Thumb for scooping tool arm

A tool arm assembly comprising an elongated tool arm having an outer free end equipped with a scooping tool and a thumb, said thumb comprising a pair of generally parallel U-shaped spaced-apart lateral forks defining an opening therebetween devoid of any structural elements and forming a tool arm channel extending between said forks, said forks having inner ends, a pivot member pivotably attaching said forks inner ends to the tool arm outer free end for pivotal movement of said thumb about a pivotal axis, and outer ends opposite said inner ends, said forks being significantly curved about a common axis and defining a concave scooping side, said scooping tool selectively co-operating with said thumb and comprising an inner end pivotably attached to said pivot member for pivotal motion relative to said tool arm outer free end, an outer end opposite said inner end, and a scooping side in pivotal facing register with said thumb for grasping objects between said thumb and said scooping tool scooping side, said tool arm assembly further comprising a first power actuator operatively attached to said tool arm and to said thumb for selectively pivoting said thumb relative to said scooping tool and to said tool arm, said tool arm assembly further comprising a second power actuator operatively attached to said tool arm and to said scooping tool for selectively pivoting said scooping tool relative to said thumb and to said tool arm;

• wherein said pivot member enables said thumb and said scooping tool to be independently pivotable relative to one another and to said tool arm about parallel axes, and wherein said thumb is pivotable between a first limit position in which said forks outer end engages said scooping tool scooping side and said scooping tool scooping side is in facing register with said forks scooping side, and a second limit position in which said thumb is pivoted away from said scooping tool scooping side and said tool arm is embedded in said opening between said thumb forks and extends within said tool arm channel, with a transverse hollow opening being defined between said forks and said scooping tool scooping side in said first limit position of said forks for transverse, uncompressed engagement of objects carried therein, and with a significant portion of said thumb extending beyond a surface of said tool arm that is in pivotal facing register with said scooping tool scooping side when said thumb is in said second limit position.

A vehicle comprising:

• a frame movable over ground;
• a boom pivotably attached to said frame;
• an elongated tool arm having an inner end pivotally attached in said boom and an outer free end opposite said inner end and equipped with a scooping tool and a thumb, said thumb comprising a pair of generally parallel U-shaped spaced-apart lateral forks defining an opening therebetween devoid of any structural elements and forming a tool arm channel extending between said forks, said forks having an inner end pivotably attached to the tool arm outer free end and an outer end opposite said inner end, said forks being significantly curved about a common axis, said scooping tool selectively co-operating with said thumb and comprising an inner end pivotably attached to the tool arm outer free end, an outer end opposite said inner end, and a scooping side in pivotal facing register with said thumb for grasping objects between said thumb and said scooping tool scooping side;
• a first actuator operatively attached to said tool arm and to said thumb for selectively pivoting said thumb relative to said scooping tool and to said tool arm;
• a second actuator operatively attached to said tool arm and to said scooping tool for selectively pivoting said scooping tool relative to said thumb and to said tool arm;
• a third actuator operatively attached to said boom and to said tool arm, for selectively pivoting said tool arm relative to said boom;
• a fourth actuator operatively attached to said vehicle frame and to said boom, for selectively pivoting said boom relative to said vehicle;
• wherein said thumb and said scooping tool are independently pivotable about parallel axes, and wherein said thumb is pivotable between a first limit position in which said forks outer end engages said scooping tool scooping side, and a second limit position in which said thumb is pivoted away from said scooping tool scooping side and said tool arm is embedded in said opening between said thumb forks and extends within said tool arm channel, with a transverse hollow opening being defined between said forks and said scooping tool scooping side in said first limit position of said forks for transverse, uncompressed engagement of objects carried therein, and with a significant portion of said thumb extending beyond a surface of said tool arm that is in pivotal facing register with said scooping tool scooping side when said thumb is in said second limit position.