US2941633A - Foldable derrick - Google Patents

Description

June 21, 1960 w. c. HANKs, sR., ETAL 2,941,633

FOLDABLE DERRICK Filed May 14, 1957 2 yous-Sheet 1 INVENTORS WESLEY C. HAN/(S, SR.

RUSSELL E. WILLA/4M5 BY rial June 21, 1960 w. c. HANKS, 5a., ETAL 2,941,633

FOLDABLE DERRICK Filed May 14, 1957 2 Sheets-Sheet 2 R5 5 ms q T K L K 5 WAW N m m wR w United States Patent FOLDABLE DERRICK Wesley C. Hanks, Sr., and Russell E. Williams, San Francisco, Calif.; said Williams assignor to said Hanks Filed May 14, 1957, Ser. No. 659,082

1 Claim. (Cl. 189-16) This invention relates to hoisting devices, and more particularly to an improved foldable and portable derrick which is well adapted for use in roofing work.

An object of the invention is to provide a light weight derrick which is compactly foldable.

A further object of the invention is to provide a roofing derrick which may be readily unfolded for use and folded for carrying and storage.

Still a further object of the invention is to provide a derrick having means enabling the spar member thereof to be easily adjusted both longitudinally and angularly.

Other objectsand advantages of the invention will be apparent from the following description taken in conjunction with the drawings forming part of this specification, and in which:

Figure 1 is a view in side elevation of the subject derrick in unfolded condition for use, the dotted line showing of the same indicating by way of example a different position of adjustment;

Figure 2 is a view in front elevation of the derrick of Figure 1;

Figure 3 is an enlarged detail view in section taken along lines 3-3 of Figure 1;

Figure 4 is an enlarged detail view in section taken along lines 4-4 of Figure 1;

Figure 5 is a view in side elevation of the derrick in folded condition, the dotted line portions illustrating the pre-folded position of certain parts of the derrick;

Figure 6 is a view taken along lines 66 of Figure 5 showing in dotted outline the pre-folded position of certain parts of the derrick; and

Figure 7 is an enlarged detail view in section taken along lines 7-7 of Figure 1.

With reference to the drawings, the derrick comprises an elongated spar member 10 having fixedly secured to its lower end a cross, or stabilizer, member 12 and having secured to its upper end a ring 14 which is adapted to have secured thereto the pulley block, etc. constituting the hoisting apparatus. A split sleeve-like clamp 16 is selectively securable along the spar member, as by bolts 18, extending through apertured flanges 20, and wing nuts 22. Clamp 16 is provided with an integral ear 24 to which the bifurcated upper end of upright support member 26 is pivotally connected by rivet 28.

The lower end of support member 26 is pivotally secured, as by rivet 30, to ear 32 carried by a box channel base member 34. Intermediate the ends of support member 26 there is secured a pair of spaced parallel rigid strap members 36, between the ends of which there is pivotally secured the upper ends of link, or brace, members 38 and 40. The lower end of link member 38 (Figure 7) engages base member 34 adjacent an end thereof, fitting within a complemental semi-socket element 42 which is secured to the base member. The inside surface of the lower end of link member 38 bears against a semisleeve element 44, and a locking pintle 46 telescopically disposed within link member 38 is manually extendable into aperture 48 formed in base member 34 by means of 'ice a handle-stop element 50 which is carried by pintle 46 and extends through slot 52 formed in'the link member.

The upright support member 26 and spar member. 10 are braceably interconnected by means of strut member 54, one end of which is bifurcated and pivotally connected by rivet 56 to car 58 extending from one of the strap members 36, and the other end of which is pivotally connected to a split sleeve-like clamp 60 which is selectively securable along the spar member by a bolt and wing nut assembly such as those previously described ,for clamp 16. v

It will be appreciated that by varying the angularity of strut member with respect to the horizontal, i.e. by varying the distance between the clamps 16 and 60, the angular attitude of the spar member may be varied and the degree of extension of the spar member past clamp 16 may be varied, as indicated by the dotted line showing the derrick in Figure 1. If desired, the derrick may be provided with a head brace as well as a tail brace (strut member 54). In practice, such a head brace has consisted of a strut member having pivotally connected to each end a clamp such as 60, one of said clamps being secured to that portion of the spar member which extends beyond clamp 16 and the other of said clamps being secured to the upright support member 26.

The members 10, 26, 38, 40 and 54 are all formed of aluminum pipe to obtain the desired lightness in weight of the derrick.

When the derrick is in use, it is counterbalanced by such as sand bags, or the like, loaded on the cross member 12 and lower end of the spar member.

To convert the derrick to a folded condition: clamp 60 is loosened; the pintle 46 is slid free of base member 34; link member is swung upwardly against support member 26; the support member is tilted to the left to free link member 40 from semi-socket element 42; link member 40 is swung upwardly against support member 26; base member 34 is swung around to the position shown in Figure 6; and clamp 60 is moved away from clamp 16 to bring members 26, 34, 38, 40 and 54 into substantial parallelism with spar member 10. The folded derrick may then, if desired, have its parts lashed together with a couple of ties of rope, or it may be slung over the shoulder and carried without being tied together.

From the foregoing description of the folding operation, the reverse operation of unfolding the derrick and conditioning it for use will be readily apparent.

What is claimed is:

A foldable derrick adapted for use without fixed anchoring comprising a spar member, an upright member depending from said spar member in supporting relation thereto and having a pivotal connection therewith, means disposed at the lower ends of said spar member and upright members to stably support said derrick in a vertical plane, and a strut member having a pivotal connection with said upright member and with said spar member, said pivotal connection of said strut member with said spar member being adjustably positionable longitudinally of said spar member to enable both adjustment of the anglar attitude of said spar member and the collapsing of said upright member and said strut member into substantial parallelism with said spar member for the carrying and storage of said derrick, said means disposed at the lower end of said upright member comprising an elongated bar member pivotally connected to said upright member and being thereby adapted to be swung into sub stantial parallelism with said upright member, said bar member being positioned for use at right angles to each of said upright, strut and spar members by releasable bracing means, said releasable bracing means comprising a pair of oppositely directed normally downwardly and outwardly inclined link members having their upper ends pivotally connected to said upright member and having their lower ends releasably connected to said bar mem ber adjacent the ends of the latter, said link members being adapted'upon disconnection from said bar member tobe swung into substantial parallelism with said upright member, said bar member having an angularly disposed stop member against which the lower end of one of said link members is adapted to bear 'to prevent pivotal movement of said upright member in the direction of said one link member, the lower end of said other link member being provided with a manually operable extension telescopically related to' saidlink member, said bar member being provided with complemental socket means adapted to receive said extension to thereby prevent pivotal movement of said upright member in the direction of said other link member.

References Cited in the file of this patent UNITED STATES PATENTS 648,402 Haarmann et a1. May 1, 1900 1,298,508 Jerome et a1 Mar. 25, 1919 1,585,961 Blum et al. May 25, 1926 2,343,924 Petersen Mar. 14, 1944 2,830,720 Figge Apr. 15, 1958 FOREIGN PATENTS 141,056 Sweden June 30, 1953

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