GB119306A - Improved Construction of Elevating Truck, Transporter or the like. - Google Patents

Abstract

119,306. Collis, A. Oct. 17, 1917. Hand-trucks with lifting platforms adapted to be run under the load. The lifting, means comprises ratchet and pawl jack mechanism actuated by the truck or a separate handle to raise and lower the platform step by step. The truck shown has the platform 6 mounted upon four pillars 7 each working in a frame 4 bolted to the under frame 1 and having ratchet teeth 8 engaged by a pawl 13 on one arm 12 of a bell-crank lever pivoted at 10. The other arm 9 of this lever is connected to a rod 25 which has a forward extension 31 for engagement with a jaw 28 on the truck handle 27 mounted on the steering axle 32. A retaining pawl 11 also is mounted on the pivot 10. To raise the platform, the handle is swung to and fro. During the rearward movement, it pushes the bars 25, thereby raising the platform the space of a tooth of the ratchet by the pawl 13. A spring 30 returns the bars 25 and pawl 13 during the forward movement of the handle. For effecting the lowering of the platform there is provided a member 14 freely mounted on the pivot 10 and having cam surfaces 33<a>, 33<b> engaged by a spring-pin 15. When the platform reaches the uppermost position, a projection 21 on a rod 19 fixed to the platform engages a pin 22 on the member 14 and swings this member from the position shown in Fig. 3 to that shown in Fig. 5 so that, urged by the spring-pin 15 against a pin 23 on the pawl 11, it then tends to disengage this pawl from the ratchet. In the forward position of the truck handle however, a. pin 24 on the pawl 13 drops into a recess 17 in and depresses the member 14, disengaging this pawl and permitting the engagement of the pawl 11. By swing- ing the handle rearwardly, the pawl 13 is engaged with the ratchet and the platform can be slightly raised to allow the member 14 to disengage the pawl 11. The platform can then be lowered the space of a tooth, when the pawl 11 again becomes engaged and the pawl 13 is disengaged as shown in Fig. 5. At the completion of the lowering movement, a second projection on the rod 19 returns the member 14 to the position shown in Fig 3,