US3627371A

US3627371A - Hydraulically operated clamshell bucket

Info

Publication number: US3627371A
Application number: US2860A
Authority: US
Inventors: Roy O Billings
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-01-14
Filing date: 1970-01-14
Publication date: 1971-12-14
Anticipated expiration: 1988-12-14

Abstract

A clamshell bucket has complementary bowl sections pivotally supported from a head. Arms which are welded at one end to the outer edge of a first bowl section extend inwardly over the top of said bowl section where they are connected to the head on the same pivotal connection which connects the bowl section to the head, said arms having extensions. Other arms have one end welded to the outer edge of the second bowl section where they are pivotally connected to the head on the same pivotal connection which connects said second bowl section to the head, said arms having upward extensions in the nature of a bellcrank and there being an equalizer link pivotally connecting said upward extensions with the extensions of the arms for the first bowl section. An obliquely disposed hydraulic cylinder is pivoted on the horizontal axis to the head above the bucket, said cylinder having a piston rod which is pivotally connected to the arms of the first bowl section intermediate their length. Cutting lips at the sides of the bucket are flared downwardly and outwardly in a novel manner, when the bowl sections are open, to facilitate the digging of trenches and the like.

Description

United States Patent Roy 0. Billings 6621 W. Wisconsin Ave., Milwaukee, Wis.

[72] Inventor 53213 [21] Appl. No. 2,860 [22] Filed Jan. 14, 1970 [45] Patented Dec-14,1971

[54] HYDRAULICALLY OPERATED CLAMSHELL [50] Field of Search [56] References Cited UNITED STATES PATENTS 3,413,029 1 1/1968 Donovan 294/70 2,007,704 7/1935 Botten..... 37/186 3,103,753 9/1963 Takacs 37/187 Primary Examiner-Harvey C. Hornsby Assistant Examiner-Merle F. Mafiei Attorney-Morsell & Morsell ABSTRACT: A clamshell bucket has complementary bowl sections pivotally supported from a head. Arms which are welded at one end to the outer edge ofa first bowl section extend inwardly over the top of said bowl section where they are connected to the head on the same pivotal connection which connects the bowl section to the head, said arms having extensions. Other arms have one end welded to the outer edge of the second bowl section where they are pivotally connected to the head on the same pivotal connection which connects said second bowl section to the head, said arms having upward extensions in the nature of a bellcrank and there being an equalizer link pivotally connecting said upward extensions with the extensions of the arms for the first bowl section. An obliquely disposed hydraulic cylinder is pivoted on the horizontal axis to the head above the bucket, said cylinder having a piston rod which is pivotally connected to the arms of the first bowl section intermediate their length. Cutting lips at the sides of the bucket are flared downwardly and outwardly in a novel manner, when the bowl sections are open, to facilitate the digging oftrenches and the like.

PATENTEU DEC I '1 I97! SHEET 1 OF 4 INVENTOR ROY O. BILLINGS ATTORNEYS PATENTED 050141971 SHEET 2 BF 4 INVENTOR ROY 0. Bl LLI NGS ATTORNEYS INVENTOR 30v 0. Bl LLI NGS ATTORNEYS INVENTOR ROY O. BILLINGS bK f ATTORNEYS PATENTED DEC 1 4 I97! SHEET [1F 4 I I J I BACKGROUND OF THE INVENTION 1. Field of the Invention The improved clamshell bucket is adapted for use in the smaller sizes of earth-moving machines, and is particularly useful in excavators of the type having a dip stick or the like for supporting the bucket.

2. Description of the Prior Art In my U.S. Pat. No. 3,143,228 a clamshell bucket is disclosed wherein there is an hydraulic cylinder for each bowl member which controls the opening and closing movement. Where there are two hydraulic cylinders there is the possibility of hoses becoming tangled resulting from the necessity of having hydraulic hoses for each cylinder. Also, where there is an hydraulic cylinder for each bowl there is no assurance that the opening and closing movement of the two bowl sections will be equal, and there is a tendency to twist the bowls because the pressures are applied off center. In my copending application, Ser. No. 839,372, filed July 7, 1969, there is disclosed a construction having a single hydraulic cylinder for operating both bowl sections of the bucket. This type of construction is very suitable for larger sized buckets but it requires a fairly long hydraulic stroke and a substantial amount of oil. Bevin U.S. Pat. No. 2,755,946 discloses an hydraulically operated clamshell bucket wherein there is a single hydraulic cylinder assembly. However, here the cylinder is vertically disposed and it digs on the retraction of the cylinder rather than on the extension stroke, which is undesirable. Furthermore, in Bevin, with the vertical disposition of the hydraulic assembly, a great deal of headroom is required in operation due to the increased height of the bucket assembly when there is a cylinder projecting vertically thereabove. Also, a high bucket assembly tends to tip when pressure is applied from above, as is contemplated with the present invention.

SUMMARY OF THE INVENTION The present invention comprises a clamshell bucket having complementary bowl sections pivotally supported from a head which has spaced depending legs. An obliquely disposed hydraulic cylinder is pivoted on trunnions between the legs of the head and has its piston rod pivotally connected with the top of one of the bowl sections. Connections including an equalizer link operatively connect one bowl section with the other to cause both bowl sections to operate equally. In addition, the cutting lips at the sides of the bowl have portions which are flared downwardly and outwardly.

It is a general object of the present invention to provide an improved clamshell bucket wherein both bowl sections are operated by a single hydraulic cylinder supported obliquely by the head in a manner to provide for fast, efficient digging action on the extension stroke of the hydraulic cylinder assembly while employing a relatively short stroke with a minimum requirement for hydraulic fluid.

A further object of the invention is to provide a clamshell bucket in which there is a special equalizer link connection between the bowl sections, producing a mechanical advantage in operating that bowl section which is opposite the one to which the hydraulic cylinder assembly is directly connected.

A further object of the invention is to provide an improved clamshell bucket operated by a single hydraulic cylinder wherein there is improved means for causing both bowls to open and close uniformly and in perfect timing.

A further object of the invention is to provide an improved clamshell bucket in which portions of the cutting lips at the sides of the bowl sections are flared downwardly and outwardly in a novel manner, when the bowls are open, to provide efficient operation when digging trenches or the like.

A further object of the invention is to provide a bucket which has a relatively low outline so that it can be used in restricted locations under sidewalks or foundations, or to undercut a trench, and so that pressure can be applied from above during the digging cycle without causing the bucket to tip over.

With the above and other objects in view, the invention consists of the improved hydraulically operated clamshell bucket, and all of its parts and combinations, as set forth in the claims, and all equivalents thereof.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings, illustrating one complete embodiment of a preferred form of the invention, in which the same reference numerals designate the same parts in all of the views:

FIG. 1 is a side elevational view of the clamshell bucket with the bowls in closed condition;

FIG. 2 is a similar view showing the bowls in open condition, parts being broken away and shown in section;

FIG. 3 is a fragmentary sectional view taken on the line 3- 3 of FIG. 2;

FIG. 4 is a fragmentary elevational view looking at the end of one of the bowl sections;

FIG. 5 is an end view of the bucket while in closed condition; and

FIG. 6 is a sectional view taken approximately on the line 6-6 of FIG. 1.

DESCRIPT ION OF THE PREFERRED EMBODIMENTS Referring more particularly to the drawings, the bucket assembly includes an inverted U-shaped supporting head 28 having a top deck 29 by means of which it is supported from the end of the dipper stick of an earth moving device such as is illustrated in my copending application, Ser. No. 839,372. The deck has spaced depending legs 27.

THE BOWLS The bucket assembly includes

complementary bowl sections

30 and 31. Arms 32 positioned over the top of the bowl section 30 have outer ends welded or otherwise suitably secured to the outer edge of the bowl section as at 33. A pivot pin 34 extends through the upper projecting ends of the cutting lips 35 (referring to FIG. 1) at opposite sides of the bowl section 30, rotatably through the lower ends of the legs 27, and through the arms 32, the bucket being preferably fast on the ends of the pin 34. The arms 32 have lever extensions 36 which project inwardly beyond the pivot 34.

Arms 37 positioned over the top of the bowl section 31 have outer ends welded or otherwise suitably secured to the outer edge of the bowl section, as at 38. A pivot pin 39 extends through upper ends of the cutting lips 40 on opposite sides of the bowl section 31, rotatably through the lower ends of the legs 27, and through the inner ends of the arms 37, the ends of the pin 39 being fast to the bowl sections. The arms 37 have upward lever extensions 41 (referring to FIG. I) so that the arms are in the nature of bell cranks. An equalizer link 42 has one end pivotally connected between the upper ends of the extensions 41 of the arms 37 and its other end pivotally connected between the extensions 36 of the arms 32.

Mounted for pivotal movement on a pin 43, which extends between the legs 27 of the head, is a double-acting hydraulic cylinder 44 which normally assumes an angular position as shown in FIGS. 1 and 2. The cylinder has a piston rod 45 which projects angularly downwardly and has an outer end sleeve 45' through which a pin 46 rotatably extends, the sleeve being positioned between the arms 32.

As shown more clearly in FIG. 2, the

cutting lips

35 and 40 of the bowl sections on each side have

triangular portions

47 and 48 which are bent outwardly on

oblique lines

49 and 50 to produce the flare shown in FIGS. 3 and 4. Each of these triangularly shaped

flared portions

47 and 48 has one side formed by the line of

bend

49 or 50, one side formed by the cutting edge, and the third side formed by the end 52 of the cutting lip, i.e., the end which is most remote from the

pivot

34 or 39. This flare may be in any desired amount, but is preferably about 1 inch at the maximum near the lower outer comers of the cutting lips 47 and 48 (assuming the bowl sections are open). These outwardly flared cutting lips have cutting edges 51 as shown in FIGS. 3 and 4. The lower corner of each flared

portion

47 or 48 projects outwardly at least an inch farther than any other portion of the bucket side. Thus clearance is provided when digging a trench, rendering such digging action much more effective as there is a minimum of friction in moving the bucket in and out of the trench and while digging. Heretofore, it has been considered necessary to use side cutting teeth, like the end teeth 53, when it has been attempted to do digging with a clamshell bucket. With the novel flared portions 47. and 48 the necessity of using side teeth is eliminated.

OPERATION Clamshell buckets are customarily used for carrying. The present clamshell bucket, however, can dig as well as carry, and, therefore, is superior to the backhoe for many types of work. When operating the bucket while it is in the open position of FIG. 2, it can be lowered into the trench or other location and then the piston rod 45 is caused to be hydraulically extended. This produces closing movement of the bowl sections during the extension movement of the piston rod. During such closing movement the usual end teeth 53 perform a digging action and the special outwardly flared edges of the cutting

lips

47 and 48 also aid in the digging action, During extension of the piston rod 45 the equalizer link 42 acts to cause equal movement of the other bowl section 31. Due to the particular arrangement of the

arms

32 and 37 together with the equalizer link 32, the bowls are caused to open and close uniformly and with perfect timing. The particular linkage arrangement produces a mechanical advantage so that the bowls are capable of powerful digging action.

With this particular arrangement a single relatively inexpensive short stroke cylinder, with minimum oil requirements, may be employed for powering both bowl sections while producing a fast efficient digging action.

I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

What I claim is:

l. A clamshell bucket comprising a supporting head, complementary bowl sections, each having side cutting edges which meet along a generally upright line when the bucket is closed, one of said bowl sections having those upper corners which are nearest said upright line of meeting between the bowl sections pivotally connected to the head on a transverse pivot axis, and the other of said bowl sections having its upper comers which are nearest said upright line of meeting pivotally connected to the head on a transverse pivot axis which is spaced from and parallel with said first pivot axis, the major portion of each bowl section projecting laterally beyond its pivot axis with the head and having an outer upper edge spaced laterally outwardly from and extending in the same general direction as said pivot axis, the improvement comprising an obliquely disposed fluid pressure operated cylinder for one of said bowl sections only pivotally supported by said head on a transverse pivot axis and having an extensible piston rod which is pivotally connected to the top of said one bowl section between the outer edge of said bowl section and its pivot axis and a substantial distance below the pivotal connection between the cylinder and head when the bowl sections are closed, said piston rod being extended when the bowl sections are closed, and means for causing operation of the other bowl section including an equalizer link connecting said first bowl section with said other bowl section for transmitting operating movement thereto, said means and link being the sole means for operating said other bowl section and being disposed and arranged to cause equal movement of the two bowl sections when the cylinder is operated, there being an arm rigidly connected to and extending from the outer edge of one bowl section over the top of said section and having an extension which projects inwardly beyond the pivotal connection between said bowl section and the head and the piston rod being pivotally connected to said arm intermediate its length, there a so being an arm extending inwardly from the outer edge over the top of the other bowl section and rigidly connected thereto and having an extension which projects from the pivotal connection between said last-mentioned bowl section and the head, and the equalizer link being pivotally connected at one end to the last-mentioned extension and at the other end to the the lastmentioned extension and at the other end to the inward extension of the arm of the first bowl section, with said last pivotal connection being intermediate the pivotal connections between the two bowl sections and the head.

t t '0 t i

Claims

1. A clamshell bucket comprising a supporting head, complementary bowl sections, each having side cutting edges which meet along a generally upright line when the bucket is closed, one of said bowl sections having those upper corners which are nearest said upright line of meeting between the bowl sections pivotally connected to the head on a transverse pivot axis, and the other of said bowl sections having its upper corners which are nearest said upright line of meeting pivotally connected to the head on a transverse pivot axis which is spaced from and parallel with said first pivot axis, the major portion of each bowl section projecting laterally beyond its pivot axis with the head and having an outer upper edge spaced laterally outwardly from and extending in the same general direction as said pivot axis, the improvement comprising an obliquely disposed fluid pressure operated cylinder for one of said bowl sections only pivotally supported by said head on a transverse pivot axis and having an extensible piston rod which is pivotally connected to the top of said one bowl section between the outer edge of said bowl section and its pivot axis and a substantial distance below the pivotal connection between the cylinder and head when the bowl sections are closed, said piston rod being extended when the bowl sections are closed, and means for causing operation of the other bowl section including an equalizer link connecting said first bowl section with said other bowl section for transmitting operating movement thereto, said means and link being the sole means for operating said other bowl section and being disposed and arranged to cause equal movement of the two bowl sections when the cylinder is operated, there being an arm rigidly connected to and extending from the outer edge of one bowl section over the top of said section and having an extension which projects inwardly beyond the pivotal connection between said bowl section and the head and the piston rod being pivotally connected to said arm intermediate its length, there also being an arm extending inwardly from the outer edge over the top of the other bowl section and rigidly connected thereto and having an extension which projects from the pivotal connection between said last-mentioned bowl section and the head, and the equalizer link being pivotally connected at one end to the last-mentioned extension and at the other end to the inward extension of the arm of the first bowl section, with said last pivotal connection being intermediate the pivotal connections between the two bowl sections and the head.