Power transmission mechanism for a tractor

Claim 2

A power transmission mechanism for a tractor, comprising: a front transmission casing; a rear transmission casing; means coupling said front transmission casing to said rear transmission casing to define a single transmission casing; means for receiving and supporting an upper rotatable input shaft near the top of said front casing; means, located generally below said coupling means, for receiving and supporting a lower rotatable input shaft in said front casing; a drive-speed changing unit comprising: (a) a speed change shaft, driven by said lower input shaft, located generally below and to the side of said lower input shaft; and (b) a pinion shaft, driven by said speed change shaft, located generally below and to the side of said speed change shaft; a pinion gear on the end of said pinion shaft that extends toward said rear casing; a differential gear unit supported within said rear casing, said differential gear unit comprising a ring gear driven by said pinion gear; a PTO clutch unit with a clutch shaft coupled to said upper input shaft; a clutch driven shaft extending from said PTO clutch unit; a rear PTO shaft located generally below said clutch unit and extending out of said rear casing; a fixed gear on said rear PTO shaft located at the end of said rear PTO shaft nearest said clutch unit; a mid PTO shaft located generally below said rear PTO shaft and beside said pinion shaft, and extending out of said front transmission casing; a fixed gear on said mid PTO shaft; and drive means coupling said clutch driven shaft to said mid PTO shaft, and to said rear PTO shaft.

Claim 3

A power transmission mechanism for a tractor, comprising: a front transmission casing; a rear transmission casing; means coupling said front transmission casing to said rear transmission casing to define a single transmission casing; means for receiving and supporting an upper rotatable input shaft near the top of said front casing; means, located generally below said coupling means, for receiving and supporting a lower rotatable input shaft in said front casing; a drive-speed changing unit comprising: (a) a speed change shaft, driven by said lower input shaft, located generally below and to the side of said lower input shaft; and (b) a pinion shaft, driven by said speed change shaft, located generally below and to the side of said speed change shaft; a pinion gear on the end of said pinion shaft that extends toward said rear casing; a differential gear unit supported within said rear casing, said differential gear unit comprising a ring gear driven by said pinion gear; a PTO clutch unit with a clutch shaft coupled to said upper input shaft; a clutch driven shaft extending from said PTO clutch unit; a rear PTO shaft located generally below said clutch unit and extending out of said rear casing; a fixed gear on said rear PTO shaft located at the end of said rear PTO shaft nearest said clutch unit; a mid PTO shaft located generally below said rear PTO shaft and beside said pinion shaft, and extending out of said front transmission casing; a fixed gear on said mid PTO shaft; a PTO changeover shaft located generally between said rear PTO shaft and said mid PTO shaft; means for driving said PTO changeover shaft with said clutch driven shaft; and driving means, on said PTO changeover shaft, for driving said mid PTO shaft and said rear PTO shaft, comprising: a first gear, coupled to said clutch driven shaft, a second gear, coupled to said mid PTO shaft, a third gear, coupled to said rear PTO shaft, and a changeover slider, having a first position for engaging said first gear with said second gear, and a second position for engaging said first gear with both said second and said third gears.

Claim 4

A power transmission mechanism for a tractor, comprising: a front transmission casing; a rear transmission casing; means coupling said front transmission casing to said rear transmission casing to define a single transmission casing; means for receiving and supporting an upper rotatable input shaft near the top of said front casing; means, located generally below said coupling means, for receiving and supporting a lower rotatable input shaft in said front casing; a drive-speed changing unit comprising: (a) a speed change shaft, driven by said lower input shaft, located generally below and to the side of said lower input shaft; and (b) a pinion shaft, driven by said speed change shaft, located generally below and to the side of said speed change shaft; a pinion gear on the end of said pinion shaft that extends toward said rear casing; a differential gear unit supported within said rear casing, said differential gear unit comprising a ring gear driven by said pinion gear; a PTO clutch unit with a clutch shaft coupled to said upper input shaft; a clutch driven shaft extending from said PTO clutch unit; a rear PTO shaft located generally below said clutch unit and extending out of said rear casing; a fixed gear on said rear PTO shaft located at the end of said rear PTO shaft nearest said clutch unit; a mid PTO shaft located generally below said rear PTO shaft and beside said pinion shaft, and extending out of said front transmission casing; a fixed gear on said mid PTO shaft; a PTO changeover shaft located generally between said rear PTO shaft and said mid PTO shaft; means for driving said PTO changeover shaft with said clutch driven shaft; and driving means, on said PTO changeover shaft, for driving said mid PTO shaft and said rear PTO shaft, comprising: a first gear, coupled to said clutch driven shaft, a second gear, coupled to said mid PTO shaft, a third gear, coupled to said rear PTO shaft, and a changeover slider, having a first position for engaging said first gear with said second gear, and a second position for engaging said first gear with both said second and said third gears.

Claim 5

The power transmission mechanism of claim 2, wherein said means for driving said PTO changeover shaft comprises: a countershaft with a fixed gear interposed generally between said clutch driven shaft and said PTO changeover shaft.

Claim 6

A power transmission mechanism for a tractor as set forth in claim 2, further comprising: a clutch housing enclosing said PTO clutch unit, and disposed close to said transmission casing; PTO brake plates interposed between the outer surface of said clutch housing and said transmission casing; PTO clutch plates interposed between the inner surface of said clutch housing and said clutch shaft; a PTO clutch urging lever extending across said PTO brake plates and said PTO clutch plates, and coupled to said clutch housing such that said lever pivots between a first position of engagement, with said brake plates, and a second position of engagement, with said clutch plates; and a PTO clutch slider that slides axially to contact and pivot said PTO clutch urging lever, thereby providing that PTO braking action occurs simultaneously with disengagement of said PTO clutch.

Claim 7

A power transmission mechanism for a tractor as set forth in claim 4, further comprising: means biasing said clutch urging lever normally toward said first position.

Claim 8

A power transmission mechanism for a tractor, comprising: a front transmission casing; a rear transmission casing; means coupling said front transmission casing to said rear transmission casing to define a single transmission casing; means for receiving and supporting an upper rotatable input shaft near the top of said front casing; means, located generally below said coupling means, for receiving and supporting a lower rotatable input shaft in said front casing; a drive-speed changing unit comprising: (a) a speed change shaft, driven by said lower input shaft, located generally below and to the side of said lower input shaft; and (b) a pinion shaft, driven by said speed change shaft, located generally below and to the side of said speed change shaft; a pinion gear on the end of said pinion shaft that extends toward said rear casing; a front vertical wall; a rear vertical wall; longitudinal vertical walls connecting said front vertical wall and said rear vertical wall; an axle housing; a differential gear unit supported within said rear transmission casing by said longitudinal wall and said axle housing, said differential gear unit comprising a ring gear driven by said pinion gear; a PTO clutch unit with a clutch shaft coupled to said upper input shaft; a clutch driven shaft extending from said PTO clutch unit; a rear PTO shaft located generally below said clutch unit and extending out of said rear casing; a fixed gear on said rear PTO shaft located at the end of said rear PTO shaft nearest said clutch unit; a mid PTO shaft located generally below said rear PTO shaft and beside said pinion shaft, and extending out of said front transmission casing; a fixed gear on said mid PTO shaft; and drive means coupling said clutch driven shaft to said mid PTO shaft, and to said rear PTO shaft.

Claim 9

A power transmission mechanism for a tractor, comprising: a front transmission casing; a rear transmission casing; means coupling said front transmission casing to said rear transmission casing to define a single transmission casing; means for receiving and supporting an upper rotatable input shaft near the top of said front casing; means, located generally below said coupling means, for receiving and supporting a lower rotatable input shaft in said front casing; a drive-speed changing unit comprising: (a) a speed change shaft, driven by said lower input shaft, located generally below and to the side of said lower input shaft; and (b) a pinion shaft, driven by said speed change shaft, located generally below and to the side of said speed change shaft; a pinion gear on the end of said pinion shaft that extends toward said rear casing; a front vertical wall; a rear vertical wall; longitudinal vertical walls connecting said front vertical wall and said rear vertical wall; an axle housing; a differential gear unit supported within said rear transmission casing by said longitudinal wall and said axle housing, said differential gear unit comprising a ring gear driven by said pinion gear; a PTO clutch unit with a clutch shaft coupled to said upper input shaft; a clutch driven shaft extending from said PTO clutch unit; a rear PTO shaft located generally below said clutch unit and extending out of said rear casing; a fixed gear on said rear PTO shaft located at the end of said rear PTO shaft nearest said clutch unit; a mid PTO shaft located generally below said rear PTO shaft and beside said pinion shaft, and extending out of said front transmission casing; a fixed gear on said mid PTO shaft; and drive means coupling said clutch driven shaft to said mid PTO shaft, and to said rear PTO shaft.