Abstract: The hood for an air recirculation type of street sweeper forms a single, unidirectional air flow duct from the air inlet line to the air return. The top wall of the hood is formed to provide an air stream deflector that slants downwardly in the direction of the air return line and accelerates the air stream to insure that all debris is entrained in the air stream as it leaves the hood.

Abstract: A mobile street sweeper of the air recirculation pickup hood type has a hopper and a dust filter chamber. A main blower exhausts air from the hopper and introduces it into one end of the hood and air is returned to the hopper from the other end of the hood. An auxiliary blower withdraws air from the filter chamber and exhausts it to atmosphere. The hood is provided with an unobstructed front window and angled deflectors which windrow large objects into the window. The upstream end of the window is disposed at a zone wherein the static pressure of the air stream circulating along the hood is at atmospheric pressure and the downstream end of the window is disposed at a zone wherein the static pressure is only slightly less than atmospheric pressure.

Abstract: A hydraulic impact tool providing improved force absorption for facilitated manipulation by an operator. In the illustrated embodiment, the tool comprises a tamper which provides substantial tamping force with minimum vibration and uncontrolled bounce. The tool utilizes a hydraulic power system for improved noise reduction and minimizaton of fatigue. The tool provides a forward stroke wherein the force is applied for a preselected time, and a retraction stroke wherein the moving elements are retracted to a preselected position. The tool is adapted for use with a wide range of load resistances.

Abstract: A fitting for use with metal tubes adapted for critical applications such as involving high pressure and/or elevated temperatures for heavy external loads. The fitting includes a sleeve which is sealingly welded to the tube end and defines an improved cooperative nut and sleeve structure whereby the nut may be threadedly withdrawn from the body notwithstanding the projection of the sealing weld sufficiently from the tube to prevent complete withdrawal of the nut from the sleeve.