Abstract: The present invention relates to a front plate for an ion source that is suitable for an ion implanter. The front plate according to the invention comprises obverse and reverse sides, an exit aperture for allowing egress of ions from the ion source that extends substantially straight through the front plate between the obverse and reverse sides, and a slot penetrating through the front plate from obverse side to reverse side at a slant for at least part of its depth, the slot extending from a side of the front plate to join the exit aperture. The slot is slanted to occlude line of sight into the ion source when viewed from in front, yet provides an expansion gap.

Abstract: In a riding concrete finishing trowel, a stabilizer is operatively disposed between the frame and either the gearbox or a structure that is coupled to the gearbox so as reduce the effects of rotor assembly vibration on the trowel. In one embodiment, the stabilizer takes the form of a gas spring located between the frame and the pitch control post. The stabilizer may be located relatively close to the top of the pitch control post so as to take advantage of the mechanical advantage offered by the spacing between that location and the gearbox.

Abstract: A portable vibratory screed includes a blade that is connected to a handle constructed to be manipulated by an operator. Nodes of minimum vibrational amplitude are formed at specific locations along the length of the blade when the exciter is driven at a rated operating speed. A site level and/or the handle is attached to the blade at or in the vicinity of one or more of these nodes, therefore, is relatively isolated from induced vibrations.

Abstract: The present invention relates to a guide tube for an ion beam in an ion implanter located adjacent a semiconductor wafer. Such guide tubes are provided to confine charged particles used for wafer neutralisation during implantation. According to the invention, a guide tube comprises an axis, open ends to receive an ion beam along said axis, a tube wall substantially parallel with said axis, and at least one opening through the tube wall forming a gas conduction passage from inside to outside the guide tube, said passage having a length aligned at an acute angle to said guide tube axis and a minimum dimension transverse to said length such that a line of sight through the passage perpendicular to said guide tube axis is substantially occluded.

Abstract: In a riding concrete finishing trowel, a stabilizer is operatively disposed between the frame and either the gearbox or a structure that is coupled to the gearbox. Such a stabilizer has been found to reduce the effects of rotor assembly vibration on the trowel greater than would be expected and even to improve steering response. In one embodiment, the stabilizer takes the form of a gas spring located between the frame and the pitch control post. Preferably, this gas spring is located relatively close to the top of the pitch control post so as to take advantage of the mechanical advantage offered by the spacing between that location and the gearbox.

Abstract: A portable vibratory screed includes a blade that is connected to a handle constructed to be manipulated by an operator. Nodes of minimum vibrational amplitude are formed at specific locations along the length of the blade when the exciter is driven at a rated operating speed. A site level and/or the handle is attached to the blade at or in the vicinity of one or more of these nodes, therefore, is relatively isolated from induced vibrations.

Abstract: A method is provided of making and using a walk behind rotary trowel that is “dynamically balanced” so as to minimize the forces/torque that the operator must endure to control and guide the trowel. Characteristics that are accounted for by this method include, but are not limited to, friction, engine torque, machine center of gravity, and guide handle position. As a result, dynamic balancing and consequent force/torque reduction were found to result when the machine's center of gravity was shifted substantially relative to a typical machine's center of gravity. Dynamic balancing can be achieved most practically by reversing the orientation of the engine relative to the guide handle assembly when compared to traditional walk behind rotary trowels and shifting the engine as far as practical to the right. This shifting has been found to reduce the operational forces and torque the operator must endure by at least 50% when compared to traditional machines.

Abstract: A walk behind rotary trowel is configured to be “dynamically balanced” so as to minimize the forces/torque that the operator must endure to control and guide the trowel. Characteristics that are accounted for by this design include, but are not limited to, friction, engine torque, machine center of gravity, and guide handle position. As a result, dynamic balancing and consequent force/torque reduction were found to result when the machine's center of gravity was shifted substantially relative to a typical machine's center of gravity. Dynamic balancing can be achieved most practically by reversing the orientation of the engine relative to the guide handle assembly when compared to traditional walk behind rotary trowels and shifting the engine as far as practical to the right. This shifting has been found to reduce the operational forces and torque the operator must endure by at least 50% when compared to traditional machines.

Abstract: A spotlight assembly is disclosed, including a spotlight energizeable to transmit a beam of light and having a lens frame configured to support a lens, and a cylinder coupled to the lens frame and adapted to receive at least one light guide through an opening in a sidewall of the cylinder.