Abstract: An operator for controlling the movement of a window sash relative to a frame with a raised surface along a frame sill thereof, wherein the operator includes a base having a first support surface, an aperture and a bottom exterior surface with a slot therein, the base attached to the frame with the raised surface fitting substantially within the slot. Also a method for manufacturing the operator includes the steps of passing the worm shaft through the hole with the worm shoulder engaging the internal shoulder and the worm disposed against the first support surface, fitting the arm to the central post, the arm in drivable engagement with the worm, placing the base and the cover together with the worm disposed between the first and second support surfaces and the central post.

Abstract: An operator for controlling the movement of a window sash relative to a frame with a raised surface along a frame sill thereof, wherein the operator includes a base having a first support surface, an aperture and a bottom exterior surface with a slot therein, the base attached to the frame with the raised surface fitting substantially within the slot. The operator also includes a cover secured to the base and having a second support surface with a hole therethrough defining an internal shoulder, the second support surface mating with the first support surface. A post extends from the cover and through the aperture in the base when the operator is assembled. An arm is pivotally secured to the post and attachable to the sash to control the movement of the sash between open and closed positions. A worm drivably engages the arm and has a worm shaft and a worm shoulder disposed on the worm shaft.

Abstract: An operator for controlling the movement of a window sash relative to a frame with a raised surface along a frame sill thereof, wherein the operator includes a base having a first support surface, an aperture and a bottom exterior surface with a slot therein, the base attached to the frame with the raised surface fitting substantially within the slot. The operator also includes a cover secured to the base and having a second support surface with a hole therethrough defining an internal shoulder, the second support surface mating with the first support surface. A post extends from the cover and through the aperture in the base when the operator is assembled. An arm is pivotally secured to the post and attachable to the sash to control the movement of the sash between open and closed positions. A worm drivably engages the arm and has a worm shaft and a worm shoulder disposed on the worm shaft.

Abstract: An operator for controlling the movement of a window sash relative to a frame with a raised surface along a frame sill thereof, wherein the operator includes a base having a first support surface, an aperture and a bottom exterior surface with a slot therein, the base attached to the frame with the raised surface fitting substantially within the slot. The operator also includes a cover secured to the base and having a second support surface with a hole therethrough defining an internal shoulder, the second support surface mating with the first support surface. A post extends from the cover and through the aperture in the base when the operator is assembled. An arm is pivotally secured to the post and attachable to the sash to control the movement of the sash between open and closed positions. A worm driveably engages the arm and has a worm shaft and a worm shoulder disposed on the worm shaft.

Abstract: A rivet for pivotally interconnecting first and second superposed links each having an opening therethrough, including a first head having a link engaging surface and an outer concave surface, and a shank having first and second portions with a shoulder therebetween, with the first portion being adjacent the head and receivable in the first link opening and the second portion being receivable in the second link opening. During assembly, the rivet is compressed so that the second portion is deformed to form a second head to secure the links between the first and second heads, and the first head is deformed to reduce the concavity of the recess therein and axially shift the first link over the first shank portion to virtually eliminate axial free play.