Abstract: The present invention provides a solenoid including an electrically conductive coil and a plunger located axially within the coil. The plunger is moved in an axial direction within the coil when the coil is energized. The motion of the plunger in the axial direction in the coil at a position such that, when the plunger is moved to the position by energizing the coil, the force exerted by the plunger is linear with respect to the electric power supplied to the coil.The present invention also provides yarn tensioning apparatus employing a number of yarn tensioning devices using such a solenoid. A control system, including a special device for sensing the tension exerted on the yarn, allows each of the yarn tensioning devices in the apparatus to be individually and automatically controlled. The present invention also provides a method for individually controlling the tension exerted on each yarn either manually or automatically.

Abstract: The present invention provides a solenoid including an electrically conductive coil and a plunger located axially within the coil. The plunger is moved in an axial direction within the coil when the coil is energized. The motion of the plunger in the axial direction in the coil at a position such that, when the plunger is moved to the position by energizing the coil, the force exerted by the plunger is linear with respect to the electric power supplied to the coil.The present invention also provides yarn tensioning apparatus employing a number of yarn tensioning devices using such a solenoid. A control system, including a special device for sensing the tension exerted on the yarn, allows each of the yarn tensioning devices in the apparatus to be individually and automatically controlled. The present invention also provides a method for individually controlling the tension exerted on each yarn either manually or automatically.

Abstract: Methods and apparatus are provided for transporting a disabled person in a carrying means. One embodiment of the apparatus includes a dual-track structure for supporting a hoist and trolley which are controlled by the disabled person. In a further embodiment, the structure is designed to be supported by a floor and ceiling together, or by a floor alone, and is adjustable to accommodate rooms of different dimensions. A still further embodiment of the invention includes mechanical and electronic safety means for the hoist which senses a malfunction and provides an appropriate response thereto, such as sounding an alarm and/or lowering the hoist at a specific pre-programmed location and at a controlled descent rate. The embodiments may be used independently or in concert in accordance with the invention. One method of the invention comprises transporting the disabled person utilizing the dual-track structure controlled by the disabled person.