| 摘要 |
362,426. Hand-trucks. BARRETTCRAVENS CO., 1328, West Monroe Street, Chicago, U.S.A. Aug. 1, 1930, No. 23231. Convention date, Feb. 26. [Class 108 (i).] In a hand-truck comprising a main and a lifting frame the latter is raised by a lifting handle, a lifting lever and a link, the upper end of the link being moved vertically in line with the steering axis while the lower end is connected to lifting arms or cranks pivoted to the main frame. The elevating platform is adapted to be raised by repeated strokes of the steering handle 40 and is mounted on the main platform by pairs of links the rear ones 54 of which are connected by a bar 55 adapted to bear in the angle of a transverse angle bar 52. A shaft 61 journalled in the main frame 3 is provided with a ratchet 70 engageable by a pawl 75 carried by levers 71 which are oscillated by a link gear 80 from a shackle 85 adapted to be latched to the handle 40. The shaft 61 is provided with cranks 63 which raise the platform 50 by means of links 65. Retaining means for the platform 50 comprise a cylinder 93, Fig. 2, pivoted at 91 to a projection on the shaft 61. The cylinder 93 is connected to an oil chamber 94 and provided with' a plunger 98 a screwed portion, of which passes through a fixed nut 102. Valve and flap 101, 100 are provided at the end of the plunger 98 to check the return of the shaft towards the left as shown in Fig. 2. The other end of the plunger 98 is provided with a head 107 which permits, in a bearing, rotation and oscillation and a ratchet 120 with which engages a check pawl 130 preventing the backward rotation and consequent return of the plunger 98 to hold the platform 50 in its elevated position when the elevating ratchet is disengaged from its lifting pawl. Release of the lifting and check pawls 75, 130 to allow the platform 50 to descend is obtained from the operation of a pedal 144 through links 155, 170. |
