US3796018A

US3796018A - Structural elements for the erection of masts, such as hoist and crane masts, antenna masts etc.

Info

Publication number: US3796018A
Application number: US00198390A
Authority: US
Inventors: N Holmstrom
Original assignee: AMACO MASKIN AB
Current assignee: AMACO MASKIN AB
Priority date: 1970-11-13
Filing date: 1971-11-12
Publication date: 1974-03-12
Anticipated expiration: 1991-03-12
Also published as: FR2113922A1; GB1333460A; FR2113922B1; JPS5216328B1; SE348445B; IT940580B; DE2156392A1

Abstract

A hoist mast composed of planar structural elements each consisting of tube means and cantilever means extending therefrom. The tube means has a male member at one end, a female member at the opposite end, which members together form a bayonet catch, a fastening portion and locking means. When at the erection of a mast two tube means are assembled with the aid of the bayonet catch, the end of the cantilever means is swung into engagement with the fastening portion of another tube means and is interlocked with it, and the locking means of the tube means is swung into locking engagement with the fastening portion of a third tube means to prevent unintentional release of a cantilever means engaging the fastening portion.

Description

United States Patent 1191 Holmstrom 1 1 STRUCTURAL ELEMENTS FOR THE ERECTION OF MASTS, SUCH AS HOIST AND CRANE MASTS, ANTENNA MASTS ETC.

[75] Inventor: Nils Felix Folke Holmstrom,

Falsterbo, Sweden [73] Assignee: Amaco Maskin AB, Vellinge,

' Sweden 22 Filed: Nov. 12, 1971 21 Appl. No.; 198,390

[30] Foreign Application Priority Data Nov. 13, 1970 Sweden [5330/70 [52] US. Cl.'. 52/638, 52/646, 52/726, 287/103 A [51] Int. Cl. E04g 7/00 [58] Field of Search 52/638, 645, 721, 726, 52/637, 646, 648; 182/178; 287/103 A; 285/401 [56] References Cited UNITED STATES PATENTS 3,650,078 3/1972 Jennings 52/638 X Mar. 12, 1974 Symons 52/645 Hansen 285/401 X Primary ExaminerI-Ienry C. Sutherland Assistant Examiner-Car1 D. Friedman 57 ABSTRACT A hoist mast composed of planar structural elements each consisting of tube means and cantilever means extending therefrom. The tube means has a male member at one end, a female member at the opposite end, which members together form a bayonet catch, a fastening portion and locking means. When at the erection of a mast two tube means are assembled with the aid of the bayonet catch, the end of the cantilever means is swung into engagement with the fastening portion of another tube means and is interlocked with it, and the locking means of the tube means is swung into locking engagement with the fastening portion of a third tube means to prevent unintentional release of a cantilever means engaging the fastening portion.

5 Claims, 1 Drawing Figure 0/1964 France 182/178- PATENTED MAR l 2 [974 STRUCTURAL ELEMENTS FOR THE ERECTION OF MASTS, SUCH AS HOIST AND CRANE MASTS, ANTENNA MASTS ETC.

This invention relates to a structural element for constructing and erecting masts which are subjected to bending stresses, such as hoist and crane masts, antenna masts and the like, including tube means which at one end has a pin and at the opposite end a conforming hole and intermediate its ends at least one cantilever means.

At building sites use is made to a large extent of building hoists having masts which for tran sport reasons are composed of a number of sections, usu ally of a length of about 1.5 meter sf ln spite of the insigniii ant lengths of the sections the transport thereof is expensive as the sections consist of three or four uprights which are interconnected by means of transverse and diagonal braces and therefore are extremely bulky. It has long been tried to produce planar, readily transportable elements by means of which hoist masts may be assembled and erected, but these attempts have hitherto remained unsuccessful due to the difficulties of assembling the sections in such a way that a stable mast is obtained. A satisfactory stability is imperative. Planar elements are available for the erection of scaffoldings of different kinds, cf. for instance Swedish Patent 201,412, but these elements are not useful for the assembly of hoist masts primarily because they are only intended to support load in one direction, more particularly the longitudinal direction of the scaffolding and therefore have insignificant stability in the transverse direction, whereby they cannot withstand bending stresses. Apart from the requirement for stability and easy transportability structural elements for hoist masts must permit being assembled in a simple manner also by unskilled labour.

The same problems, of course, occur also in crane masts, antenna masts and the like.

The present invention therefore has for its object to provide an element by which the above requirements are satisfied. To this end, the pin and the conforming hole of the tube means are adapted each to form one part of a bayonet catch for interlocking tube means in end-to-end relationship, and the tube means has a fastening portion with which that end of the cantilever means of another corresponding element which faces away from the tube means, is connectible for interlocking purposes by the swinging movement performed upon interconnection of two tube means with the aid of the bayonet catch.

One embodiment of the invention will be more fully described hereinbelow with reference to the accompa-' nying drawing illustrating a perspective view of a hoist mast being erected.

The hoist mast illustrated in the drawing comprises elements A-D which are connected four by four so as to form one section of the hoist mast. This section is connected at the top and bottom to corresponding sections etc. Each element includes a vertically oriented tube means which is of square cross section and on one side and close to its upper end has a cantilever means 1 l which makes a right angle with the longitudinal direction of the tube means 10. For strengthening purposes the cantilever means 11 is connected short of its free end 16 to a brace 12 which extends to a point near the opposite end of the tube means 10. Strengthening means 13 are provided between the brace 12 and the tube means 10. The tube means 10 has end plates 14. A pin generally designated 15 to be described more in detail in the following is arranged on the upper end plate 14, while a hole (not shown) to be described more in detail in the following, is formed in the opposite end plate 14 of the tube means 10. The end 16 of the cantilever means 11 which faces away from the tube means 10 is formed with a through bore 17 which is parallel with the axis of the tube means 10. A fastening having two fork arms 18 is provided on one side of the means 10 which side makes a right angle with that side from which the cantilever means 11 projects. The fork arms 18 are disposed above one another as viewed in the longitudinal direction of the means 10 and have a through bore 19. The end 16 of the cantilever means is insertable between the fork arms and can be fixed in position between them with the aid of a headed bolt 20. At the lower end or the end remote from the cantilever means 11 the tube means 10 has a stud 21 on the same side as and, as viewed in the longitudinal direction of the means 10, opposite to the fork arms 18. Both the cantilever means 11 and the fork arms 18 as well as the stud 21 are of a smaller width than the corresponding side of the tube means 11), whereby all sides of each tube means 10 will be wholly or partly accessible to permit the wheels or rollers of a hoist cage or like device to roll on said sides.

The pins 15 at the upper ends of the tube means 10 each include a stem 23 and projections 22 extending at right angles from the upper end of the stem. In the embodiment illustrated said projections 22 extend at right angles each to one side of the tube means 10. The hole in the end plate 14 at the opposite end of the tube means 10 is formed in a corresponding manner with a central aperture and recesses extending from the periphery thereof and conforming to the projections 22. The dimensions of the aperture and the projections are such that the pin means 15 is easily insertable therein. The recesses of the aperture do not, however, extend like the projections 22 do at right angles to the side surfaces of the means 10 but are oriented at an angle of 45 in relation thereto, that is they extend towards the corners of the means 10. The distance between respectively the underside of the projections 22 and the side thereof facing the adjacent end surface of the means 10 and said end surface corresponds to the distance between the opposite end surface of the means 10 and the underside of the end plate 14. If a tube means 10 is disposed on top of another tube means and is swung an angle of 45 in the horizontal plane relative to the latter.

the pin means 15 can be inserted in a corresponding aperture and then locked in said aperture by rotation of one tube means 10 relative to the other tube means 10 through an angle of 45. The pin means 15 and the corresponding aperture thus constitute a bayonet catch. If necessary, the projections 22 may be so bevelled at the underside, or specific ramp portions may be provided on the inner side of the end plate 14 having the hole, that upon rotation the tube means 10 are tightened in relation to one another.

A hoist mast is erected in the following manner with the aid of the structural elements according to the present invention. It is assumed that a number of elements A-D have already been interconnected; the lowermost elements of the hoist mast are placed on a specific base provided for that purpose. A first element A is then placed on top of another element but swung an angle of 45 in relation to said other element in the end plane of the elements. The pin means of the subjacent element can then be inserted in the conforming hole in the lower end plate 14 of the element A. The two elements are interlocked by rotation through an angle of 45 to make the side surfaces of the element A coincide with those of the subjacent element. As a result of said rotation the stud 21 is brought in position above the bolt in a subjacent fastening, whereby the bolt 20 cannot be loosened. A further element B is then mounted and swung inward into position whereby the fork arms 18 will be moved in over the end 16 of the cantilever means 1 1 of the element A and a bolt 20 can be passed through the bores 19 of the fork arms 18 and the bore 17 in the end 16 of the cantilever means 11 to lock said end. When the element B is swung inward the bolt 20 of an underlying fastening 18 will be locked by means of the stud 21 in the same way as when the element A is swung inward. After that the elements C and D are swung inward in the same way and secured in position. The end 16 of the cantilever means on the last element D is connected with the fastening 18 of the element A. After all four elements A'D have been fastened another element A is disposed on top of the 'earlier element A and swung inward into position, and so forth. It will be realized that a hoist mast can be erected in an extremely simple manner with the aid of the elements described.

Of course the cantilever means 11 need not project at right angles from the tube means 10 but can make another angle with the longitudinal direction of said means 10. The cantilever means 11 need not either be strengthened in the manner illustrated. Also, the fastening need not necessarily have two arms 18 as one arm may be sufficient in certain cases. The position of the stud 21 forming the locking means, naturally is dependent upon the orientation and position of the cantilever means 11 and can therefore have various configurations and be provided on both the tube means 10 and some strengthening means of the element. In other words, the invention should not be considered limited to the embodiment described above and illustrated in the drawing as it can be modified within the scope of the appended claims.

What I claim and desire to secure by Letters Patent l. A structural mast having at least three sides and composed of a plurality of identical interengagable structural elements, each element comprising a longitudinal member provided with a male bayonet means at one end and a female bayonet means at the other end, the male bayonet means of a first longitudinal member being securely engaged to the femal bayonet means of a second longitudinal member by relative axial rotation to be coaligned therewith, each longitudinal member being provided with a cantilever means including an upper cantilever arm extending outwardly substantially normal to said longitudinal member a brace means extending upwardly from said longitudinal member to the outer end of said cantilever arm, a first locking means disposed at the outer end of said cantilever arm, a second locking means disposed at one end of said longitudinal member adjacent the inner end of said cantilever arm, and a third locking means disposed at the end of said longitudinal member opposed from said second locking means and in the same vertical plane as said second locking means, the first locking means at the end of the cantilever arm of the first longitudinal member engaging the second locking means of a third longitudinal member disposed laterally of said first longitudinal member and pin means securing the engagement of said first and second locking means, and the third locking means of a fourth longitudinal member engaged coextensively with said third longitudinal member preventing removal of said pin means securing the engagement of the first and second locking means of the first and third longitudinal member respectively.

2. A structural mast as claimed in claim 1 wherein said male bayonet means comprises a pin extending in the longitudinal direction of the longitudinal member and having adjacent its free end projections extending transversely of the longitudinal member, said female bayonet member comprising an end plate fastened at the opposed end of the longitudinal member and provided with a hole therein and having recesses extending outwardly from the periphery of the hole through which said projections may be passed, said recesses being oriented at least 30 offset in their end plane in relation to the projections so that two of said longitudinal members are interlocked by engagement of said projections with the underside of said end plate.

3. A structural mast as claimed in claim 1, wherein said first locking means includes a bore therethrough, and said second locking means including two fork arms each having a bore therethrough, said first locking means being inserted between the fork arms so that its bore registers with the bores in said fork arms, said pin means being inserted in said bores.

4. A structural mast as claimed in claim 1, wherein said second locking means on the third longitudinal member is disposed in an axial plane at an angle to the axial plane of the cantilever means on said third member and is in alignment with said first locking means on said first longitudinal member.

5. A structural mast as claimed in claim 1, wherein said third locking means comprises a stud.

Claims

1. A structural mast having at least three sides and composed of a plurality of identical interengagable structural elements, each element comprising a longitudinal member provided with a male bayonet means at one end and a female bayonet means at the other end, the male bayonet means of a first longitudinal member being securely engaged to the femal bayonet means of a second longitudinal member by relative axial rotation to be coaligned therewith, each longitudinal member being provided with a cantilever means including an upper cantilever arm extending outwardly substantially normal to said longitudinal member and a brace means extending upwardly from said longitudinal member to the outer end of said cantilever arm, a first locking means disposed at the outer end of said cantilever arm, a second locking means disposed at one end of said longitudinal member adjacent the inner end of said cantilever arm, and a third locking means disposed at the end of said longitudinal member opposed from said second locking means and in the same vertical plane as said second locking means, the first locking means at the end of the cantilever arm of the first longitudinal member engaging the second locking means of a third longitudinal member disposed laterally of said first longitudinal member and pin means securing the engagement of saiD first and second locking means, and the third locking means of a fourth longitudinal member engaged coextensively with said third longitudinal member preventing removal of said pin means securing the engagement of the first and second locking means of the first and third longitudinal member respectively.

2. A structural mast as claimed in claim 1 wherein said male bayonet means comprises a pin extending in the longitudinal direction of the longitudinal member and having adjacent its free end projections extending transversely of the longitudinal member, said female bayonet member comprising an end plate fastened at the opposed end of the longitudinal member and provided with a hole therein and having recesses extending outwardly from the periphery of the hole through which said projections may be passed, said recesses being oriented at least 30* offset in their end plane in relation to the projections so that two of said longitudinal members are interlocked by engagement of said projections with the underside of said end plate.