US 2941634 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
June 21, 1960 Filed May 14, 1957 w. c. BANKS, sR., ETAL 2,941,634
A-FRAME aozsrmc DEVICE 2 Sheets-Sheet 1 INVENTORS WESLEY C. HAN/(5,573. RUSSELL E. WILLIAMS ATTORNEYS June 21,1960 w. c. HANKS. 5a., ETAL 5 A-FRAME uorsmc mavrcz Filed May 14, 1957 2 Sheets-Sheet 2 INVENTORS WESLEY C. HAN/(S, SR RUSSELL E. WILLIAMS A 7' TOPNEYS Un w st P w-fi 2,941,634 A-FRAME HOISTING DEVICE Filed May 14, 1951, Ser. No. 659,083
a z Cl. 189-16) This invention relates to hoisting devices, and more particularly to an improved A-frame type of hoisting device which is particularly adapted for use in roofing work, i.e. for, the hoisting of building and repair materials from ground level to the roof or top of a building.
It is conventional in connection with roofing work to employ jerry-built A-frames made of pieces of wood nailed together for the purpose of lifting the roofing materials to the site of the work to be done. Such frames are bulky, quite heavy, and'require the full efforts of an individual workman to carry them up to where they are to be set up for use. The full pre-occupation of at least one workman with such a frame makes the overall job set-up and take-down programs more difficult and time consuming than would be the case if the person having the job of toting the frame were able to carry other items of equipment along with the frame.
The essential object of the present invention is to provide a strong, light weight compactable A-frame which can be readily assembled for use and disassembled for simple over-the-shoulder carrying to and from the job. A workman carrying the subject frame may readily carry other items of equipment or material along with it, and, furthermore, the frame may be assembled or disassembled in a matter of seconds.
This and other objects and 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 hoisting device in assembled and positioned condition for use;
Figure 2 is a view in front elevation of said hoisting device;
Figure 3 is a view in elevation of said hoisting device in disassembled and compacted condition for carrying or storage;
ed on sleeve section 22, between bearing and guide rings 28 secured to said section, is a ring 29 which has secured to it another ring 30, the latter being adapted to serve as a tie-ring support for a pulley block, such as thatindicated at 32 in Figure 1.
, Cross bar 16 has an end of reduced thickness pivotally secured between a pair of cars 34 secured to leg '12. The other end of bar 16 terminates in a clevis 36 within which there is disposed, and pivotally secured-by rivet 38, an ear 40 forming part of a clamp indicated generally at 42. The clamp 42 comprises (Figure 5) a pair of complemental semi-cylindrical sections 44 and 46 adapted to 'clampingly embrace leg 10. Said sections 44 and 46 are pivotally connected together by a hinge pin 48 and they are adapted to be clamped together by means comprising: a pair of ears 50 integral with section 46; a bolt '52 pivotally secured between ears 50 by pin 54; a pair of spaced apart lugs 56 integral with section 44, between which lugs bolt 52 is adapted to extend; a cylindrical cross bar 58 slidably disposed on bolt 52 and adapted when pressed against the convex surfaces 60 of lugs 56 to secure the bolt 52 in its locking position; and a wing nut 62 on the threaded end of bolt 52 adapted 'to press the cross bar'58 againstthe convex surfaces 60. i
The legs 10 and 12 have secured to the lower ends thereof ball and socket mounted foot pads 64.
Figure 3 illustrates the disassembled condition of the A-frame, in which condition it is adapted to be slung Figure 4 is an enlarged detail View in perspective of m the upper portion of said device, the parts of said upper portion being shown in disconnected relation;
Figure 5 is an enlarged detail view in section taken along lines 5-5 of Figure 2;
Figure 6 is a view in front elevation of a modified form of the hoisting device; and
Figure 7 is an enlarged detail view in section taken along lines 77 of Figure 6, but showing the clamp element in an open condition.
With reference to Figure 2, the A-frame comprises legs 10 and 12, an upper cross bar 14 interconnecting said legs at the upper ends thereof, and a bracing cross bar 16 interconnecting said legs adjacent the lower ends thereof. Cross bar 14 is comprised of section 18 integral with leg 10, section 20 integral with leg 12, and a sleeve section 22 fixedly secured over the end of section 18 and adapted to receive the end of section 20. Sleeve section 22 is provided with a pair of bayonet slots 24 adapted to receive the pair of pins 26 carried by section 20 and lock the bar sections together. Rotatably mountacross a persons shoulder for convenient carrying to the roof where it is tobe used. It will be noted that the clamp 42 is secured to leg 12, thereby preventing any flopping about or relative movement of the cross bar 16 with respect to leg 12 while the equipment is being carried. The legs and cross bars of the frame are formed of aluminum pipe in order that the frame may be made as light as possible while being sufliciently strong to handle the loads required.
On the roof 66 (Figure 1), the A-frame is readily and quickly assembled and positioned for use in the following manner: the pins 26 are introduced fully into the slots 24 and the sections 18 and 20 are axially rotated relative to each other to lock the bayonet joint; the clamp 42 is disconnected from leg 12 and connected to leg 10 after the cross bar 16 has been swung down to a horizontal position; nails are driven through apertures provided in foot pads 64 to fixedly secure these pads in the desired position; an anchor rope 68 is tied to loop 70 (Figure 4) carried bysleeve section 22 and tied around a chimney, or secured to such as an anchor ring 72, to secure the frame in the desired angular attitude for use; and pulley block 32 is connected to tie ring 30. The desired materials and equipment may then be hoisted up to the roof for use.
A slightly modified form of the A-frame is shown in Figures 67 wherein parts and elements corresponding to those previously described in connection with the preferred embodiment of the frame are designated by the same reference numerals plus 100. Thus, leg 10 of the previously described frame becomes leg of this frame, and so on. The only differences between the preferred form and the modified form of the frame are as follows: clamp 142' is fixedly secured to cross bar 16; clamp section 144 is provided with a short pin (Figure 7) adapted to fit within an aperture 182 formed in leg 110 when the clamp is closed, thus ensuring that the clamp will be secured in the same position ,each time and not in an offset position which could impart a warped condition to the frame elements; and leg 112 is provided with a stub arm 184 to which the clamp 142 is secured when the frame is in disassembled condition.
It will be appreciated that when the cross bars, or transverse bracing members, 16 and 116 are in connecting relation with the leg members of the A-frame, sufiicient relative rotative movement of the sections, or extensions, 118 and 120 to enable disconnection of the bayonet joint is prevented. I '.,Having thus described the lifting frame of the invention, what ;we claim as new and desire to secure by Letters Patent is: v r
1. An A-frame hoisting device comprising first and second elongated leg members having inwardly directed axially aligned extensions at the upper ends thereof, complemental locking means embodied in said extensions at the inner ends thereof releasably connecting said extensions together, and a transverse bracing member interconnecting said leg members at opposite points and being operable when so disposed to prevent the unlocking of said locking means, one end of said bracing member having a'permanent and pivotal connect-ion with said first leg member adapting said bracing member to be swung into parallel relation withsai-d leg member, the other end of said bracing member having a clamp formed of hinged-together and releasably locked complemental sections disposed in gripping relation with said second leg member, said clamp having a pivotal connection with said bracing memberadapting said clamp to be secured to saidfirst leg member with said bracing members swung into parallel relation with said first leg member.
2. An A -frame hoisting device comprising first and second elongated leg members having inwardly directed axially aligned extensions at the upper ends thereof, complemental locking means embodied in said extensions at the inner ends thereof releasably connecting said extensions together, and a transverse bracing member interconnecting said leg members at opposite points and being operable when so disposed to prevent the unlocking of said locking means, one end of said bracing member having a permanent and pivotal connect-ion with said first leg member adapting said bracing member "to be swung into parallel relation with said leg member, the other end of said bracing member having a clamp formed-ofhinged-together and releasably locked complementalsections disposed in gripping relation with said second leg member, said clamp having .a fixed connection with said bracing member, and an abbreviated arm member extending inwardly from said first leg member to Which said clamp may be secured when said bracing member is swung into parallel relation with said first leg member.
References Cited in the file of this patent UNITED STATES PATENTS 562,532 -Hartzell June 23, 1896 v706,176 Hassett Aug. 5, 1902 1,461,426 1 Lisowski July 10, 1923 1,583,442 Broadhead May 4, 1926 1,985,024 Douglas Dec. 18, 1934 2,825,115 Williams Mar. 4, 1958