Abstract: A manhole system including a cover, a frame receiving the cover and at least one security device securing the cover to the frame.

Abstract: A passive self-determined position fixing system for use by aircraft and other users such as sea-going vessels utilizes a directional radar in combination with an omnidirectional radar facility to produce a directional radar beam and simultaneous omnidirectional radar transmission. A television type broadcast facility provides a broadcast of the PPI display of the directional radar system. The directional radar pulse signals together with the omnidirectionally retransmitted radar pulse signals are processed by the position fixing system aboard the host aircraft or the like to determine range information. A display system such as a conventional television receiver responds to the broadcast PPI display to produce a similar display within the host aircraft. The position fixing system combines the PPI type display together with the information with the directional and omnidirectional radar transmissions to identify the user or host aircraft or vessel upon the PPI type display.

Abstract: Safety supporting devices to automatically securely maintain the rearwardly tilted elevated condition of the cargo dumping box of overland drayage vehicles are provided. The safety supporting device comprises an elongated multi-teeth rack freely pivotably depending from the dump box rearward portion and automatically securely engageable with a detent rigidly mounted to the vehicle chassis. The rack and detent combination maintains the selected degree of dump box rearward tilt. When it is later desired to allow the dump box to descend, vehicular personnel actuatably withdraw the rack from the detent, including desirable optional provision for remotely controlled withdrawal initiatable from the drayman's station e.g. the operator's cab of a dump truck.

Abstract: Disclosed are apparatus including novel workman's tool for removing hides, select cuts of meat, and generally carving away from animal carcasses relative large portions in cleanly cutaway non-comminuted condition. The apparatus, manually wieldable workman's tool, is deftly employable in a manner analagous to a conventional honed butcherman's knife; however, the knife-like shank of the tool includes tiny orifices emitting compressed air jets of sufficiently high intensity to carve the animal carcass. The emitted air jets to effect carving are made relatively free of solid particles and excessive moisture thereby maintaining the integrity of the air jets and the cleanly cutaway noncomminuted condition of the removed carcass portions.

Abstract: Anti-jackknifing apparatus for combination with conventional tractor-drawn trailers wherein the tractor includes a forward operator's cab and a rearward fifth wheel assembly having a skid-plate. The skid-plate conventionally includes a pair of longitudinally rearwardly extending guide-lugs having outward-sides and also inward-sides horizontally angularly converging toward an upright kingpin or other pivotal association with the trailer. The anti-jackknifing apparatus comprises a generally horizontal longitudinally extending ram terminating as a forward head-end, which ram and head-end has an inactive normal-station and also an anti-jackknifing extended-station respectively located rearwardly remote from and toward the skid-plate.

Abstract: Anti-jackknifing apparatus for combination with conventional tractor-drawn trailers wherein the tractor includes a forwardly disposed operator's cab and a rearwardly disposed fifth wheel assembly having a skid-plate. The skid-plate conventionally includes a pair of longitudinally rearwardly extending guide-lugs having therebetween a V-slot horizontally converging toward an upright kingpin or other pivotal association with the trailer. The anti-jackknifing apparatus comprises a generally horizontal longitudinally extending restraining-tongue terminating as a forward head-part, which head-part has an inactive normal-station and also an anti-jackknifing extended-station respectively located remote from and abuttably within the skid-plate V-slot during a potentially jackknifing panic situation.