Abstract: A gate valve for use in controlling the level of a dam has a first plate with an aperture on an upstream face of the dam and a movable plate on the upstream side of the fixed plate, with apertures sixed and dimensioned to operate as a scissors when the movable plate is urged in a linear motion parallel to fixed plate. One or more edges of the apertures in the plates are provided with a sharp edge or a serrate edge oriented to sever obstructing object present in the apertures when the valve is transitioning from an open position to a closed position.

Abstract: A gate valve for use in controlling the level of a dam has a first plate with an aperture on an upstream face of the dam and a movable plate on the upstream side of the fixed plate, with apertures sized and dimensioned to operate as a scissors when the movable plate is urged in a linear motion parallel to fixed plate. One or more edges of the apertures in the plates are provided with a sharp edge or a serrate edge oriented to sever obstructing object present in the apertures when the valve is transitioning from an open position to a closed position.

Abstract: An energy absorbing device suitable for wearing by humans, or for use in a prosthetic device or robot is provided. The device including support structures which may conform to the contours of limbs, and have the capability of being removeably attached to the limbs. Plates are attached, either fixedly or slideably, to the support structures and adjacent ends of plates may be joined with a flexible link. As the limbs flex at a joint, the slideably attached plate slides to accommodate the rotational motion between the limbs at the joint.

Abstract: An energy absorbing device suitable for wearing by humans, or for use in a prosthetic device or robot is provided. The device including support structures which may conform to the contours of limbs, and have the capability of being removeably attached to the limbs. Plates are attached, either fixedly or slideably, to the support structures and adjacent ends of plates may be joined with a flexible link. As the limbs flex at a joint, the slideably attached plate slides to accommodate the rotational motion between the limbs at the joint.

Abstract: An energy absorbing device suitable for wearing by humans, or for use in a prosthetic device or robot is provided. The device including support structures which may conform to the contours of limbs, and have the capability of being removeably attached to the limbs. Plates are attached, either fixedly or slideably, to the support structures and adjacent ends of plates may be joined with a flexible link. As the limbs flex at a joint, the slideably attached plate slides to accommodate the rotational motion between the limbs at the joint.

Abstract: A work dolly affording a mechanic access to a vehicle from the top end. The dolly is foldable into a small assembly that takes very little floor space and is provided with a wheeled support that is operable in all modes of operation. Foldable legs lockably coact with an adjustable foldable worker support to provide a compact portable unit when in the storage mode of operation. The worker support portion may be used by the mechanic in either a sitting or prone position.