Abstract: An improved human-powered engine which is actuated by forward and rearward movement of the body to cause extension of a resilient member which serves to provide driving motion to a wheel, propeller or the like.

Abstract: A pocket flask to be carried within the user's pocket having a hollow housing provided with a curved side wall and a bottom wall connected to the sidewall. A first partition wall divides the housing into a first liquid chamber and a second chamber. A second partition wall divides the second chamber into a tobacco chamber and a pipe housing chamber. A pipe is telescopically receivable within the pipe housing chamber and a first cover, which is pivotally connected to the housing functions to move pipe inwardly of the pipe housing chamber against the urging of a spring. The first cover is movable between a first open position and a second closed position to gain access to the pipe and to the tobacco. A closure wall which has a pouring opening, is connected to the housing for substantially closing the first liquid chamber. A cap removably closes the pouring opening.

Abstract: an improved sliding door latch comprising a latch plate attached to the leading edge of the door and projecting outwardly on either side of the door to enable a person to grasp the latch plate to slide the door open or closed, and a latch arm pivotally secured to the door jamb and movable between a first unlocked position which permits the door to be opened or closed and a latched position engaging the latch plate and preventing movement of the door.

Abstract: An all-surface vehicle comprising a pair of large inflatable tubes mounted on a common axis with sufficient buoyancy to enable the vehicle to travel on water and having a motor for independently driving each of the tubes, together with a passenger or load carrying compartment; the motor and compartment being mounted with their center of gravity below the axis of the tubes.

Abstract: A geothermal drilling and recovery system comprising a drilling rig having an elevator with a laser and a radar gun mounted on said elevator, a drill pipe, a rotating mirror mounted adjacent the lower end of said drill pipe and means for establishing a vacuum adjacent said lower end of said drill pipe to remove and recover heat and drilling debris therefrom.

Abstract: Removable tap covers for dancing shoes which can quickly and easily be placed on the taps to prevent accumulation of dirt and grime in the taps, yet which can quickly and easily be removed to allow the full effect of the taps for dancing.