Patent GB-647817-A (GB)
Title: Improvements in or relating to elevating apparatus
Inventor: NEWTON NOEL BANNER
IPC: B60P1/44
Filed: 1948-10-02
Abstract: 647,817. Load-handling machines; attachments on vehicles for loading. POWER JACKS, Ltd. Oct. 2, 1948, No. 25714. [Classes 78 (iii) and 78 (iv)] An elevating truck carries a superstructure upon which are mounted bell-cranks having long and short arms; the long arms are connected pivotally with a platform and the short arms with an interconnecting link forming two parallelogram linkages so that by applying mechanical lifting means to the system the platform can be raised in such a manner that the parallel linkage formed by the long arms and the platform passes through its position of alignment while the system is still held rigid by the second parallel linkage. A truck chassis a has rear wheels b and front castors c. A rigid superstructure is formed by channel irons d, d<1>, d2 and d3, a touring handle f being pivoted on the irons d. Brackets e on the irons d<2> support a shaft k<1> connected outwardly with bell-cranks each formed by arms k and k<3> welded together, and connected inwardly with bracing arms k<2> to the outer ends of which arms k<3> are welded. Brackets e<1> on the irons d<2> similarly support bell-cranks consisting of arms i and i<9> except that the cranks are wholly between the brackets e<1> on either side. The bracing 'arms k<2> and i<8> of the two bell-cranks are spaced to take a bar n. The connection to arms i<8> is pivotal, whereas the connection to arms k<2> is also pivotal but through an eccentric roller rotatable by means of a lever n<1>. Arms i are extended by arms i<1> welded to them with a bracing tube i<3> at the joint transversely connected. The free ends of arms i<1> are pivotally connected by a further transverse tube i<4> to a shaft fixed on the underside of a platform g, while the free ends of arms k are similarly connected through the medium of a short link m to the front end of the platform. A fluid cylinder a<3> is pivotally connected to a crossmember a' on the chassis, while its piston-rod is pivotally connected to a cross member i<6> between the arms i. On admitting pressure fluid to the cylinder the platform is raised to chain line position. Link m prevents undue strain while crossing the position where the pivots k<1>, e<2>, k<4> and i<4> are in line and lever n<1> is moved to alter the length of bar n to cause tilting of the platform g. A small jib, not shown, may be mounted on the platform to carry a suspended load. A platform vehicle, Fig. 5, is provided with a loading platform consisting of hinged portions v, v<1>, the former portion being adapted to fold up to form a tail board, while the latter portion is supported by two bell-crank levers s, s<1> and t, t<1> pivoted on fixed brackets q<1> and q<2> and connected pivotally by a bar u corresponding to bar n above. The system is operated by a fluid cylinder x so as to raise and lower the loading platform in a way similar to that described above between the ground and the vehicle, a compensating link w being provided as before. A pin may be passed through lugs q<3> on the vehicle chassis and engaged with a lug s<2> on lever s to lock the platform in raised position.