GB1001388A - Derrick - Google Patents

Abstract

1,001,388. Mobile cranes, loading and unloading. OHIO BRASS CO. Nov. 2, 1962, No. 41555/62. Headings B8B and B8E. [Also in Division E1] A portable derrick 12, particularly for handling and erecting telegraph poles, on which may be mounted work tools such as earth boring tools, is mounted on a vehicle 10 and comprises a telescopic boom 24 swing- able in a vertical plane and rotatable in a horizontal plane. The boom 24 has an inner portion 22 and an outer portion 26 having a sheath assembly 26a, mounted thereon by rollers 26b, 26c, Fig. 4, and extendable by a fluid powered unit 28. Portion 22 is pivoted at 19 to a swivel head 60 and a base 40 and can be swung into vertical plane from a storage position shown in solid lines in Fig. 1 to load supporting positions shown in chain lines by a ram unit 32 pivoted at 42 to brackets 27 of the portion 26 and at 44 to an arm 34 pivoted in turn at 34a to a bracket 34b and at 38a to links 38 connected at 40 to the portion 22. The boom is swung from a working pole erecting position 26a<SP>1</SP>, Fig. 6, to a vehicle loading position 26a<SP>11</SP> by a ram 54 acting on a linkage 56, 58 connected between an arm 16b of the head 16 and a bracket 50 secured to a stationary portion 18 of the base. A tool such as an earth borer can be attached to an arm 78, Fig. 7, of a supporting member 76 which is in the form of a collar encompassing the extendable portion 26. The member 76 can be locked to the outer portion 26 by a spring-loaded plunger 94 entering an opening therein or can be retained on the inner portion 22 by a latch 104 which in operative position cams the plunger 94 out of engagement with the portion 26. Ram-operated outriggers are provided. Specification 1,001,389 is referred to.