Loader linkage with jointed lift arms

Claim 2

In an end loader having a mobile frame and a bucket, an operating linkage for the bucket comprising, in combination: a pair of forwardly extending lift arms forming a secondary boom mounted on aligned main pivots which are adjacent the upper front extremities of the sides of the frame; a pair of lifting jacks mounted on the sides of the frame on aligned pivots which are below the main pivots, said lifting jacks being pivotally connected to the lift arms so that extension of the jacks swings the secondary boom on the main pivots from a downwardly inclined position to an upwardly inclined position; a pair of bell cranks pivoted on aligned fulcrums at the free end of the secondary boom, said bell cranks having forwardly extending first arms that form a primary boom which is connected to lower pivots on the bucket, and said bell cranks having short second arms; a pair of primary hydraulic jacks mounted on the sides of the frame on aligned primary jack pivots which are adjacent the main pivots, said primary jacks being pivotally connected to the second bell crank arms so that operation of said primary jacks swings the primary boom between a first position generally aligned with the secondary boom and a second position above and generally perpendicular to said secondary boom, said secondary boom, said primary jacks, said second bell crank arms and the frame between the main pivots and the primary jack pivots forming a four bar linkage so that bucket thrust is applied to the frame through said main pivots and said primary jack pivots; and bucket control means including dumping jacks which are connected to upper bucket pivots to control the aspect of the bucket with respect to the primary boom.

Claim 3

The combination of claim 1 in which the bucket control means includes control levers which are pivoted on fulcrums that are generally aligned with the bell crank fulcrums, said levers having long arms pivotally connected to the dumping jacks, and said levers having short arms, and tag links pivoted to said short arms and to the frame.

Claim 4

The combination of claim 2 in which the short bell crank arms and the short control lever arms are substantially the same length, the length of the tag links is substantially equal to the extended length of the primary jacks, and the tag links are connected to the frame by means of the primary jack pivots.

Claim 5

The combination of claim 2 in which the primary boom, the dumping jacks, the long arms of the control levers, and the bucket between the lower and upper pivots form a four bar linkage.

Claim 6

The combination of claim 4 in which the distance between the lower and upper bucket pivots is about equal to the length of the long control lever arms, and the retracted length of the dumping jacks is about equal to the length of the primary boom.

Claim 7

The combination of claim 1 which includes stops on the secondary boom that are abutted by the second bell crank arms in the first position of the primary boom, whereby bucket thrust in said first position is transmitted to the frame almost entirely through the primary and secondary booms.

Claim 8

The combination of claim 1 in which the length of the primary boom is about 1/2 the length of the secondary boom.

Claim 9

The combination of claim 1 in which the bucket control means includes control levers which are pivoted on fulcrums that are generally aligned with the bell crank fulcrums, said levers having long arms pivotally connected to the dumping jacks, and said levers having short arms, and tag links pivoted to said short arms and to the frame, the length of the primary boom is about 1/2 the length of the secondary boom, and in which the primary boom, the dumping jacks, the long arms of the control levers, and the bucket between the lower and upper pivots form a four bar linkage.

Claim 10

The combination of claim 8 in which the tag links are pivotally connected to the frame on pivots that are extensions of the primary jack pivots.

Claim 11

The combination of claim 8 which includes stops on the secondary boom that are abutted by the second bell crank arms in the first position of the primary boom, whereby bucket thrust in said first position is transmitted to the frame almost entirely through the primary and secondary booms.

Claim 12

In an end loader having a mobile frame and a bucket, an operating linkage for the bucket comprising, in combination: a pair of forwardly extending lift arms forming a secondary boom mounted on aligned main pivots which are adjacent the upper front extremities of the sides of the frame; a pair of lifting jacks mounted on the sides of the frame on aligned pivots which are below the main pivots, said lifting jacks being pivotally connected to the lift arms so that extension of the jacks swings the secondary boom on the main pivots from a downwardly inclined position to an upwardly inclined position; a pair of bell cranks pivoted on aligned fulcrums at the free end of the secondary boom, said bell cranks having forwardly extending first arms that form a primary boom which is connected to lower pivots on the bucket, and said bell cranks having short second arms; a pair of primary hydraulic jacks mounted on the sides of the frame on aligned primary jack pivots, said primary jacks being pivotally connected to the second bell crank arms so that operation of said primary jacks swings the primary boom between a first position generally aligned with the secondary boom and a second position above and generally perpendicular to said secondary boom, bucket control levers pivoted on fulcrums that are generally aligned with the bell crank fulcrums, said levers having a long arm and a short arm; hydraulic dumping jacks pivotally connected to the long arms of the bucket control levers and to upper pivots on the bucket, the primary boom, the dumping jacks, the long arms of the bucket control levers, and the bucket between the lower and upper pivots forming a four bar linkage; and tag links pivotally connected to the short arms of the bucket control levers and to the frame.

Claim 13

In an end loader having a mobile frame and a bucket, an operating linkage for the bucket comprising, in combination: a pair of forwardly extending lift arms forming a secondary boom mounted on aligned main pivots which are adjacent the upper front extremities of the sides of the frame; a pair of lifting jacks mounted on the sides of the frame on aligned pivots which are below the main pivots, said lifting jacks being pivotally connected to the lift arms so that extension of the jacks swings the secondary boom on the main pivots from a downwardly inclined position to an upwardly inclined position; a pair of bell cranks pivoted on aligned fulcrums at the free end of the secondary boom, said bell cranks having forwardly extending first arms that form a primary boom which is connected to lower pivots on the bucket, and said bell cranks having short second arms; a pair of primary hydraulic jacks mounted on the sides of the frame on aligned primary jack pivots, said primary jacks being pivotally connected to the second bell crank arms so that operation of said primary jacks swings the primary boom between a first position generally aligned with the secondary boom and a second position above and generally perpendicular to said secondary boom, bucket control levers pivoted on fulcrums that are generally aligned with the bell crank fulcrums, said levers having a long arm and a short arm; hydraulic dumping jacks pivotally connected to the long arms of the bucket control levers and to upper pivots on the bucket, the primary boom, the dumping jacks, the long arms of the bucket control levers, and the bucket between the lower and upper pivots forming a four bar linkage; and tag links pivotally connected to the short arms of the bucket control levers and to the frame.

Claim 14

The combination of claim 11 in which the dumping jacks when retracted are about the same length as the primary boom, and the length of the long arms of the bucket control levers is about equal to the distance between the lower and upper pivots on the bucket.

Claim 15

The combination of claim 11 in which the bucket control lever fulcrums are coaxial with the bell crank fulcrums, the short bell crank arms and the short lever arms are substantially the same length, the length of the tag links is about equal to the extended length of the primary jacks, and the tag links are pivoted to the frame on extensions of the primary jack pivots.

Claim 16

The combination of claim 11 which includes stops on the secondary boom that are abutted by the second bell crank arms in the first position of the primary boom, whereby bucket thrust in said first position is transmitted to the frame almost entirely through the primary and secondary booms.

Claim 17

The combination of claim 11 in which the length of the primary boom is about one-half the length of the secondary boom.

Claim 18

In an end loader having a mobile frame and a bucket, an operating linkage for the bucket comprising, in combination: a first four bar linkage that includes a secondary boom and a primary jack pivotally mounted on the frame on adjacent mounting pivots, and a short arm of a bell crank which has its fulcrum on a pivot on the end portion of the secondary boom, said first four bar linkage including the frame between said adjacent pivots; a second four bar linkage that includes a long arm of said bell crank which constitutes a primary boom on which the bucket is pivotally mounted by means of lower pivots, a bucket control arm pivotally mounted on the secondary boom adjacent the bell crank fulcrum, and a dumping jack pivotally mounted on said control arm and pivotally connected to the bucket by means of upper pivots, said second four bar linkage including the bucket between said lower and upper pivots; and a lifting jack pivotally connected to the frame and to the secondary boom.

Claim 19

In an end loader having a mobile frame and a bucket, an operating linkage for the bucket comprising, in combination: a first four bar linkage that includes a secondary boom and a primary jack pivotally mounted on the frame on adjacent mounting pivots, and a short arm of a bell crank which has its fulcrum on a pivot on the end portion of the secondary boom, said first four bar linkage including the frame between said adjacent pivots; a second four bar linkage that includes a long arm of said bell crank which constitutes a primary boom on which the bucket is pivotally mounted by means of lower pivots, a bucket control arm pivotally mounted on the secondary boom adjacent the bell crank fulcrum, and a dumping jack pivotally mounted on said control arm and pivotally connected to the bucket by means of upper pivots, said second four bar linkage including the bucket between said lower and upper pivots; and a lifting jack pivotally connected to the frame and to the secondary boom.

Claim 20

The combination of claim 16 in which the bucket control arm is a long arm of a lever, and said lever also has a short arm, and in which a tag link is pivotally connected to said short arm and to the frame adjacent the mounting pivot for the primary jack.

Claim 21

The combination of claim 16 in which the pivotal mountings for the lever and for the control arm are coaxial.

Claim 22

The combination of claim 18 in which the pivotal connection of the tag link to the frame is coaxial with the mounting pivot for the primary jack.

Claim 23

The combination of claim 19 in which the short bell crank arm and the short lever arm are substantially the same length, and the length of the tag link is substantially equal to the extended length of the primary jack.