hand tools :: essays research papers

Hand Tools and DevicesErgonomically oriented hand tool designMaintain a straight wristMaintain a straight wristBent Nose Pliers. Such tools permit grasping, cutting, or turning objective lenss while the wrist be in a relatively straight position. Hammer With Deviated Handle. The slightly bent handle maintains a straight wrist during the final impact position.Maintain a straight wristMaintain a straight wristSoldering Iron. The perpendicular bend of the head permits application of heat to a distal object while avoiding deviation of the wrist. Saws, Power Wrench, Knife. A perpendicular handle (pistol clutches) maintains a straight wrist during cutting, sawing, or rotary operations such as oil production or nut tightening.Maintain a straight wristProvide an optimal grip spanCylindrical Handle. A tool for rotary natural process on a horizontal work piece maintain the wrist in a straight position. Excessive grip span does not entrust optimal application of force and imposes undue s tress upon the joints.Avoid tissue compressionProtect against heat, cold, vibration extremesExcessively thin or short handles example small surface areas which in turn cause excessive pressure on tissues, leading to loss of local circulation.Circulation is also affected by opposite factors such as vibration and temperature extremes from the tool of from the immediate environment. Gloves and insulating materials are used as protective devices.Second handleExpanding springAn additional handle for ply tools, located near the trend end, helps support a heavy tool, resistance to excessive torque, and safe placement of the tool on to the work piece. Expanding spring on handles opens handles without stressful operator effort.Thumb stopGlovesA thumb stop improves stability, increases thrust force, and avoids slippage.Gloves may be unavoidably used in inclement circumstances. Compensations mustiness be made, when gloves are used, for a diminished grip force, diminished manual dexterity, and increased bulkiness which requires large handle dimensions.General considerationsLoss of gripThe available assignment of the hands. Hands, when used with a tool, may be classified into the holding hand and the assisting hand. Dropped Tool. Power saw dropped on foot.Loss of gripLoss of gripSlipping Hazard. Hand slips on to unguarded surface. Curved Knife Guard.Loss of gripLoss of gripKnife. Ring guard. limit for one finger. Knife. Handle guard. Enclosure for all fingers.Balanced power toolSecond handleHandle located at center of gravity. A second handle near the front of a large tool allows added control. A second handle will also aid in resisting high torque forces.Crushing in amongstAccidental activationHandle Stops. Handle stops allowing at least 2.5 cm clearance prevent crushing fingers between handles.