US3791456A — Tractor hitch system including a vertically swing…

Claim 1

Independent Claim 315 words

In a tractor of the type including a chassis, a pair of laterally spaced draft links, a pair of universal pivot connections respectively joining forward end portions of said pair of draft links to said chassis and defining a horizontal pivot axis about which the draft links are vertically swingable between an upper transport position and a lower working position, selectively actuatable power lift means connected between the chassis and said pair of draft links for swinging the latter between said transport and working positions, a drawbar located centrally between said pair of draft links and having a forward end portion positioned beneath said chassis, connection means securing the forward end portion of said drawbar to said chassis and defining a horizontal pivot axis about which said drawbar is swingable vertically between a raised generally horizontal towing position and a lowered pickup position and said pair of draft links being normally fixedly spaced laterally from each other when connected to an implement, the improvement comprising: unitary sway-limiting and motion transfer means being connected between said pair of draft links and said drawbar for raising and lowering said drawbar, respectively, in response to said draft links being raised and lowered by actuation of said power lift means, and for preventing said pair of draft links from swaying when they are in said transport position and are held fixed in said normal laterally spaced relationship to each other; and connection means located on said chassis and said sway-limiting and motion transfer means being optionally attachable to said connection means instead of to said drawbar assembly and said sway-limiting and motion transfer means and connection means together forming linkage means for preventing the draft links from swaying in any position of the draft links between and including said upper transport and lower working positions when the latter are fixed in said normal, laterally spaced relationship to each other.

Claim 2

Dependent Claim 315 words

In a tractor of the type including a chassis, a pair of laterally spaced draft links, a pair of universal pivot connections respectively joining forward end portions of said pair of draft links to said chassis and defining a horizontal pivot axis about which the draft links are vertically swingable between an upper transport position and a lower working position, selectively actuatable power lift means connected between the chassis and said pair of draft links for swinging the latter between said transport and working positions, a drawbar located centrally between said pair of draft links and having a forward end portion positioned beneath said chassis, connection means securing the forward end portion of said drawbar to said chassis and defining a horizontal pivot axis about which said drawbar is swingable vertically between a raised generally horizontal towing position and a lowered pickup position and said pair of draft links being normally fixedly spaced laterally from each other when connected to an implement, the improvement comprising: unitary sway-limiting and motion transfer means being connected between said pair of draft links and said drawbar for raising and lowering said drawbar, respectively, in response to said draft links being raised and lowered by actuation of said power lift means, and for preventing said pair of draft links from swaying when they are in said transport position and are held fixed in said normal laterally spaced relationship to each other; and connection means located on said chassis and said sway-limiting and motion transfer means being optionally attachable to said connection means instead of to said drawbar assembly and said sway-limiting and motion transfer means and connection means together forming linkage means for preventing the draft links from swaying in any position of the draft links between and including said upper transport and lower working positions when the latter are fixed in said normal, laterally spaced relationship to each other.

Claim 3

Dependent Claim 44 words

The invention defined in claim 1 wherein said sway-limiting and motion transfer means includes a pair of lengths of chain, each chain having one end connected to a respective one of said draft links and having the other end connected to said drawbar assembly.

Claim 4

Dependent Claim 27 words

The invention defined in claim 1 and further including releasable latch means for releasably fixing said drawbar assembly to said chassis in a generally horizontal transport position.

Claim 5

Dependent Claim 27 words

The invention defined in claim 2 and further including releasable latch means for releasably fixing said drawbar assembly to said chassis in said generally horizontal transport position.

Claim 6

Dependent Claim 119 words

The invention defined in claim 2 wherein a pair of pivot connections are located on said chassis at laterally spaced positions along said horizontal pivot axis of said draft links and the ends of the pair of chains that are connected to the drawbar assembly being respectively optionally connectible to said pair of pivot connections for movement coaxial with that of the draft links and the lengths of the chains being such that they are relatively taut when connected to said chassis, whereby when said chains are connected to said chassis said draft links are prevented from swaying in all positions of said draft links when the latter are fixed in said normal, laterally spaced relationship to each other.

Claim 7

Dependent Claim 205 words

The invention defined in claim 3 wherein said releasable latch means comprises a pair of laterally spaced overcenter linkage means including a pair of laterally spaced latch seats fixed to said chassis and including a pair of upwardly facing, concave seating surfaces respectively formed about a first pair of centers of curvature; a pair of laterally spaced links respectively pivotally connected to said drawbar assembly for vertical swinging movement; a pair of latch levers respectively pivotally connected to said pair of links and respectively including a pair of convex camming surfaces having radii of curvature substantially equal to that of said seating surfaces; the centers of curvature of said camming surfaces being displaced from the pivot connections of said levers with said links; and said levers and links being so located relative to said seating surfaces that when said drawbar assembly is in a horizontal transport position, said camming surfaces are engageable with said seating surfaces and said levers are movable to dispose the pivot connections between said levers and links between an unlatched position to one side of the centers of curvature of said seating surfaces, and an overcenter latched position to the other side of the center of curvature of said seating surfaces.

Claim 8

Dependent Claim 206 words

The inventIon defined in claim 4 wherein said releasable latch means comprises a pair of laterally spaced overcenter linkage means including a pair of laterally spaced latch seats fixed to said chassis and including a pair of upwardly facing, concave seating surfaces respectively formed about a first pair of centers of curvature; a pair of laterally spaced links respectively pivotally connected to said drawbar assembly for vertical swinging movement; a pair of latch levers respectively pivotally connected to said pair of links and respectively including a pair of convex camming surfaces having radii of curvature substantially equal to that of said seating surfaces; the centers of curvature of said camming surfaces being displaced from the pivot connections of said levers with said links; and said levers and links being so located relative to said seating surfaces that when said drawbar assembly is in a said horizontal transport position, said camming surfaces are engageable with said seating surfaces and said levers are movable to dispose the pivot connections between said levers and links between an unlatched position to one side of the centers of curvature of said seating surfaces, and an overcenter latched position to the other side of the center of curvature of said seating surfaces.

Claim 9

Dependent Claim 33 words

The invention defined in claim 6 wherein said latch seats comprise a pair of laterally extending vertical plates; said links respectively including pairs of spaced straps movable into straddling relationship to said plates.

Claim 10

Dependent Claim 33 words

The invention defined in claim 7 wherein said latch seats comprise a pair of laterally extending vertical plates; said links respectively including pairs of spaced straps movable into straddling relationship to said plates.

Claim 11

Dependent Claim 212 words

In a tractor of the type including a chassis, a pair of draft links and a drawbar assembly extending rearwardly from and pivotally connected to said chassis for vertical swinging movement, power lift means connected between said chassis and said draft links for raising and lowering the latter, a pair of sway chains respectively having one of their ends connected to said pair of draft links; a first attachment means located on said tractor along the axis of pivotal movement of said draft links and a second attachment means located on said tractor at a location displaced from said axis; the other of the ends of said sway chains being optionally connectible to said first and second attachment means, and the lengths of the chains being so related to said first and second attachment means that the draft links are respectively prevented from swaying in all positions thereof when the chains are attached to said first attachment means, and free to sway except when they are in a raised transport position when said chains are connected to said second attachment means, the improvement comprising: said second attachment means being located on said drawbar assembly and releasable latch means for securing said drawbar assembly to said chassis in a generally horizontal transport position.

Claim 12

Dependent Claim 212 words

In a tractor of the type including a chassis, a pair of draft links and a drawbar assembly extending rearwardly from and pivotally connected to said chassis for vertical swinging movement, power lift means connected between said chassis and said draft links for raising and lowering the latter, a pair of sway chains respectively having one of their ends connected to said pair of draft links; a first attachment means located on said tractor along the axis of pivotal movement of said draft links and a second attachment means located on said tractor at a location displaced from said axis; the other of the ends of said sway chains being optionally connectible to said first and second attachment means, and the lengths of the chains being so related to said first and second attachment means that the draft links are respectively prevented from swaying in all positions thereof when the chains are attached to said first attachment means, and free to sway except when they are in a raised transport position when said chains are connected to said second attachment means, the improvement comprising: said second attachment means being located on said drawbar assembly and releasable latch means for securing said drawbar assembly to said chassis in a generally horizontal transport position.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1977-02-11	1977-08-13	1978-02-12	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1981-02-11	1981-08-13	1982-02-12	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1985-02-11	1985-08-13	1986-02-12	$7700.00	Window Closed / Lapsed

Tractor hitch system including a vertically swingable drawbar powered by a draft link actuator

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