US2834128A - Self-cleaning digging wheel buckets - Google Patents

Description

May 13, 1958 F. F. KOLBE 2,834,128

SELF-CLEANING DIGGING WHEEL BUCKETS Original Filed Oct. 1, 1952 INVEN TOR.

EM X1344, 19M

Unite States SELF-CLEANING DIGGING WHEEL BUCKETS Frank F. Kolbe, Winnetka, 11L, assignor to The United Electric Coal Companies, Chicago, 111., a corporation of Delaware Original application October 1, 1952, Serial No. 312,517. and this application May 23, 1956, Serial No.

4 Claims. (Cl. 37-189) The present invention relates to wheel excavators of the bucket wheel type and, particularly, to improved buckets for digging wheels. The present application is a division of my copending application, Serial No. 312,517, filed October 1, 1952, now abandoned, and relates to improvements in self-cleaning buckets of the character disclosed in my copending application, Serial No. 585,335, filed May 16, 1956, a continuation-in-part of my said application, Serial No. 312,517.

In the utilization of conventional digging wheels, the

structure of which is well known, the wheel is rotated to force the buckets at the periphery thereof into the earth to scoop up earth materials. The material is carried upwardly by the buckets and, at approximately the top point of bucket rotation, the material is supposed to gravitate out of the buckets and onto a suitable conveyor or the like for removal and disposal. However, when excavating earth materials such as mud, clay and the like, the material tends to stick to and in the buckets even at the top point of bucket rotation so that upon subsequent engagement of the buckets with the earth, little or no excavation can occur. With other types of earth materials, there is a gradual but consistent and fairly rapid build-up of earth materials on the surface of the buckets which eventually renders the buckets useless. In either case, operation of the wheel must be stopped and the buckets must be cleaned manually.

The primary object of the present invention is to provide improved buckets for digging wheels, which buckets are automatically self-cleaning so as to prevent retention of relatively sticky or gummy earth materials in the buckets and to prevent gradual build-up of earth ma-.

terials in the buckets.

According to the present invention, 1 provide an improved bucket for digging wheels having at least a portion of the rear or back wall thereof defined by a flexible and movable mat. By providing the mat in the rear wall of the rigging wheel bucket with clearance at the sides thereof, the creation of a suction or vacuum pressure condition in the bucket, which would prevent discharge of earth materials, is substantially prevented. The mat is flexible and movable so that when the bucket reaches the top of its rotation, the mat moves inwardly to reduce suction, to force material out of the bucket and to break up any materials tending to adhere to the surfaces of the bucket in the path of mat movement. Accordingly, it will be appreciated that buckets provided with the aforesaid mat are rendered automatically self cleaning.

In addition to the foregoing, the mat accommodates the escape of quantities of water and other fluids so that the bucket is adapted to excavate a full measure of earth material. Also, the mat is responsive to vibrations of the wheel so as to break up and discharge earth materials in the bucket and to prevent gradual build-up of materials on the walls of the bucket.

It is the object of the present invention to provide an improved mat for self-cleaning buckets of the character ward edge or wide end thereof, the bucket is flared out- 2,334,128 Patented May 13, 1953 as i described comprising a sheet of rubber or the like pivotally attached to the bucket at its ends and with its sides being free for movement and for venting of liquids and suction conditions.

Stated more completely, the object of the invention is to provide an improved self-cleaning digging wheel bucket comprising a metallic bucket having a large opening in the rear wall thereof and a flexible, movable mat closing the opening, the mat comprising a sheet of flexible material mounted for movement with respect to the remainder of the bucket to facilitate the discharge of earth materials.

Other objects and advantages of the present invention will become apparent in the following detailed description of a preferred embodiment of the invention, wherein reference is made to the accompanying drawing, in which:

Figure 1 is a side elevation of a digging wheel and its associated apparatus; and

Figure 2 is a vertical sectional view, on an enlarged scale, of a preferred embodiment of a digging wheel bucket formed according to the present invention. The dotted line position of mat 50 is intended to show a discharge position of the mat when the excavating bucket is in an upside-down position from that of Fig. 2. The dot-dash outline of mat 5t shows one position of the mat following discharge and as the excavating bucket is rotating to its lower, excavating position.

Referring now to Figure 1, the present invention is particularly adapted to excavating apparatus comprising, generally, a digging wheel 10 rotatably supported at the free end of a digging ladder 12. The digging wheel 113 is provided with a plurality of buckets 14 at its periphery. Each of the buckets is provided at its forward edge with teeth 15 adapted to cut into a bank of material to be excavated by the excavating apparatus and is otherwise formed as described hereinafter. In operation, the digging wheel is rotated in the direction indicated by the arrow in Figure 2 to effect an upward cutting action against a bank of material. The teeth and leading edge of the bucket 14 cut into the material and force material into the bucket 14. As the buckets continue to rotate toward the top center of the wheel, the open bottoms thereof are closed by a stationary plug 16 adapted to retain the earth materials within the buckets until the buckets pass upwardly to a desired point. As the buckets pass the upper edge of the plug 16, the material therein gravitates onto a slope sheet 18 or like means which is adapted to direct the material onto a slope sheet roller 26) which transfers the material from the slope sheet 18 onto a conveyor 22. The conveyor 22 conveniently leads to a point of disposal.

The digging wheel buckets 14, individually, that is as formed separately of the wheel, each conventionally comprise a metallic three-walled bucket, preferably a unitary casting, including a pair of side walls 24 and a rear or back wall 26 joining the side walls. The side walls 24,

as viewed in elevation, are each generally beak-shaped, or are in the form of one-half of a crescent, and the rear wall 26 is arcuate to conform to the outer peripheral margins of. the side walls. The buckets are mounted on the wheel with the narrow or generally pointed end thereof extending within the confines of the. wheel and the wide or openend thereof extending radially beyond the periphery of the wheel. Each bucket is suitably secured to the wheel, preferably by welding portions of the side walls to the rims of the wheel and by welding the narrow or pointed endof the bucket to a rod 28 secured to and extending transversely of the wheel. At the forwardly to provide an entry opening, and the plurality of teeth are suitably attached to the leading or forward edge of the bucket to cutinto andbreakup the earth materials.

According to the present invention, conventional bucket design may be adhered to, but, as shown in Fig: ure' 2, an aperture or opening is providedthe rear wall 26* of the bucket, which opening is closed by a mat 32. The mat 32 is flexible and is so mounted as to be capable of movement with respect to the rear wall of the bucket. The opening 30 may be formed of any desired size, but preferably is ofa size corresponding at least to approximately 75% of the area of the rear wall. The opening is preferably spaced from the forward edge of the wheel so as not to weaken the leading edge and tooth supporting portion of the bucket. While I have shown the aperture or opening 30 as being provided only in the back or rear wall of the bucket it will be appreciated as the description proceeds that the opening may extend into the side walls or the bucket if desired. Accordingly, it willbe appreciated that the bucket of the present invention comprises a metallic bucket having a portion of atleast the back wall hereof defined by a flexible and movable mat. V

The mat 32 may be formed of various flexible sheet. materials, and a preferred form thereof is disclosed in Figure 2 as comprising a rectangular sheet 50 of rubber or rubber-like material. The sheet 50 may be fabricated in any customary manner and may include fabric or metallic reinforcing members. In this respect, I dontemplate that fabric reenforced conveyor belting will be a practical material.

To secure the mat to the bucket within the opening 30, a plurality of U-shaped brackets 38 are secured to the bucket at each end of the opening in spaced parallel relation with the bight portion of the U spaced from the edge of the opening. The legs of each bracket engage the opposite surfaces of the bucket and are secured thereto, suitably by welding. The bight portions of the U- shaped brackets comprise hinge leaves or the like adapted for the reception and support of a mounting pin, pintle pin, or rod 40 at each end of the opening 30. At the opposite ends thereof, the rubber sheet is suitably stepped or serrated to provide spaced hinge portions 52 adapted to extend between adjacent U-shaped brackets 38 for the passage of the pintle pin 40. Preferably, metallic sleeves 54 are positioned within, preferably by molding the same in, the hinge portions 52 of the sheet 50 for reception and guidance of the pins 40. If desired, the pins 40' may suitably be secured to the respective brackets 33, as by welding. Further, the pins or rods 40 may be positioned in alignment with, or in the same plane as, the back wall of the bucket to prevent disassociation of the pins. Also, if desired, the assembly of the mat, the brackets and the pins or rods may be made separately and then secured as a unit to the bucket. The sheet material 50 is not connected to the bucket at the sides of the opening 30 so that the same will have freedom of movement in response to actuation of the wheel.

In use of the buckets, the mat at its free edges,'which are spaced from the bucket proper, will provide a vent to accommodate discharge of fluids and to prevent the occurrence of a vacuum or suction condition in the buckets. In addition, the sheet 50 will be capable of movement in response to gravity as the wheel is rotated and will also be subject to wheel vibration to insure discharge of materials from the buckets and to prevent the accumulation of materials on the surfaces of the buckets. Since the mat area will remain clean, the surfaces of the side walls and the forward portion of the back wall of each bucket will be rendered self-cleaning due to the fact that upon entry of the bucket into the earth any slight amount of material that may accumulate on such surfaces will be forced intothe mat portion of the bucket. The buckets are readily adapted for excavation of loose materials, such as sand and gravel, without the possibility of inefiicient excavating resulting from loss of materials through the mat.

In view of the foregoing, it is to be appreciated that the mat, which is flexible in all directions and of a length greater than the shortest distancebetween the front and rear edges of the opening in the back of the bucket, is freely movable into and out of the said opening and does not overlie or underlie any part of the bucket proper; Because of these facts, there is no portion of the that that will become rigidified or that can in effect become bonded or confined against a surface of the bucket proper due to the repeated packing of earth, mud, clay and the like into the bucket. Further, as the wheel is rotated, each mat in gravitating into the bucket falls rapidly downwardly to the substantial extent accommodated by its length (see Fig. 2) whereupon it is brought up short and rebounds upwardly with a snap action resulting in flexing and shaking of the mat in all directions. to cleanthe same. Such. action insures that" the mats areautornatically self-cleaning. Furthermore, in falling or gravitating downwardly and in being flexed and shaken, the side edges of the mat perform a scraping action in relation to the side walls of the bucket, and this function, coupled with the self-cleaning function of the mat, renders each bucket automatically self-cleaning.

With respect to the structure of the digging wheel, it is to be appreciated that the buckets, particularly as having open backs, cannot provide laterally thereof the degree of rigidity essential in excavating wheels, and itisnecessary therefore to tie the two rims of the wheel to.-'- gether. To this end, I provide a reinforcing bar or red 42 extending between the rims of the wheel 10, over the opening 30 and across the back of each bucket more or less in abutting relation thereto. The primary purpose of the rods 42 is for wheel strength and rigidity,- but each also acts to prevent distention of the mat.- The rods 42 of course are not part of the bucket proper, and being cylindrical, present such minute area to the mat as not in any way to interfere With the automatic self-cleaning, functions of the mat as previously described,

From the foregoing, it will be appreciated that the present invention provides an improved digging wheel bucket for excavating apparatus wherein the bucket is: self-cleaning and insures eliicient use of the apparatus.v

While I have described what I regard to be a preferred embodiment of my invention, it will be apparent thatvarious changes, rearrangements and modifications may be made therein without departing from the: scope of the invention, as defined by the appended claims.

I claim:

1. In a digging wheel bucket having spaced generally parallel side walls and an arcuate back wall joining theside walls, the back wall having an opening therein conn stituting the major portion of the back wall, the improve-- ment comprising a sheet of flexible material mounted in said opening, said sheet being of a width less than the width of said opening and of a length substantially greater than the shortest distance between the front and rear edges of said opening, said sheet being hingedly connected solely at its forward and rearward edges to said: back wall adjacent the front and rear edges of said opening, said sheet at the side edges thereof being freely spaced from and freely movable with respect to the side edges of said opening, said sheet being freely spaced from and not overlying or underlying the walls and surface portions of the bucket, said sheet being flexible in all directions and freely movable into and out of said opening.

2 A self-cleaning digging bucket for rotatable excavab ing wheels comprising a bucket including spaced generally parallel side walls and an arcnate back wall joining said ide walls and extending in a direction inwardly of'thej wheel from the lip to the tail end thereof, said back wall having a large generally rectangular opening therein constituting the major portion of the area of the back wall and leaving a relatively short back wall portion extending between said side walls at the lip end thereof, and a sheet of flexible rubber-like material disposed in said opening and comprising substantially the remainder of the back wall of the bucket, said sheet being hingedly connected at its for- Ward and rearward edges only to said back wall in spaced relation to the forward and rearward edges of said opening, said sheet being of a width less than the spacing between the side edges of the said opening, whereby the side edges of said sheet are freely spaced from and freely movable with respect to the side edges of said opening, said sheet being freely spaced from and not overlying or underlying the walls or surface portions of the bucket proper, said sheet being flexible in all directions and of a length substantially greater than the shortest distance between the front and rear edges of said opening, said sheet being freely movable into and out of said opening, said sheet when the bucket is disposed with its back wall down freely gravitating into said opening and into the plane of said back wall substantially to conform to the arcuate curvature of said back wall, said sheet when the bucket is disposed with its back wall up freely gravitating a substantial distance downwardly into the bucket toshake dirt, mud, clay and the like free of the bucket and said sheet and to effect a relative scraping action with respect to said side walls to clean the same.

3. In a digging Wheel bucket having spaced generally parallel side walls, a lip portion joining said side walls at the lip end thereof and a tail portion joining said side walls at the tail end thereof in spaced relation to said lip portion, saidsidewalls and lip and tail portions defining an opening, the improvement comprising a mat of flexible material hingedly connected solely at its forward and rearward edges to said lip and tail portions respectively and constituting the greater portion of the back wall of the bucket, said mat being of a width substantially the width of said opening and of a length substantially greater than the straight-line distance between said lip and tail portions and being freely movable into and out of said opening.

4. A self-cleaning digging wheel bucket for excavating apparatus comprising a bucket including spaced generally parallel side walls having an arcuate peripheral edge, a back wall portion joining the peripheral edges of said side walls at the lip end of the bucket, and a back wall portion joining the peripheral edges of said side walls at the tail end of the bucket in spaced relation to said back wall lip portion, said sidewalls and said lip and tail portions defining an opening, and a sheet of flexible rubber-like material of a width less than the distance between said side walls and of a length greater than the shortest distance between said back wall portions, said sheet being hingedly connected solely at its ends to the bucket in spaced rela tion respectively to said back wall portions, said sheet at its side edges being freely spaced from and freely movable relative to said side walls, said sheet being spaced from and not overlying or underlying any portion of the bucket and being freely movable into and out of said openmg.

References Cited in the file of this patent UNITED STATES PATENTS 885,049 Holcomb Apr. 21, 1908

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