Patent ID: 7335138

Claim:
A hopper apparatus comprising: a treadle; a handrail formed of a vertical pole and a handlebar, said vertical pole having an end affixed to said treadle, and handlebar extending transverse to said vertical pole; and a spring component affixed to an underside of said treadle and having a surface suitable for contacting an underlying surface, said spring component comprising: an upper arc board; a lower arc board separate of said upper arc board; a fixing component having a first concave groove at one end affixed to a first end of said upper arc board and a first end of said lower arc board, said fixing component having a second concave groove at an opposite end affixed to a second end of said upper arc board and to a second end of said lower arc board, said fixing component comprising a rectangular spring frame with side members extending in parallel relation between said first and second concave grooves, said side members having a respective tongues aligned with each other and extending toward each other across an open interior space between said side members; and a spring block having a slot formed therein, said slot slidably receiving said tongues therein, said spring block having a first conical member extending upwardly therefrom so as to have a top end continuously bearing against an inner surface of said upper arc board, said spring block having a second conical member extending downwardly therefrom so as to have a bottom end continuously bearing against an inner surface of said lower arc board.