Abstract: A spacer grid includes interlocked straps comprising metal sheets or plates welded together to define a spacer grid having a top and bottom. The interlocked straps define a plurality of cells comprising vertical passages connecting the top and bottom of the spacer grid. The cells include: upper dimples proximate to the top of the spacer grid and distal from the mid-plane of the spacer grid; lower dimples proximate to the bottom of the spacer grid and distal from the mid-plane of the spacer grid; cantilevered upper springs having fuel rod engagement surfaces proximate to the top of the spacer grid and distal from the mid-plane of the spacer grid; and cantilevered lower springs having fuel rod engagement surfaces proximate to the bottom of the spacer grid and distal from the mid-plane of the spacer grid.

Abstract: A spacer grid includes intersecting straps defining cells with springs and dimples arranged to hold fuel rods passing through the cells. The springs are dual cantilevered springs with a bridge section between the distal end of the spring and the base. The distal portion of the spring is less stiff than the bridge section. The bridge section creates a bump which acts as a stop or travel limiter to prevent loss of grip force due to excessive spring deflection.

Abstract: A spacer grid includes interlocked straps comprising metal sheets or plates welded together to define a spacer grid having a top and bottom. The interlocked straps define a plurality of cells comprising vertical passages connecting the top and bottom of the spacer grid. The cells include: upper dimples proximate to the top of the spacer grid and distal from the mid-plane of the spacer grid; lower dimples proximate to the bottom of the spacer grid and distal from the mid-plane of the spacer grid; cantilevered upper springs having fuel rod engagement surfaces proximate to the top of the spacer grid and distal from the mid-plane of the spacer grid; and cantilevered lower springs having fuel rod engagement surfaces proximate to the bottom of the spacer grid and distal from the mid-plane of the spacer grid.

Abstract: A spacer grid includes interlocked straps comprising metal sheets or plates welded together to define a spacer grid having a top and bottom. The interlocked straps define a plurality of cells comprising vertical passages connecting the top and bottom of the spacer grid. The cells include: upper dimples proximate to the top of the spacer grid and distal from the mid-plane of the spacer grid; lower dimples proximate to the bottom of the spacer grid and distal from the mid-plane of the spacer grid; cantilevered upper springs having fuel rod engagement surfaces proximate to the top of the spacer grid and distal from the mid-plane of the spacer grid; and cantilevered lower springs having fuel rod engagement surfaces proximate to the bottom of the spacer grid and distal from the mid-plane of the spacer grid.

Abstract: A spacer grid includes intersecting straps defining cells with springs and dimples arranged to hold fuel rods passing through the cells. The direction of the springs switches at a switch point in the spacer grid that is not at the center of the spacer grid. The intersecting straps may include a first set of mutually parallel straps including a first transition strap and a second set of mutually parallel straps including a second transition strap, with the second set intersecting the first set. The springs of the first set of mutually parallel straps face away from the first transition strap, and the springs of the second set of mutually parallel straps face away from the second transition strap. The outer straps in some embodiments include dimples but not springs.

Abstract: A spacer grid includes intersecting straps defining cells with springs and dimples arranged to hold fuel rods passing through the cells. The springs are dual cantilevered springs with a bridge section between the distal end of the spring and the base. The distal portion of the spring is less stiff than the bridge section. The bridge section creates a bump which acts as a stop or travel limiter to prevent loss of grip force due to excessive spring deflection.

Abstract: A spacer grid includes intersecting straps defining cells with springs and dimples arranged to hold fuel rods passing through the cells. The direction of the springs switches at a switch point in the spacer grid that is not at the center of the spacer grid. The intersecting straps may include a first set of mutually parallel straps including a first transition strap and a second set of mutually parallel straps including a second transition strap, with the second set intersecting the first set. The springs of the first set of mutually parallel straps face away from the first transition strap, and the springs of the second set of mutually parallel straps face away from the second transition strap. The outer straps in some embodiments include dimples but not springs.

Abstract: A spacer grid includes interlocked straps comprising metal sheets or plates welded together to define a spacer grid having a top and bottom. The interlocked straps define a plurality of cells comprising vertical passages connecting the top and bottom of the spacer grid. The cells include: upper dimples proximate to the top of the spacer grid and distal from the mid-plane of the spacer grid; lower dimples proximate to the bottom of the spacer grid and distal from the mid-plane of the spacer grid; cantilevered upper springs having fuel rod engagement surfaces proximate to the top of the spacer grid and distal from the mid-plane of the spacer grid; and cantilevered lower springs having fuel rod engagement surfaces proximate to the bottom of the spacer grid and distal from the mid-plane of the spacer grid.

Abstract: A tracer is provided for tracing a lens mount of an eyeglass frame, a lens or a lens pattern. The tracer comprises an object engager and an actuator. The object engager is adapted to engage the lens mount, the lens or the lens pattern. The actuator is adapted to move the object engager into contact with and then along the lens mount, the lens or the lens pattern in such a way that during movement therealong, the object engager remains against the object being traced even when the shape thereof includes high wrap. Preferably, the tracer has a shift mechanism adapted to shift the object engager from alignment with the lens mount to alignment with a second lens mount of the eyeglass frame. The actuator preferably is further adapted to trace the second lens mount in substantially the same way as the first. The actuator further includes a rotator and a pivot mechanism. The rotator is adapted to rotate the object engager along the object being traced.

Abstract: A tracer is provided for tracing a lens mount of an eyeglass frame, a lens or a lens pattern. The tracer comprises an object engager and an actuator. The object engager is adapted to engage the lens mount, the lens or the lens pattern. The actuator is adapted to move the object engager into contact with and then along the lens mount, the lens or the lens pattern in such a way that during movement therealong, the object engager remains against the object being traced even when the shape thereof includes high wrap. Preferably, the tracer has a shift mechanism adapted to shift the object engager from alignment with the lens mount to alignment with a second lens mount of the eyeglass frame. The actuator preferably is further adapted to trace the second lens mount in substantially the same way as the first. The actuator further includes a rotator and a pivot mechanism. The rotator is adapted to rotate the object engager along the object being traced.

Abstract: A tracer is provided for tracing a lens mount of an eyeglass frame, a lens or a lens pattern. The tracer comprises an object engager and an actuator. The object engager is adapted to engage the lens mount, the lens or the lens pattern. The actuator is adapted to move the object engager into contact with and then along the lens mount, the lens or the lens pattern in such a way that during movement therealong, the object engager remains against the object being traced even when the shape thereof includes high wrap. Preferably, the tracer has a shift mechanism adapted to shift the object engager from alignment with the lens mount to alignment with a second lens mount of the eyeglass frame. The actuator preferably is further adapted to trace the second lens mount in substantially the same way as the first. The actuator further includes a rotator and a pivot mechanism. The rotator is adapted to rotate the object engager along the object being traced.