CARRIER TRACK SYSTEM FOR EXTENSIBLE AND RETRACTABLE BOOM MACHINES

Abstract: To guide and restrain essential hoses and cables of telescoping boom machines, a carrier track system for the hoses and cables is provided in which all parts of the flexible carrier track are supported during extension and retraction of the telescoping boom. The system includes a stiff leg (20) attached to the forward end of the boom fly section (17) and extending rearwardly thereof and engaging a guiding and restraining device on the forward end of a carrier track bridge (29) attached to the forward end of the boom mid-section (16) and extending rearwardly thereof and engaging a restraining and guiding device on the forward end of the boom base section (14). The rear of the bridge carries a guide roller assembly (34) which engages the bight portion (37) of the flexible carrier track (38) which is connected between the stiff leg and the forward end of the boom base section. Spaced support rollers (52) on the top of the bridge engage and support the stiff leg and the top stretch (50) of the flexible carrier track along its entire length. The bottom stretch (49) of the flexible carrier track is supported along its entire length by spaced support elements (51) along the bottom of the boom base section. The rear end of the bridge is supported through its attached guide roller assembly on the supported lower stretch of the flexible carrier track.

Description: Technical Field - The present invention relates to an improved guide and restraint system for flexible hoses and cables employed on telescoping boom machines, such as aerial work platforms. United States Patent Specification Number US-A-4 506 480 describes a carrier track system for a multi-section extensible and retractable structure including a single length of flexible carrier track having its opposite ends connected between a pair of relatively movable sections of the extensible and retractable structure, the carrier track having a rolling portion and spaced substantially parallel stretches which vary in their lengths in response to extension and retraction of the structure. A disadvantage of the carrier track system of US-A-4 506 480 is that no means are specifically provided to support the parallel stretches substantially along their entire length in all adjusted positions of the track. It can be seen, for example, from US-A-4 506 480 that if an upper stretch of the track sagged sufficiently it would contact a lower wear pad which would support it. However, this is not the primary function of the wear pad and this would lead to wear on at least the upper stretch of the track, which is undesirable. The present invention overcomes the abovementioned disadvantage, amongst others, by providing a carrier track system which includes a carrier track bridge connected on and movable with intermediate relatively movable section means and extending in spaced relation substantially the entire length of said intermediate relatively movable section means, first support means on said carrier track bridge engaging and supporting said upper stretch substantially along its entire length in all adjusted positions of the flexible carrier track with said extensible and retractable structure, and second support means connected on one section of the pair of relatively movable sections of said structure, engaging and supporting said bottom stretch substantially along its entire length in all adjusted positions of the flexible carrier track with said extensible and retractable structure. Referring to the above, the present invention can be summarised in a single power track system reaching from the forward tip of the fly section of a multisection telescoping boom to the base section of the boom in which all portions of the flexible carrier track are adequately supported at all times during the extension and retraction of the boom in an efficient, compact and economical manner. A stiff leg attached at its forward end to the leading end of the boom fly section extends rearwardly and engages a guiding and restraining device on the forward end of a carrier track bridge, attached at its forward end to the leading end of the boom mid-section and extending rearwardly thereof. The bridge, in turn, engages a guiding and restraining device on the forward end of the boom base section and carries at its rear end a guide roller assembly which engages a bight portion of the flexible carrier track which has its forward end connected to the rear end of the stiff leg and its rear end connected to the restraining and guiding device for the bridge on the forward end of the boom base section. Spaced support rollers on the top of the bridge engage and support the stiff leg and the top stretch of the flexible carrier track in all adjusted positions of the latter. The bottom stretch of the flexible carrier track is also firmly supported in all adjusted positions by spaced support elements along the bottom of the boom base section. The rear end of the bridge is supported on the lower stretch of the flexible carrier track through its attached rear end guide roller assembly. Other features and advantages of the present invention will become apparent to those skilled in the art during the course of the following detailed description. Brief Description of the Drawings - Figure 1 is a side elevation of a multi-section telescoping boom equipped with a carrier track system in accordance with the present invention, the boom being fully retracted, and the drawing figure consisting of two portions which are joined longitudinally on the match line X-X. Figure 2 is an enlarged transverse vertical section taken on line 2-2 of Figure 1. Figure 3 is a similar section taken on line 3-3 of Figure 1. Figure 4 is a similar section taken on line 4-4 of Figure 1. Figure 4A is a fragmentary vertical section taken on line 4A-4A of Figure 4. Figure 5 is an enlarged transverse vertical section taken on line 5-5 of Figure 1. Figure 5A is a fragmentary side elevation taken on line 5A-5A of Figure 5. Figure 6 is an enlarged fragmentary end elevation taken on line 6-6 of Figure 1. Figure 7 is a side elevation of the boom and carrier track system with the boom fully extended and showing the vehicular support for the boom, the drawing figure being in three portions which are connected longitudinally on the match lines Y-Y and Z-Z. Figure 8 is a side elevation on a reduced scale of a multi-section telescoping boom machine according to the present invention showing approximately the correct dimensional proportions of the machine components, the machine boom being depicted in several longitudinally and angularly adjusted positions. Detailed Description - Referring to the drawings in detail wherein like numerals designate like parts, a self-propelled aerial work platform is illustrated in the drawings and it should be understood that the present invention is not limited in its application to this particular type of machine and may be employed on other forms of multi-section telescoping boom machines. The machine comprises a self-propelled steerable vehicular base 10 having a turntable 11 on which is mounted a horizontally turnable body portion 12 carrying a pivot 13 for a boom base section 14 which is raised and lowered by a luffing cylinder 15. The boom of the machine further comprises a boom mid-section 16 and a boom fly section 17, the three boom sections having telescoping guided engagement in a conventioanl manner. A worker platform 18 is carried by the leading end of the boom fly section 17 and is equipped with conventional means 19 operable to maintain the worker platform 18 in all adjusted positions of the telescoping boom. The movement and steering of the vehicular base 10, the luffing and sluing of the boom and the extension and retraction of the boom are all conventional and controlled by the worker on the platform 18, which platform is equipped with conventional controls forming no part of the present invention. In the particular machine illustrated in the drawings, the boom mid-section and fly section 17 are simultaneously extended and retracted relative to the base section 14 and relative to each other by, for example, but not limited to, hydraulic piston-cylinder assembly 8, 9 and other conventional means not shown, but kown in the art, and being unnecessary to describe for a full understanding of the invention. The three telescoping boom sections, therefore, have equal relative movements longitudinally during extension and retraction of the boom by the piston-cylinder assembly and other related means, and are not operated sequentially as occurs in many machines. Referring to Figure 8 which reflects approximately the true proportions of the machine, typically the fully extended three section telescoping boom may have a length of about one hundred and five feet. The boom sections 14, 16 and 17 typically measure thirty-eight feet each and the fully retracted length of the boom is therefore about forty feet. These dimensions are approximate and are provided for example only, and may be much greater in other machines. Continuing to refer to the drawings in greater detail, a rigid leg 20 preferably in the form of a rectangular tube has its forward end equipped with a fixed base plate 21 attached by bolts 22 to an opposing mounting plate 23 fixed to the top and outer end of a lateral support arm 24 projecting outwardly from one side of the boom fly section 17, Figure 6. As shown in Figure 6, the tubular leg 20 receives therethrough the various hoses and electrical cables essential to the operation of the machine, and prevents undesirable twisting, entangling or kinking of the hoses and cables. The rigid leg 20 extends cantilever-fashion along the full length of the boom fly section 17 and is guidingly and supportingly engaged with a device 25, Figure 5, fixed to the forward end of the boom mid-section 16. This device comprises a U-bracket 26 carrying within it a pair of vertical axis opposite side guide rollers 27 for the rigid leg 20 and a top horizontal axis retention roller 28 for the leg 20 so that the latter cannot rise out of engagement with the device 25. The forward end of a flexible carrier track bridge 29, preferably of I-beam form, and forming a very important component of the present invention, is attached by bolt means 30 to the bottom of the U-bracket 26 and is also attached at its bottom by bolt means 31 to a laterally extending rigid support arm 32, Figure 5, projecting outwardly from the adjacent side wall of the boom mid-section l6. The device 25 also includes within the bracket 26 a wear pad 33 for the bottom face of the rigid leg 20 during longitudinal guided movement of the latter with the boom fly section 17 relative to the mid-section 16. The carrier track bridge 29 extends cantilever-fashion from the forward end of the boom mid-section 16 along the length of the mid-section when the boom is fully extended as shown in Figure 7. At its rearward end, the bridge 29 has fixed thereto a guide and support roller assembly 34 including upper and lower parallel axis rollers 35 and 36 which engage the interior of a rolling bight portion 37 of a length of flexible carrier track 38 preferably of the type disclosed in U.S. Patent 4,129,277 to Tenniswood or an equivalent type of flexible carrier track. As shown in Figures 1, 2 and 7, an end link 39 of the carrier track 38 is attached by bolt means 40 to a bracket 41 fixed to the rear end of the rigid leg 20. The other end of the flexible carrier track 38 has an end link 42 thereof attached by bolts 43 to a rigid support arm 44 projecting laterally from the adjacent side wall of the boom base section 14, Figure 4. Also fixed on the support arm 44 rigidly is an inverted U-mounting bracket 45, bridging the end link 42 and supporting on its top a pair of guide and retention rollers 46 for the movable bridge 29. Also fixed to the top of the bracket 45 as by bolt means 47 is a wear pad 48 for the bottom face of the bridge 29. It can now be noted that in accordance with a very unique feature of the invention the rear end of the bridge 29 is supported on the lower stretch 49 of the flexible carrier track 38 through the lower roller 36, while the top stretch 50 of the flexible carrier track is engaged supportively with the upper roller 35 of the dual roller assembly 34 on the rear of the bridge 29. Moreover, the entire bottom stretch 49 of the carrier track is supported along its length when the boom is fully retracted, Figure 1, by a series of support plates 51 projecting laterally outwardly from one side of the boom base section 14 and being attached to the bottom wall of the boom base section as shown in Figures 2 and 3. Similarly, means are provided to support the top stretch 50 of the flexible carrier track 38 along its entire length where the multi-section boom is extended, Figure 7. This means comprises a series of spaced transverse axis support roller 52 held by brackets 53, fixed on the bridge 29, as shown. The support rollers 52 are adapted to engage and support the upper stretch 50 of the flexible carrier track as the boom becomes extended and to engage and support the stiff leg 20, Figure 1, as the boom is retracted. In Figure 3, the stiff leg 20 is shown riding on the support rollers 52, and the upper stretch 50 of the carrier track is shown in phantom lines only, Figure 3, in the position it assumes above the rollers 52 as the boom is extended, Figure 7. Thus, regardless of the relative lengths of the top and bottom stretches 50 and 49 of the flexible carrier track 38, both stretches are fully supported at all times. Moreover, the rear end roller assembly 34 of the bridge 29 is always in engagement with the rolling bight portion 37 of the flexible carrier track, as explained previously, and the bottom stretch 49 of the carrier track is always supporting the rear end of the moving bridge 29. The same hoses and cables received by the tubular rigid leg 20 are also received in the flexible carrier track 38, as indicated in Figures 2 and 3. As the multi-section boom extends or retracts by operation of the piston-cylinder assembly 8, 9 and related means in the previously-described manner, the moving bridge 29 connected with the forward end of the boom mid-section 16 is always adjusted forwardly or rearwardly to lend support to the upper stretch 50 of the flexible carrier track and/or to the rigid leg 20. It is believed that the construction and operation of the carrier track 38 during extension and retraction of the boom has now been made clear. During extension and retraction of the boom, the rigid leg 20 is always engaged with the device 25 on top of the bridge 29 at the forward end of the latter. The side rollers 27 of this device guide the leg 20 in its forward and rear movement while the wear pad 33 supports the leg. During transport of the machine on its self-propelled base 10, the rollers 27 stabilize the leg 20 laterally, and the upper transverse roller 28 limits upward movement of the leg 20 during transport. The leg is restrained and guided in all directions. Similarly, the movable bridge 29 is always engaged at its bottom with the wear pad 48, Figure 4, and the two guide and restraining rollers 46 fixed on the forward end of the boom base section 14 by the bracket 45. The recessed wear pad 48 imparts lateral stability to the bridge 29 and the two rollers 46 which straddle the center longitudinal web of the I-beam bridge restrict vertical displacement of the bridge during transport. All relatively movable components of the system are therefore positively guided during their movements and restrained against lateral and vertical displacement. The terms and expressions which have been employed herein are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof but it is recognized that various modifications are possible within the scope of the invention claimed.

Claims: A carrier track system for a multi-section extensible and retractable structure having at least a pair of relatively movable sections (17, 14) separated by intermediate relatively movable section means (16), comprising, a single length of flexible carrier track (38) having its opposite ends (39, 42) connected between the pair of relatively movable sections (17, 14) of the extensible and retractable structure and spanning said intermediate relatively movable section means (16) of the extensible and retractable structure, said flexible carrier track having a rolling bight portion (37) and an upper stretch (50) spaced from a bottom stretch (49), which stretches vary in their lengths in response to extension and retraction of said structure, a carrier track bridge (29) connected on and movable with the intermediate relatively movable section means (16) and extending in spaced relation substantially the entire length of said intermediate relatively movable section means (16), first support means (52) on said carrier track bridge (29) engaging and supporting said upper stretch (50) substantially along its entire length in all adjusted positions of the flexible carrier track (38) with said extensible and retractable structure, and second support means (51) connected on one section (14) of the pair of relatively movable sections (17, 14) of said structure, engaging and supporting said bottom stretch (49) substantially along its entire length in all adjusted positions of the flexible carrier track (38) with said extensible and retractable structure. A carrier track system for a multi-section extensible and retractable structure as set forth in claim 1, in which said extensible and retractable structure is a multi-section telescoping boom, said at least a pair of relatively movable sections (17, 14) comprise a boom fly section (17) and a boom base section (14), and said intermediate relatively movable section means (16) comprises a boom mid-section (16), said carrier track bridge (29) having its forward end fixedly connected to said boom mid-section (16) near the forward end of the mid-section and extending rearwardly along the mid-section (16), a rigid leg (20) having its forward end attached to the boom fly section (17) near the forward end of the fly section and extending rearwardly along the fly section (17), the upper stretch (50) of said flexible carrier track (38) having a forward end (39) attached to the rear end of said rigid leg (20), the bottom stretch (49) of said flexible carrier track (38) having a rear end (42) attached to the boom base section (14) near the forward end of the base section, and supporting means (34) for the rear end of the bridge member (29) on the bridge member (29) and engaging the interiors of said bottom stretch (49) and said upper stretch (50). A carrier track system as defined in claim 2, including a device (25) on the boom mid-section (16) near its forward end guidingly supporting said rigid leg (20) during forward and rear movements of the latter (20). A carrier track system as defined in claim 2, including a device (45, 46) on the boom base section (14) guidingly engaging and supporting said bridge (29) during forward and rear movements of the latter (29). A carrier track system as defined in claim 2, and said rigid leg (20), carrier track bridge (29) and single flexible carrier track (38) being disposed exteriorly of the multi-section boom, and fixed lateral support arms (24, 32, 44) on the boom fly section (17), and on the boom mid-section (16) and base section (14) supporting said rigid leg (20), said bridge (29) and the rear end (42) of the flexible carrier track (38), respectively. A carrier track system as defined in claim 3, and said device (25) on the boom mid-section (16) being fixed on said carrier track bridge (29). A carrier track system as defined in claim 6 and the device (25) including a pair of opposite side guide rollers (27) for said rigid leg (20), a top restraining roller (28) for the rigid leg (20), and a wear pad (33) engageable with the bottom face of the rigid leg (20). A carrier track system as defined in claim 4, and the device (45, 46) on the boom base section (14) including a wear pad (48) engageable with the bottom face of said bridge (29), and guide and restraint roller means (46) for the bridge (29) disposed above a longitudinal wall of the bridge (29). A carrier track system as defined in claim 8, and the carrier track bridge (29) having substantially an I-beam cross section and said guide and restraint roller means (46) for the bridge (29) being disposed above a bottom longitudinal web of the bridge (29) and on opposite sides of a centre longitudinal web of the bridge (29). A carrier track system as defined in claim 2, and said second support means (51) comprising longitudinally spaced support plate elements (51) fixed to the bottom of the boom base section (14) and projecting laterally of one side wall thereof. A carrier track system as defined in claim 2, in which said supporting means (34) comprises a dual guide roller assembly (34, 35, 36) on the bridge (29) engaged with said bight portion (37). A carrier track system as defined in claim 2, in which said supporting means (34) on the rear end of said bridge (29) engages the interior of said rolling bight portion (37). A carrier track system as defined in claim 2, and support and guidance means (25, 45-46) for the rigid leg (20) on the bridge (29) and for the bridge (29) on the boom base section (14). A carrier track system as defined in claim 2, and said second support means (51) for the bottom stretch (49) of said flexible carrier track (38) comprising a series of longitudinally spaced support plates on the boom base section (14), and the first support means (52) for said upper stretch (50) comprising a series of support rollers (52) on and projecting above the top face of said bridge (29). A carrier track system as defined in claim 2, and said rigid leg (20) and bridge (29) being disposed laterally outwardly of one side of the telescoping boom sections with the rigid leg (20) disposed above the bridge (29) in parallel relationship thereto, and the single flexible carrier track (38) being disposed in and operating in a vertical plane common to the rigid leg (20) and bridge member (29). A carrier track system as defined in claim 15, and lateral support arms (24, 32) on corresponding sides of the boom fly (17) and mid (16) sections for said rigid leg (20) and bridge (29), respectively. A carrier track system as defined in claim 16, and a lateral support arm (44) on the boom base section (14) for the rear end (42) of said flexible carrier track (38), and guiding and supporting means (45, 46) for said bridge (29) on the last-named lateral support arm (44). A carrier track system as defined in claim 16, and guiding and supporting means (25) for said rigid leg (20) on said bridge (29) adjacent the forward end of said bridge (29). A carrier track system as defined in claim 2, and said supporting means (34) for the rear end of the bridge member (29) comprising a dual roller assembly (35, 36) on the rear end of the bridge member (29) including upper (35) and lower (36) rollers disposed in a common vertical plane with the rigid leg (20), bridge (29) and flexible carrier track (38), and the lower roller (36) of the dual roller assembly (35, 36) rolling on and being supported by the bottom stretch (49) of the flexible carrier track (38) ahead of said rolling bight portion (37). A carrier track system as set forth in claim 2, in which said supporting means (34) comprises a roller assembly (34, 35, 36) engaged with and between the upper stretch (50) and the bottom stretch (49). A carrier track system as set forth in claim 2, in which the rear end of the bridge member (29) is supported by said supporting means (34) supported by said bottom stretch (49) of said carrier track forwardly of said bight portion (37). A carrier track system as set forth in claim 2, in which said supporting means (34) engages the interiors of said bottom stretch (49) and said upper stretch (50) at said rolling bight portion (37). A carrier track system as set forth in claim 2, in which said bridge (29) is disposed at an elevation below said rigid leg (20). A carrier track system as set forth in claim 2, in which said flexible carrier track (38) is disposed in a vertical plane common to said rigid leg (20) and said bridge (29). A carrier track system as set forth in claim 2, in which said first support means (52) on said carrier track bridge comprises a plurality of longitudinally spaced support members (52) on the top of said bridge (29) engaging and supporting said rigid leg (20) and said upper stretch (50) of said flexible carrier track (38) forwardly of said bight portion (37). A carrier track system as set forth in claim 25, in which said plurality of longitudinally spaced support members (52) comprise a plurality of support rollers (52) extending above the top surface of said bridge (29).

Inventors: SPIDEL, JEFFREY LYNN
Applicants: KIDDE INDUSTRIES INC.
Application year: 1987
Main classification: B66F9
IPC codes: B66C23, B66F11, B66C7