by U.S. Pat. No. 3,603,224, granted Sept. 7, 1971 to Seymour Dresher.

U.S. Pat. No. 2,224,506, granted Dec. 10, 1940 to Robert W. Baily and U.S. Pat. No. 3,450,012, granted June 17, 1969 to Bernhard Beierlein and Ulrich Beierlein disclosed compactors of a different type comprising a rotary eccentric weight mounted on the central portioin of a compactor plate and a drive motor which is mounted onto the eccentric weight housing in coaxial arrangement with the eccentric weight.

U.S. Pat. No. 3,732,022, granted May 8, 1973 to John H. Danuser discloses a compactor which includes a set of shear block type springs interconnected between a frame and compaction plate portions thereof.

SUMMARY OF THE INVENTION

The vibratory compactor of this invention is characterized by a unique frame construction which gives the compactor a low profile and permits location of a set of four elastomeric shear block springs at the four corners of the compactor in a manner resulting in a downward load being applied to all four corners of the compaction plate. The lower ends of arm portions of the frame side members are spaced inwardly of the shear block springs and are adapted to serve as limit of travel stops. Such location and arrangement of these stops minimizes the length of the moment arm between the shear block springs and the location of contact of the compaction plate with the ground, so that shear block springs are not over stressed by moments imposed on such springs. The stops also limit the amount of horizontal displacement of the compaction plate relative to the frame when the two are relatively together.

The vibratory unit is mounted on the compaction plate within the tunnel region of the frame and can be disassembled without first disconnecting the frame from the compaction plate.

Another very important feature of the invention is the manner in which the hydraulic supply and return conduits are arranged. A connector block is affixed to the frame closely adjacent the pivotal axis of the frame. It includes a delivery passageway having a generally horizontally directed inlet and an upwardly directed outlet, and a return passageway having a generally downwardly directed inlet and horizontally directed outlet. Hydraulic fluid supply and return lines are respectively connected to the inlet of the delivery passageway and the outlet of the return passageway. Lengths of flexible conduit are interconnected between the outlet of the delivery passageway and the inlet of the hydraulic motor, and between the outlet of the hydraulic motor and the inlet of the return passageway. Such lengths of flexible conduit extend upwardly from the connector block, then curve through a half loop, and then extend downwardly to the locations of connection with the hydraulic motor. Owing to this arrangement, during use of the vibratory compactor, when the frame is continuously moving relative to the compaction plate, there is essentially no movement of the supply and return conduits which connect to the connector block, only minimal flexure of the two lengths of flexible conduit in their extent between the connector block and the hydraulic motor, and no rubbing or chafing of any of the conduits.

These and other advantages will be apparent from the description of the preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an isometric view taken from above and looking towards one side and the outboard end of a vibratory compactor exemplifying the present invention, with the end of a boom to which such compactor is attached appearing in phantom;

FIG. 2 is another isometric view taken from the same aspect as FIG. 1, but of the frame assembly alone;

FIG. 3 is an exploded isometric view of the vibratory compactor of FIG. 1;

FIG. 4 is a side elevational view of such vibratory compactor, including solid and broken line showings of two extreme positions of hydraulic fluid delivery and return conduits which are interconnected between a connector block on the frame and a hydraulic motor on the compaction plate;

FIG. 5 is an end elevation view of the vibratory compactor, with the vibratory unit omitted, showing the shear block springs in an unloaded condition;

FIG. 6 is a view like FIG. 5, but showing the shear block springs evenly loaded to the limit; and

FIG. 7 is a view like FIGS. 5 and 6, but showing the shear block springs loaded in an uneven manner.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring first to FIG. 1, the vibratory compactor 10 comprises a frame 12 which is connected to a compaction plate 14 by four corner located elastomeric shear block springs 16. The frame 12 carries a first pivot pin 18 which is used for pivotally attaching the compactor to the end of a boom 20. It also carries a second pivot pin 22 which is used for connecting the compactor to a pair of control struts 24, in the usual manner.

According to the invention, the mounting frame 12 comprises a pair of substantially identical, inverted U-shaped side plate members 26, 28 (FIG. 2) and a pair of tubular cross members 30, 32 which are interconnected between opposed arm portions 34, 36, 38, 40 of the frame side members 26, 28. The tubular cross members are rigidly connected at their ends to the arm portions 34, 36, 38, 40 of the side plate members 26, 28 preferably by welding. The tubular cross members are large enough in diameter to substantially stiffen said arm portions, so that they will remain substantially planar during use of the compactor. This arrangement makes it possible to use relatively thin plate material for the side plate members 26, 28.

As best shown by FIGS. 2 and 3, opposed openings 42 are formed in the bight portions of the side plate members 26, 28 for receiving the pivot pins 18, 22. Reinforcement collars 44 may be welded to the members 26, 28 to provide reinforcement in the regions of the openings 42. Retainer collars 46 may be used at the ends of the pivot pins 18, 22, for holding them in place. Bolts 48 which extend through openings provided through the end portions of the pivot pins 18, 22 and also through the collars 46 may be used for securing the collars 46 to the pins 18, 22 with nuts 50 being used for holding the bolts 48 in place.

Referring now specifically to FIG. 3, the compaction plate 14 is connected to a frame 52 which includes four upstanding corner located connector plates 54, 56, 58, 60. In an installation wherein the side plates 26, 28, stiffened at the end of arms 34, 36, 38, 40 by tubes 30, 32, are 1/2 inch thick the plates 54, 56, 58, 60 may be about 11/4 inches thick. The elastomeric shear blocks 16 are at their ends bonded to a pair of mounting plates 62, 64. The plates 62 are secured to the corner plates 54, 56, 58, 60, such as by a set of four corner located nut and bolt assemblies 68. The plates 64 are secured to the stiffened arm portions 34, 36, 38, 40 of the frame 12, also by means of nut and bolt assemblies or the like.

The vibratory unit is attached directly to the compaction plate 14. It is located centrally of the plate 14 within the "tunnel" region of the frame 12. Owing to this mounting arrangement and location of the vibratory unit, such vibratory unit can be dismantled for servicing, etc., without it being necessary to disconnect the frame 12 from the compaction plate 14. Sufficient room exists for bringing the components of the vibratory unit endwise outwardly from the "tunnel" region 66.

As best shown by FIG. 3, the vibratory unit comprises a housing 69 having a curved top portion 70 and a pair of side members 72, 74. A rotating eccentric weight 76 is received within the housing 69. Bearing assemblies 78, 80 securable to the side walls 72, 74, mount the eccentric weight 76 for rotation. Coaxial end shaft portions 82, 84 of the weight 76 are received in the bearing assemblies 78, 80. A hydraulic motor 86 is secured to one end wall (e.g. end wall 72). It includes an output shaft (not shown) which is directly coupled to, and is in coaxial alignment with, the weight shaft 82. Such arrangement of the drive motor 86 to the eccentric weight 76 and the housing 69 is essentially like the arrangement that is shown in the aforementioned U.S. Pat. Nos. 2,224,506, 3,450,012 and 3,561,336.

According to the invention, a connector block 90 is affixed to the frame side wall 26, generally above the drive motor 86, and adjacent the pivotal axis of pivot pin 18. By way of typical and therefore non-limitive example, connector block 90 may include two right angle passageways therethrough, one for the fluid being delivered to the motor 86 and the other for the fluid being removed from the motor 86. Delivery and return lines 92, 94 are secured to the side located ends such passageways. A first length 96 of flexible conduit is interconnected between the upwardly directed inlet for the return passageway in connector block 90 and the outlet 102 of motor 86. As best shown by FIGS. 1 and 4, this arrangement results in the respective ends of the conduits 96, 100 being fixed to the frame 12 and the motor 86. Also by way of typical and therefore non-limitive examples conduits 96, 100 may extend first upwardly from connector block 90 and then curve generally through about 180.degree. and then extend downly to their points of connection to the inlet 98 and outlet 102 of motor 86. As shown by FIG. 4, during vibration movement of the compaction plate 14 relative to the frame 12, the conduits 96, 100 merely flex a slight amount between their fixed ends, resulting in very little fatigue and no abrasion. The supply and return hoses 92, 94 are easily coupled to and decoupled from the connector block 90. They undergo essentially no wear producing movement during use of the compactor.

Referring now to FIGS. 5 - 7, an advantage of the particular frame construction of this invention is that it makes possible a rather low outside corner placement of the elastomeric shear block type springs 16. This gives the compactor a relatively low profile, resulting in a relatively short moment arm existing between the point of ground contact of the compactor plate 14 and the spring members 16. This low profile also makes it possible for the compactor to be rotated back into a close stowed position against the boom for transport.

The frame construction also results in a downward load being applied at all four corners of the compaction plate 14.

The arm portions 34, 36, 38, 40 of the frame side members 26, 28 project downwardly below the springs 16 to serve as travel stops between the frame 12 and the compaction plate 14. Referring to FIG. 5, the frame 12 is only able to move the distance y towards the compaction plate 14. The travel stops 34, 36, 38, 40 are located below and inwardly of the springs 16. As a result, the springs 16 are not subjected to severe tension. FIG. 6 shows the spring 16 in maximum shear for the installation, and in a permissable amount of tension. FIG. 7 shows an uneven loading of the frame 12 which is normally a more severe condition with respect to distortion requirements of the springs 16 than the balanced loading condition shown by FIG. 6. However, as can clearly be seen by FIG. 7, owing to the location and arrangement of the springs 16 and the travel stops, the springs 16 on the non-contacting side of frame 12 are relieved in both tension and shear, whereas the springs 16 on the contacting side of frame 12 are loaded in essentially the same manner as they are loaded when a balanced load is applied on the frame 12 (i.e., the FIG. 6 condition). The beveled edges 41 contact end members 43 when the frame 12 and compaction plate 14 are relatively together. The sloping surfaces tend to cam these two members towards a centered position. They also limit the extent of horizontal displacement of plate 14 relative to frame 12 when these two members are relatively together and are loaded endwise.

While the invention has been shown in only one of its forms, it should be apparent to those skilled in the art that it is not thus limited, but is susceptible to various changes and modifications within the terms of the following set of claims.

Claims

What is claimed is:

1. In a vibratory compactor of a type including a mounting frame connectible to a loading boom which applies a downward force on the frame during use, a compaction plate, a vibratory unit centrally located on said compaction plate, said unit including a rotating eccentric weight and a coaxial hydraulic drive motor, and spring means connecting said compaction plate to said mounting frame, the improvement comprising:

said mounting frame comprising a pair of substantially identical, inverted U-shaped side plate members, and a pair of tubular cross members extending between opposed arm portions of said side plate members, said tubular cross members being rigidly connected at their ends to the arm portions of said plate members and being large enough in diameter to substantially stiffen said arm portions and maintain them substantially planar, and means for connecting said frame to a loading boom;

said compaction plate including four corner located mounting portions spaced outwardly from the stiffened arm portions of the side plate members;

said spring means comprising four elastomeric shear blocks disposed between the corner located mounting portions of said compaction plate and the stiffened arm portions of the side plate members, in line with said tubular cross members, said shear blocks being attached at their ends to the stiffened arm portions of said mounting frame, slightly radially outwardly of the location of connection of the tubular cross members to the stiffened arm portions, and to the corner located mounting portions of said compaction plate, but between their ends being free to distort in response to movement of the compaction plate relative to the mounting frame; and

said arm portions of said side plate members extending below said shear blocks and terminating in free ends which are normally spaced from the compaction plate but are close enough to the compaction plate that they contact it and limit the amount of displacement of the compaction plate relative to the mounting frame to an amount below the limits of distortion of the shear blocks.

2. The improvement of claim 1, wherein aligned pivot pin openings are formed through the bight portions of the mounting frame, for receiving a pivot pin used to connect the compactor to the loading boom, for pivotal movement about the axis of such pin; wherein a connector block is attached to said mounting frame closely adjacent a said pivot pin opening, said connector block including a delivery passageway having a first end to which a hydraulic fluid delivery conduit is connectible and a second end, and a return passageway having a first end to which a hydraulic fluid return conduit is connectible and a second end, a first length of flexible conduit connected to the second end of said delivery passageway and curving therefrom downwardly to the hydraulic drive motor of the vibratory unit, and connected to the inlet of the hydraulic drive motor, and a second length of flexible conduit connected to the second end of the return passageway in said connector block, and curving therefrom downwardly to said hydraulic drive motor and connected to the outlet of said hydraulic drive motor.

3. The improvement of claim 1, wherein the side plate members of the mounting frame have arch shaped opening which together define an arch-like tunnel which extends through the compactor, and wherein said vibratory unit is located within said tunnel, is detachably connected to said compaction plate, and is accessible for removal from the compaction plate without it being necessary to disconnect the mounting frame from the compactor plate.

4. The improvement of claim 1, wherein the displacement limiting free end portions of the side plate members have upwardly and outwardly sloping outer end parts, and wherein said compaction plate includes upwardly and outwardly sloping end members, whereby contact between the free end portions of the side plate members and the end members of said compaction plate will tend to cam the frame and the compaction plate towards a centered position, to in that manner limit the amount of horizontal displacement of the compaction plate relative to the frame when these two members are relatively together and are loaded endwise.