Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
277 words
A power-driven wheelchair, comprising: a main frame including parallel cross members connecting horizontally aligned side members having forward ends and terminating rearwardly in parallel transversely aligned angularly upward and rearwardly directed end portions; a chair frame pivotally supported by said main frame for pivoting movement about a horizontal axis toward and away from the rearward end portion of said main frame; a pair of stud axles journalled by said main frame intermediate its ends and respectively projecting, at one end portion, laterally of said frame side members; a sub frame underlying the forward end portions of said main frame side members and being pivotally connected with said main frame for vertical pivoting movement of said sub frame about a horizontal axis intermediate the length of said main frame; two pairs of endless traction belt means supported respectively by said main frame and said sub frame and driven by the respective laterally projecting end portion of said stub axles; a pair of ground-engaging wheels connected, respectively, with the forward end portions of said sub frame; a pivoting frame connected with said main frame rearwardly of said stub axles for vertical pivoting movement about a horizontal axis; a caster wheel connected with said pivoting frame rearwardly of its connection with said main frame for normally horizontally supporting said endless traction belt means, in combination with said ground-engaging wheels, in a plane spaced above said ground; chair frame retractor means connected with said chair frame and said pivoting frame, respectively, for lowering said chair frame toward said main frame while raising said pivoting frame and vice versa; and, selectively operable power means connected in driving relation with said stub axles.
Claim 2
Dependent Claim
277 words
A power-driven wheelchair, comprising: a main frame including parallel cross members connecting horizontally aligned side members having forward ends and terminating rearwardly in parallel transversely aligned angularly upward and rearwardly directed end portions; a chair frame pivotally supported by said main frame for pivoting movement about a horizontal axis toward and away from the rearward end portion of said main frame; a pair of stud axles journalled by said main frame intermediate its ends and respectively projecting, at one end portion, laterally of said frame side members; a sub frame underlying the forward end portions of said main frame side members and being pivotally connected with said main frame for vertical pivoting movement of said sub frame about a horizontal axis intermediate the length of said main frame; two pairs of endless traction belt means supported respectively by said main frame and said sub frame and driven by the respective laterally projecting end portion of said stub axles; a pair of ground-engaging wheels connected, respectively, with the forward end portions of said sub frame; a pivoting frame connected with said main frame rearwardly of said stub axles for vertical pivoting movement about a horizontal axis; a caster wheel connected with said pivoting frame rearwardly of its connection with said main frame for normally horizontally supporting said endless traction belt means, in combination with said ground-engaging wheels, in a plane spaced above said ground; chair frame retractor means connected with said chair frame and said pivoting frame, respectively, for lowering said chair frame toward said main frame while raising said pivoting frame and vice versa; and, selectively operable power means connected in driving relation with said stub axles.
Claim 3
Dependent Claim
70 words
The wheelchair according to claim 1 in which said chair frame retractor means includes: a reversible motor connected with said chair frame, said motor having a drive shaft; an internally threaded cylinder pivotally connected At one end with said pivoting frame and projecting at its other end portion toward said motor; and, a screw shaft coaxially connected with said motor drive shaft and threadedly received by said internally threaded cylinder.
Claim 4
Dependent Claim
109 words
The wheelchair according to claim 2 and further including: a rotatable shaft extending transversely through said main frame for connecting said pivoting frame to said main frame; a chair frame support plate connected with said rotatable shaft at the respective opposing sides of said pivoting frame; a latch mounted on one said chair frame support plate and releaseably supporting said pivoting frame; a cam connected with said rotatable shaft and having a cam surface bearing against said latch; and, a handle connected with one end of said rotatable shaft for releasing said latch and permitting said pivoting frame to fall by gravity toward a caster wheel contacting horizontal surface.
Claim 5
Dependent Claim
43 words
The wheelchair according to claim 3 and further including: first shock absorbing means connected with said main frame and said pivoting frame for cushioning downward movement of the rearward end portion of said pivoting frame and said main frame toward a horizontal surface.
Claim 6
Dependent Claim
53 words
The wheelchair according to claim 4 and further including: second shock absorbing means extending between said main frame and said sub frame for cushioning movement of the forward end portion of said main frame toward said sub frame when said wheelchair is moved from a horizontal supporting plane to a downwardly inclined plane.