Chain trencher with shock-resistant silent drive

Claim 2

A trencher for attachment to an extension of the frame of a light truck having a plurality of cutters mounted on an endless chain for a continuous excavation of earth comprising: a. an extendable boom having a head end and a tail end slidable on the head end, and a lower side and an upper side, said boom pivotally mounted at said head end to the extension of the frame of the truck, b. a main drive sprocket having an axis rotatably mounted to the head end of the boom and engaging the endless chain, c. a tail sprocket rotating in the Same plane as the main drive sprocket and having an axis rotatably mounted to the tail end of the boom and engaging the endless chain, d. an auger drive sprocket rotating in the same plane as the main drive sprocket and having an axis rotatably mounted to the lower side of the boom means intermediate of the main drive sprocket and the tail sprocket and engaging the endless chain, said sprocket rotating in the same direction as the main and tail sprockets, e. chain guide rails mounted on the head end of the boom between the tail and the main and auger drive sprockets having upper and lower chain running surfaces lying in the plane of and between the sprockets and spaced slightly greater than half the base diameters of the sprockets from the centers thereof, f. a spring means mounted between the head end and the tail end of the slidably extendable boom urging the tail end from the head end along a line connecting the centers of the axes of the drive sprocket and the tail sprocket, and g. a hydraulic drive means for driving the main drive sprocket.

Claim 3

A trencher attachment as set forth in claim 1 wherein the chain guide rail running surface comprises wooden bearing plates mounted along each of said upper and lower sides of the boom.

Claim 4

A trencher for attachment to a frame of an engine driven tractor having auxiliary oil-hydraulic power comprising a boom having a lower and upper side and a head end and a tail end slidably mounted thereto, a tail sprocket journaled in said tail end, a pivot having a bored axis incorporated in the head end, a main drive sprocket in a common plane of rotation with the tail sprocket having a drive shaft journaled in the head end adjacent to the pivot, an auger drive sprocket in the common plane of rotation of the head and tail sprockets having a shaft journaled in the boom intermediate between the tail sprocket and the main drive sprocket and offset to the lower side of the boom, an endless chain engaging the tail sprocket, the main drive sprocket and the auger drive sprocket for rotation all in the same direction, extended side bars secured to both sides of the chain, a plurality of cutters bolted to every other of the extended side bars and alternately spaced on each side of said chain, a worm gear drive mounted on the head end of the boom connecting with an extension of the main drive sprocket shaft, a hydraulic motor operationally connected to the worm gear drive, a guide rail mounted to the lower side of the head end of the boom including laterally spaced steel side plates bolted to the sides thereof, said side plates straddling the common plane of rotation of the sprockets and running longitudinally between the tail sprocket and the auger drive sprocket providing guiding clearance for the moving of the chain therethrough, a wooden bearing plate mounted to and between the spaced side plates of the lower side of the head end of the boom extending longitudinally between the tail sprocket and the auger drive sprocket having upper and lower chain running surfaces lying In the plane of and between the sprockets and spaced slightly greater than half the base diameters of the sprockets from the centers thereof, a guide rail mounted to the upper side of the head end of the boom including laterally spaced steel side plates bolted to the sides thereof, said side plates straddling the common plane of rotation of the sprockets and running longitudinally between the tail sprocket and the main drive sprocket providing guiding clearance for the moving of the chains therethrough, a wooden bearing plate mounted to and between the spaced sideplates on the upper side of the head end of the boom extending longitudinally between the tail sprocket and the main drive sprocket having upper and lower chain running surfaces lying in the plane of and between the sprockets and spaced slightly greater than half the base diameters of the sprockets from the centers thereof, a slide bushing having its bore axis on a line joining the cenTers and in the common plane of rotation of the tail and main drive sprockets mounted on the head end of the boom, a tail shaft mounted on the tail end of the boom slidably mounted in the slide bushing, a pilot ring concentrically mounted on and pinned to said tail shaft along the length thereof at some distance from said bushing, a pilot ring guide cylinder having its bore axis on a line joining the centers and lying in the common plane of rotation of the tail and drive sprockets mounted in the head end of the boom extending from adjacent to the tail end to adjacent to the auger drive sprocket, a base end of the guide cylinder terminating said guide cylinder adjacent to the auger drive sprocket, a compression spring concentrically mounted on the tail shaft between the pilot ring and the base end of the guide cylinder urging the tail sprocket from the drive sprocket, a clevis having a bored axis parallel to and sidewise displaced from the bored axis of the pivot in the head end of the boom and mounted on the head end thereof on the side of the boom opposite to the worm gear drive in relation to the common plane of rotation of the sprockets, a first hydraulic jack having its rod end pivotally mounted in the clevis, a trencher support trunion member pivotally mounted to the cylinder end of said first hydraulic jack, a primary extension member pivotally mounted to the frame of the tractor and fixedly supporting the trencher support trunion member, a second hydraulic jack having its rod end pivotally mounted in the primary extension member and its cylinder end pivotally mounted in the frame of the tractor, a backfill blade mounted to the front end of the primary extension member, a first four-way spool valve in fluid communication with the hydraulic motor, a first engine driven hydraulic pump having a hydraulic fluid reservoir in fluid communication with the first spool valve, a second four-way spool valve in fluid communication with the second hydraulic jack, a second engine-driven hydraulic pump having the hydraulic fluid reservoir in fluid communication with the second spool valve, a third four-way spool valve in fluid communication with the first hydraulic jack and the second pump for the hydraulic supply thereto.

Claim 5

A trencher for attachment to a frame of an engine driven tractor having auxiliary oil-hydraulic power comprising a boom having a lower and upper side and a head end and a tail end slidably mounted thereto, a tail sprocket journaled in said tail end, a pivot having a bored axis incorporated in the head end, a main drive sprocket in a common plane of rotation with the tail sprocket having a drive shaft journaled in the head end adjacent to the pivot, an auger drive sprocket in the common plane of rotation of the head and tail sprockets having a shaft journaled in the boom intermediate between the tail sprocket and the main drive sprocket and offset to the lower side of the boom, an endless chain engaging the tail sprocket, the main drive sprocket and the auger drive sprocket for rotation all in the same direction, extended side bars secured to both sides of the chain, a plurality of cutters bolted to every other of the extended side bars and alternately spaced on each side of said chain, a worm gear drive mounted on the head end of the boom connecting with an extension of the main drive sprocket shaft, a hydraulic motor operationally connected to the worm gear drive, a guide rail mounted to the lower side of the head end of the boom including laterally spaced steel side plates bolted to the sides thereof, said side plates straddling the common plane of rotation of the sprockets and running longitudinally between the tail sprocket and the auger drive sprocket providing guiding clearance for the moving of the chain therethrough, a wooden bearing plate mounted to and between the spaced side plates of the lower side of the head end of the boom extending longitudinally between the tail sprocket and the auger drive sprocket having upper and lower chain running surfaces lying In the plane of and between the sprockets and spaced slightly greater than half the base diameters of the sprockets from the centers thereof, a guide rail mounted to the upper side of the head end of the boom including laterally spaced steel side plates bolted to the sides thereof, said side plates straddling the common plane of rotation of the sprockets and running longitudinally between the tail sprocket and the main drive sprocket providing guiding clearance for the moving of the chains therethrough, a wooden bearing plate mounted to and between the spaced sideplates on the upper side of the head end of the boom extending longitudinally between the tail sprocket and the main drive sprocket having upper and lower chain running surfaces lying in the plane of and between the sprockets and spaced slightly greater than half the base diameters of the sprockets from the centers thereof, a slide bushing having its bore axis on a line joining the cenTers and in the common plane of rotation of the tail and main drive sprockets mounted on the head end of the boom, a tail shaft mounted on the tail end of the boom slidably mounted in the slide bushing, a pilot ring concentrically mounted on and pinned to said tail shaft along the length thereof at some distance from said bushing, a pilot ring guide cylinder having its bore axis on a line joining the centers and lying in the common plane of rotation of the tail and drive sprockets mounted in the head end of the boom extending from adjacent to the tail end to adjacent to the auger drive sprocket, a base end of the guide cylinder terminating said guide cylinder adjacent to the auger drive sprocket, a compression spring concentrically mounted on the tail shaft between the pilot ring and the base end of the guide cylinder urging the tail sprocket from the drive sprocket, a clevis having a bored axis parallel to and sidewise displaced from the bored axis of the pivot in the head end of the boom and mounted on the head end thereof on the side of the boom opposite to the worm gear drive in relation to the common plane of rotation of the sprockets, a first hydraulic jack having its rod end pivotally mounted in the clevis, a trencher support trunion member pivotally mounted to the cylinder end of said first hydraulic jack, a primary extension member pivotally mounted to the frame of the tractor and fixedly supporting the trencher support trunion member, a second hydraulic jack having its rod end pivotally mounted in the primary extension member and its cylinder end pivotally mounted in the frame of the tractor, a backfill blade mounted to the front end of the primary extension member, a first four-way spool valve in fluid communication with the hydraulic motor, a first engine driven hydraulic pump having a hydraulic fluid reservoir in fluid communication with the first spool valve, a second four-way spool valve in fluid communication with the second hydraulic jack, a second engine-driven hydraulic pump having the hydraulic fluid reservoir in fluid communication with the second spool valve, a third four-way spool valve in fluid communication with the first hydraulic jack and the second pump for the hydraulic supply thereto.