US 6,296,288 B1Grant
Spreader bar apparatus
Issue Date:2001-10-02
•33 Claims
•4 Drawing Sheets
Abstract
A spreader bar apparatus of improved configuration is comprised of a plurality of bar sections including at least a pair of bar sections that are connectable end-to-end to form a lifting bar with a central longitudinal axis and with left and right bar end members, each removably attachable to the lifting bar that is comprised of the two bar sections. A plurality of transverse annular faces are provided respectively on the bar sections and on the bar end members for transferring axial load along the bar central axis and in between the various bar sections and end members during a lift. A plurality of connecting portions provided on the bar sections and bar end members form detachable connections between the bar sections and between each bar end member and a bar section. The apparatus of the present invention is so configured that a majority of load is carried by the annular faces as opposed to the connecting portions. For example, threaded connections can be used to assemble the bar sections and end members together. However, the thread sections are loosely connected until the annular faces abut one another so that a full engagement of the threads is not realized and the annular faces carry substantially all or most of the load.
Metadata
Inventor
- Jon E. Khachaturian
Application Information
Application Number:US 09/604,339
Filing Date:2000-06-27
Priority Date:1998-06-25
Art Unit:7
Classifications
IPC:
B66C 112
Field of Search:
294 811294 812294 8121294 815294 816294 74294 11294 8154294 8162
Patent Drawings (4 sheets)
Description
Cross-Reference to Related Applications
[0002] This is a continuation of U.S. Ser. No. 09/104,513, filed Jun. 25, 1998, and entitled “SPREADER BAR APPARATUS” now U.S. Pat. No. 6,079,760.
Statement Regarding Federally Sponsored Research or Development
[0003] Not applicable
Reference to a “Microfiche Appendix”
[0004] Not applicable
Background of the Invention
[0005] 1. Field of the Invention
[0006] The present invention relates to lifting apparatus and accessories, and more particularly to an improved spreader bar lifting apparatus for use with cranes and other lifting devices that use slings. Even more particularly the present invention relates to an improved multi-part spreader bar arrangement that includes a plurality of connectable sections including at least a pair of bar sections and a pair of end members, and wherein the detachable connections between the sections are provided with annular load bearing faces that carry a majority of the axial compressive load during use.
[0007] 2. General Background of the Invention
[0008] Spreader bars are commonly used in industry for lifting large objects with a single hook that is attached to the crown block and lift cables of a crane. A lifting hook is commonly provided with a pair of slings that depend from the crane hook at angles in a bridle fashion, each of the slings connecting to an end portion of the spreader bar. Parallel, depending lift lines are then suspended from the end portions of the spreader bar downwardly to the load that is to be lifted. An example of a spreader bar that has been patented can be seen in my prior U.S. Pat. No. 4,397,493, and entitled “Spreader Bar Assembly”.
[0009] One of the problems with spreader bars is that of sizing the spreader bar to meet a particular load. Some devices have attempted to provide telescoping sections in order to adjust the spreader bar to different lengths so as to accommodate different loads. Such a telescoping, locking spreader bar operates well for relative light loads of a few thousand pounds. However, in the lifting of extremely heavy objects such as, for example, 25-50 tons, a much more rugged construction is required.
[0010] Another problem that faces the user of a spreader bar is that of transporting the bar from one place to another at a construction facility, fabrication yard, plant, shop, or the like. Most spreader bars are extremely heavy when compared to the strength of an average worker. To lift a very heavy object, one has typically needed a very heavy spreader bar. This creates a hazardous condition when workers attempt to move a very heavy spreader bar from one location to another.
Brief Summary of the Invention
[0011] The present invention provides an improved spreader bar apparatus that can lift very heavy loads and at the same time be constructed of relatively lightweight material so that a high ratio is provided of load capacity to spreader bar weight.
[0012] This solves the problem of providing a very high capacity spreader bar that can be moved from one location to another by a worker or a few workers and avoiding the risk of injury.
[0013] The present invention provides a spreader bar apparatus of improved construction that can be disassembled for transport to remote locations using less expensive transportation means such as parcel service, mails, or the like.
[0014] The present invention provides an improved spreader bar apparatus that is constructed of a plurality of bar sections and a plurality of end members that are attachable end-to-end to form a single, rugged spreader bar assembly.
[0015] In the preferred embodiment, the plurality of bar sections and end members are attached using removable (preferably threaded) connections to assemble the bar sections and end members end-to-end.
[0016] In order to prevent substantial stress at the interface between one threaded section and another, the present invention provides transverse annular faces for transferring axial load along the bar central axis and in between the connected bar sections and bar end members. These load transfer faces preferably carry at least half of the load (and preferably substantially all of the load) so that the threads are not damaged during use.
[0017] The spreader bar apparatus of the present invention thus provides an improved spreader bar apparatus having a load carrying capacity and a bar weight, with the ratio of the load carrying capacity to the bar weight being between about 800 to 1 and 1200 to 1.
[0018] The bar and bar end members are preferably of a material having a density of between about 150 and 200. In the preferred embodiment, the bar sections and bar end members are of an aluminum material or an aluminum alloy. A carbon composite could also be used.
[0019] The interconnections between bar sections and end members is preferably a threaded type connection. However, other types of detachable connections can be used to assemble bar sections together and end members to bar sections such as, for example, bayonet-type connections or taper lock or wedge lock type connections.
[0020] The present invention provides an improved spreader bar apparatus with annular load carrying faces that can in fact carry substantially all of the axial load in the bar during a lift, thus insulating the connecting portions (for example threads) from substantial stress during the lift.
[0021] The apparatus of the present invention includes end members that have sling receiving portions for enabling slings to be rigged to the bar end members.
Brief Description of the Drawings
[0022] For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
[0023] FIG. 1 is a perspective view of the preferred embodiment of the apparatus of the present invention;
[0024] FIG. 2 is a perspective fragmentary view of the preferred embodiment of the apparatus of the present invention illustrating the end member portions thereof;
[0025] FIG. 3 is an exploded perspective view of the preferred embodiment of the apparatus of the present invention;
[0026] FIG. 4 is a top, sectional view of the preferred embodiment of the apparatus of the present invention;
[0027] FIG. 5 is a side elevational view of the preferred embodiment of the apparatus of the present invention illustrating one of the end members having a female socket portion thereon;
[0028] FIG. 6 is an end view of the end member of FIG. 5;
[0029] FIG. 7 is a top view of the end member of FIGS. 5-6;
[0030] FIG. 8 is an end view of the end member of FIGS. 5-7;
[0031] FIG. 9 is a side elevational view of the preferred embodiment of the apparatus of the present invention illustrating an end member portion thereof having a projecting connector member;
[0032] FIG. 10 is an end view of the end member of FIG. 9;
[0033] FIG. 11 is a top view of the end member of FIGS. 9-10; and
[0034] FIG. 12 is an end view of the end member of FIGS. 9-11.
Detailed Description of the Invention
[0035] FIGS. 1-4 show generally the preferred embodiment of the apparatus of the present invention designated generally by the numeral in FIGS. 1, 3, and 4. Spreader bar apparatus 10 is shown in FIG. 1 attached to a crane lifting hook 11 with a plurality of slings 12-15. Such slings 12-15 are known in the art and are constructed of a number of different materials such as wire rope, polymeric woven plastic, plastic webbing, and like materials.
[0036] The apparatus 10 includes a plurality of connectable bar 10 sections 16, 17 that are connected end-to-end. End members 18, 19 are assembled respectively to the bar sections 16 and 17 as shown in FIGS. 1, 3, and 4. Each end member 18, 19 can be constructed of a body with a plurality of plates having openings through which a pin 20 or 21 can be inserted as shown in FIGS. 1, 2, 3, and 4. The particular construction of the end members 18, 19 is shown in FIGS. 5-12.
[0037] In FIG. 1, a pair of slings 12, 13 are rigged to end member 18. Pin 20 extends through openings 48 and plates 39, 40, 41, 42. Slings 14 and 15 are rigged to end member 19. The pin 21 extends through opening 48 in plates 49, 50, 51, 52 of end member 19. In FIG. 4, the pins 20, 21 can be single pin members that extend through openings 48 in the respective plates of end members 18, 19 as shown.
[0038] Depending slings 22 and 23 are rigged at the center of each pin 20, 21 as shown in FIG. 4. The slings 12 and 13 are rigged on opposing sides of the sling 22. For the end member 19, the slings 14, 15 are rigged on opposite sides of the sling 23 as shown. Each of the slings is positioned in between a pair of adjacent plates of the respective end members 18 and 19. The sling 12 is in between plates 39 and 40. The sling 22 is in between the plates 40 and 41. The sling 13 is in between the plates 41 and 42.
[0039] An assembly of the bar sections 16, 17, 18, 19 can be seen in FIG. 4. The bar section 16 includes larger diameter section 24, smaller diameter section 26, and larger diameter section 28. The bar section 17 includes larger diameter section 29, smaller diameter section 27, and enlarged diameter section 25. The enlarged diameter sections provide annular transverse faces that are load bearing faces for transferring substantially all of the axial load from one bar section 16 to the next bar section 17 along the central longitudinal axis of the bar apparatus 10, designated by the dotted line X—X in FIG. 4. Further, annular transverse load carrying faces are used to transfer load in between a bar section 16 and its end member 18. Transverse faces are used to transfer load between bar section 17 and its end member 19. These annular transverse faces are seen more particularly in the detailed views of FIGS. 3 and 5-12.
[0040] In FIGS. 3 and 5-12, the bar section 16 provides an annular transverse face 30 and opposite annular transverse face 31. The bar section 17 provides an annular transverse face 32 and opposite annular transverse face 33. The bar section 16 provides an externally threaded projecting portion 34 next to annular transverse face 30.
[0041] An internally threaded socket 35 is provided at the end of bar section 16 opposite projecting portion 34. The bar section 17 provides an externally threaded projecting portion 36 at one end portion thereof and an internally threaded socket 37 at the other end portion thereof as shown in FIGS. 3 and 4.
[0042] Each of the end members 18 and 19 provides connecting portions that form threadable connections in the preferred embodiment with the ends of the assembled bar sections 16 and 17, as shown in FIGS. 3 and 4. End member 18 as shown in FIGS. 5-8 is formed of a body 18 and a plurality of plates 39, 40, 41, 42 extending therefrom as shown in FIGS. 5-8. A transverse annular face 43 forms a load transfer interface with a correspondingly shaped transverse annular face 30 of bar section 16 as shown in FIG. 4.
[0043] The end member 18 has an internally threaded socket 44 that includes a circular transverse face 45. The transverse circular face 45 registers against a correspondingly shaped flat surface 46 of projecting end portion 34 of bar section 16 as shown in FIGS. 3 and 4. These circular transverse faces 45 and 46 engage one another when the bar is operating for transferring load there between. Similarly, the other abutting annular transverse faces transfer load during a lift. The threads on the projecting end portions and on the sockets of the various end members and bar sections are configured to loosely assemble the bar sections 16, 17 and end members 18, 19 together end-to-end as shown in FIG. 4. In this fashion, the transverse annular faces and circular transverse faces carry substantially all of the load thus insulating the threads from substantial stress. In the preferred embodiment, these transverse annular faces and the circular transverse faces carry at least half (and preferably all) of the load.
[0044] A flat surface 47 of body 38 communicates with the plurality of plates 39, 40, 41, 42 as shown in FIGS. 5-8. This provides recesses next to the flat surface 47 and in between the various plates 39, 40, 41, 42 as shown in FIGS. 7 and 8. As shown in FIG. 4, the slings 12-15 and 22-23 are rigged in the spaces provided in between the plates 39-42 of end member 18 and in between the plates 49, 50, 51, 52 of the end member 19 shown in FIGS. 9-12.
[0045] In FIGS. 9-12, the end member 19 is constructed similarly to the end member 18 of FIGS. 5-8, the difference being the providing of a projecting connecting portion 56 having a transverse circular face 57. This projecting portion 56 forms a threaded connection with the internally threaded socket 37 of bar section 17 as shown in FIG. 4. End member 19 is thus comprised of a body 58 having a projecting portion 56 extending there m at generally right angles to annular transverse face 59.
[0046] Body 58 provides a flat surface 60 from which a plurality of plates 49, 50, 51, 52 extend at generally right angles as shown in FIGS. 11 and 12. These plurality of plates 49, 50, 51, 52 provide spaces there between that enable slings 14, 15 and 23 to be rigged to the pin 21 that extends through opening 48 as shown in FIGS. 3-4 and 9-12.
[0047] The circular arrows 53, 54, 55 in FIG. 3 schematically represent the circular motion of each of the bar sections 16 and 17 when they are threadably connected together (see arrow 55) and a connection of an end member 18 to bar section 16 (see arrow 53) and the connection of end member 19 to bar section 17 (see arrow 54).
[0048] The present invention provides a great load carrying capacity for enabling spreader bar 10 to lift a large amount of weight when compared to the weight of the bar 10 itself. Because of the particular construction of the apparatus of the present invention, relatively lightweight metals or like materials can be used in its construction, for example, so that a very high ratio exists between the load carrying capacity of a bar and its bar weight. In the preferred embodiment, this ratio is about 1000 to 1. As an example, an aluminum bar has been constructed in accordance with the aforedescribed specification and drawings that has a load carrying capacity of about 50,000 pounds and a bar weight of 50 pounds for a ratio of 1000 to 1.
[0049] The following table lists the parts numbers and parts descriptions as used herein and in the drawings attached hereto.
[0050] the foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.
Claims
What is claimed is:
1. A spreader bar apparatus comprising:
a) a pair of bar sections that are connectable end-to-end to form a lifting bar with a bar central longitudinal axis;
b) left and right bar end members each removably attachable to the lifting bar;
c) a plurality of transverse mating annular faces provided on both the bar sections and the bar end members for transferring axial load along the bar central axis in between bar sections and bar end members;
d) a plurality of longitudinally extending interlocking connecting portions provided respectively on the bar sections and bar end members for forming detachable connections between bar sections and between the bar end member and the bar section;
e) wherein said connecting portions are defined by correspondingly shaped projecting portions and socket portions, a projecting portion mating with a socket portion when the bar section is connected to said another section or to the bar end member, the projecting portion having an outwardly facing and longitudinally extending surface having one of said interlocking connecting portions thereon that extends longitudinally a distance, and the socket portion having an inwardly facing, longitudinally extending surface having one of said interlocking connecting portions thereon that extends longitudinally a distance; and
f) wherein load transfer occurs at the transverse mating faces to define a means for protecting the interlocking connecting portions.
2. The spreader bar apparatus of claim 1 wherein the bar has a load carrying capacity and a bar weight and the ratio of load carrying capacity to bar weight is at least one thousand to one.
3. The spreader bar apparatus of claim 2 wherein the bar and bar end members are of a material having a density of less than 400 lbs. per cubic foot.
4. The spreader bar apparatus of claim 2 wherein the bar sections and bar end members are of an aluminum material.
5. The spreader bar apparatus of claim 1 wherein the bar has a load carrying capacity and a bar weight is between about 800 to 1 and 1200 to 1.
6. The spreader bar apparatus of claim 5 wherein the bar and bar end members are of a material having a density of less than 300 lbs. per cubic foot.
7. The spreader bar apparatus of claim 5 wherein the bar and bar end members are of a material having a density of less than 200 lbs. per cubic foot.
8. The spreader bar apparatus of claim 5 wherein the bar sections and bar end members are of an aluminum material.
9. The spreader bar apparatus of claim 1 wherein the interlocking connecting portions include threaded connections.
10. The spreader bar apparatus of claim 9 wherein the threaded connections include corresponding internal and external threaded portions that engage upon assembly.
11. The spreader bar apparatus of claim 10 wherein the annular faces carry more axial load than the threaded portions.
12. The spreader bar apparatus of claim 11 wherein the annular faces carry substantially all of the axial load.
13. The spreader bar apparatus of claim 1 further comprising pins carried by each end member that enable slings to be rigged to the bar end members at the pins.
14. The spreader bar of claim 1 wherein the end members include openings for holding a pin to which rigging can be attached.
15. A spreader bar apparatus comprising:
a) a segmented bar body that includes a central portion and left and right end portions;
b) the central portion comprising at least a pair of bar sections including at least a left bar section and a right bar section, the bar sections being connectable together end-to-end at a central connection near the central portion of the bar body and detachable at said central connection;
c) the left end portion providing a left end member that is removably connectable to the left bar;
d) the right end portion providing a right end member that is removably connectable to the right bar section;
e) the connections including threaded engaging portions that assemble each end member to a bar section;
f) corresponding transverse engaging surfaces that carry substantially all of the axial load at the interface between each end member and its bar section so that the threaded engaging portions are protected from damage during a lift.
16. The spreader bar apparatus of claim 15 wherein the bar and bar end members are of a material having a density of less than 400 lbs. per cubic foot.
17. The spreader bar apparatus of claim 15 wherein the bar and bar end members are of a material having a density of less than 300 lbs. per cubic foot.
18. The spreader bar apparatus of claim 15 wherein the bar and bar end members are of a material having a density of less than 200 lbs. per cubic foot.
19. A spreader bar apparatus comprising:
a) a pair of bar sections that are connectable end-to-end to form a lifting bar with a bar central longitudinal axis;
b) left and right bar end members each removably attachable to the lifting bar;
c) a plurality of transverse mating annular faces provided on both the bar sections and the bar end members for transferring axial load along the bar central axis in between bar sections and bar end members;
d) a plurality of longitudinally extending interlocking threaded connecting portions provided respectively on the bar sections and bar end members for forming detachable connections between bar sections and between a bar end member and a bar section; and
e) wherein load transfer occurs at the transverse mating faces to define a means for protecting the interlocking threaded connecting portions.
20. The spreader bar apparatus of claim 19 wherein the bar has a load carrying capacity and a bar weight and the ratio of load carrying capacity to bar weight is at least one thousand to one.
21. The spreader bar apparatus of claim 19 wherein the bar has a load carrying capacity and a bar weight is between about 800 to 1 and 1200 to 1.
22. The spreader bar apparatus of claim 19 wherein the bar and bar end members are of a material having a density of less than 400 lbs. per cubic foot.
23. The spreader bar apparatus of claim 19 wherein the bar and bar end members are of a material having a density of less than 300 lbs. per cubic foot.
24. The spreader bar apparatus of claim 19 wherein the bar and bar end members are of a material having a density of less than 200 lbs. per cubic foot.
25. The spreader bar apparatus of claim 19 wherein the bar sections and bar end members are of an aluminum material.
26. The spreader bar apparatus of claim 19 wherein the threaded connections include corresponding internal and external threaded portions that engage upon assembly.
27. The spreader bar apparatus of claim 19 wherein the annular faces carry more axial load than the threaded portions.
28. The spreader bar apparatus of claim 19 wherein the annular faces carry substantially all of the axial load.
29. The spreader bar apparatus of claim 19 further comprising pins carried by each end member that enable slings to be rigged to the bar end members at the pins.
30. The spreader bar of claim 19 wherein the end members include openings for holding a pin to which rigging can be attached.
31. The spreader bar apparatus of claim 19 wherein the bar and bar end members are of a material having a density of less than 400 lbs. per cubic foot.
32. The spreader bar apparatus of claim 19 wherein the bar and bar end members are of a material having a density of less than 300 lbs. per cubic foot.
33. The spreader bar apparatus of claim 19 wherein the bar and end members are of a material having a density of less than 200 lbs. per cubic foot.
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