WO2018165587A1 - Mât de chariot élévateur ayant des tubes comme éléments structuraux et/ou hydrauliques - Google Patents

Mât de chariot élévateur ayant des tubes comme éléments structuraux et/ou hydrauliques Download PDF

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Publication number
WO2018165587A1
WO2018165587A1 PCT/US2018/021810 US2018021810W WO2018165587A1 WO 2018165587 A1 WO2018165587 A1 WO 2018165587A1 US 2018021810 W US2018021810 W US 2018021810W WO 2018165587 A1 WO2018165587 A1 WO 2018165587A1
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WO
WIPO (PCT)
Prior art keywords
tubes
tube
section
mast
brace
Prior art date
Application number
PCT/US2018/021810
Other languages
English (en)
Inventor
Barry Warner
Original Assignee
Hyster-Yale Group, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hyster-Yale Group, Inc. filed Critical Hyster-Yale Group, Inc.
Priority to DE212018000179.0U priority Critical patent/DE212018000179U1/de
Priority to CN201890000599.0U priority patent/CN211110874U/zh
Publication of WO2018165587A1 publication Critical patent/WO2018165587A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
    • B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
    • B66F9/075—Constructional features or details
    • B66F9/08—Masts; Guides; Chains

Definitions

  • This disclosure relates generally to lift trucks and more particularly to lifting structures for lift trucks.
  • Masts are commonly used on lift trucks to provide a mechanical system for raising and lowering attachments, such as forks, paper roll clamps, etc., and attendant loads.
  • Currently available masts provide a support structure for lift components such as lift chains, pulleys, and hydraulic hoses to accomplish relative movement between mast sections.
  • a mast comprises one or more mast sections, one of which is affixed to a lift truck frame, preferably in a tiltable manner, another section, if included, that slidingly engages the first section, and if included, other sections that slidingly engage the previous section.
  • a combination of hydraulic components and lift chains is typically used to move an attachment affixed to such a mast, and to move mast sections with respect to each other.
  • Tubular elements are used to construct the support structure for a mast for a lift truck. Hydraulic cylinders may be integrated within the tubular elements. Braces may be included to alter one or more of stiffness, torsional resistance, and bending resistance for such a mast.
  • Fig. 1 is a right side isometric view of an example mast in a raised position
  • Fig. 2 is a front right isometric view of a first section of the mast of Fig. 1.
  • Fig. 3 is a front right isometric view of a second section of the mast of Fig. 1.
  • Fig. 4 is a cross-sectional view of the mast of Fig. 1 in a lowered position taken at
  • Fig. 5 is a cross-sectional view of the mast of Fig. 1 in a lowered position taken at
  • FIG. 6 is a cross-sectional view of an example sealing arrangement for a hydraulic cylinder.
  • Fig. 7 is a front right isometric view of a third section of the mast of Fig. 1.
  • Fig. 8 is a front left isometric view of another example mast section, according to another embodiment.
  • Fig. 9 is a cross sectional view of the mast of Fig. 1 in a lowered position taken at
  • Fig. 10 is an enlarged view of another portion of the mast of Fig. 1.
  • Fig. 11 is an enlarged view of a portion of the mast of Fig. 1.
  • Fig. 12 is a front view of the mast of Fig. 1 in a lowered position, with the
  • FIG. 13 is a schematic view of an example mast attached to a lift truck.
  • Fig. 14 is a rear view of the mast of Fig. 12 in a lowered position.
  • Fig. 15 is a right side view of the mast of Fig. 12 in a lowered position.
  • Fig. 16 is a schematic view of one half of a hydraulic circuit for a mast, with the other half being symmetric to the illustrated half.
  • Fig. 17 is a left, rear isometric view of another example mast with an outer stage and an inter stage at a fully raised position.
  • Fig. 18 is a left, rear isometric view of the mast of Fig. 17 in a in a lowered
  • Fig. 19 is a left, rear isometric view of the mast of Fig. 17 with a fork carriage at the top of a free-lift position and the lift chains removed for clarity.
  • Fig. 20 is a left, rear isometric view of the mast of Fig. 17 with an outer stage at a fully raised position and the lift chains removed for clarity.
  • Fig. 21 is a top view of the mast of Fig. 17.
  • Fig. 22 is a cross-sectional view of the mast of Fig. 17 taken along line 22-22 of Fig. 18.
  • Fig. 23 is a left, rear isometric view of the mast of Fig. 17 with a fork carriage and free-lift cylinders removed.
  • Fig. 24 is an enlarged, left-side partially cut-away view of the mast of Fig. 23.
  • Fig. 25 is another enlarged, left-side partially cut-away view of the mast of Fig. 23.
  • Fig. 26 is a right front isometric view of another example mast section, according to another embodiment.
  • Fig. 27 is a left side isometric view of an example mast in a lowered position, according to another embodiment.
  • Fig. 28 is a front view of the mast of Fig. 27.
  • Fig. 29 is a left side isometric view of the mast of Fig 27 in a raised position.
  • Fig. 30 is a top view of the mast of Fig. 27.
  • construction materials and techniques is that they commonly use specially shaped metal channels that are relatively expensive to manufacture, for example, via hot-rolling or welding; are relatively difficult to manufacture with consistent tolerances; and are relatively heavy.
  • the present inventor has also recognized another drawback of typical mast constructions is that they expose hydraulic hoses such that mechanical abrasion, pinching, and ultraviolet radiation may contribute to degrading such hoses, thus potentially creating leak points, decreasing hose life, and increasing maintenance and replacement costs.
  • drawn tubular stock may address such drawbacks of typical masts because it has less mass per unit length than hot-rolled or welded channel, and costs less than hot-rolled or welded channel per ton.
  • drawn tubular stock include tubes made from steel or other suitable material having a cylindrical, oval, or square cross-section, or any other suitable hollow shape that is readily available or could be created.
  • tubular materials for mast construction optionally allows hydraulic cylinders to be integrated within such tubular materials, which may reduce or eliminate hydraulic hose exposure, reduce or eliminate hydraulic hoses, and include fewer items within or near a viewing window created by the upright portions of a mast constructed of such tubular materials when compared to typical masts.
  • a mast comprises three stages, or sections, which may be referred to as a first, second, and third stage or section, or an outer, intermediate, and inner stage or section.
  • a first, second, and third stage or section or an outer, intermediate, and inner stage or section.
  • Mast 5 comprises a first section 10, a second section 15, and a third section 20.
  • Other embodiments may have one, two, or four or more stages or sections.
  • First section 10 may be considered an outer stage and comprises a first tube set 25 and a second tube set 30.
  • an optional first end brace 35 is secured proximate a first end of the tubes 40 and 45 of the first tube set 25 and proximate a first end of the tubes 50 and 55 of the second tube set 30.
  • First end brace 35 may be secured to the first tube set 25 and to the second tube set 30 via an adhesive, an interference fit, welding, or other suitable securing manner.
  • securing the first end brace 35 to the first tube set 25 and to the second tube set 30 does not breach any of the walls of tubes 40, 45, 50, or 55.
  • An optional second end brace 60 is secured proximate a second end of the first tube set 25 and proximate a second end of the second tube set 30 in the same manner as the first end brace 35.
  • tubes 40, 45, 50, and 55 have the same length, the same outer
  • tubes 40 and 50 may have the same length, the same outer diameter, the same inner diameter, and the same wall thickness
  • tubes 45 and 55 may have the same length, the same outer diameter, the same inner diameter, and the same wall thickness, any one or more of which may be different from the length, the outer diameter, the inner diameter, and the wall thickness of tubes 40 and 50.
  • tubes 40, 45, 50, and 55 have a length of 3 meters (“m"), an outer diameter of 45 millimeters ("mm"), an inner diameter of 33 mm, a wall thickness of 6 mm and are made of commercially available steel tubing, such as cold drawn seamless steel tubes made to meet the specifications of European Standard EN 10305-1, ATSM A512, or an equivalent.
  • none of the tubes 40, 45, 50, and 55 share a common longitudinal axis.
  • First end brace 35 and second end brace 60 are each configured to retain the first and second ends, respectively, of the first tube set 25 and the second tube set 30 in place, that is, to prevent or hinder tubes 40, 45, 50, and 55 from moving with respect to one another.
  • first end brace 35 and second end brace 60 are made from stamped, cast, or machined metal, such as steel or aluminum.
  • first end brace is 40 mm thick and second end brace 60 is 80 mm thick.
  • An optional intermediate brace 65 is secured to one tube of the first tube set 25, for example, to tube 40, and to one tube of the second tube set 30, for example, to tube 50.
  • intermediate brace 65 may be secured to multiple tubes of the first tube set 25 and to multiple tubes of the second tube set 30.
  • Intermediate brace 65 is secured to the first tube set 20 and to the second tube set 30, for example, using one of the manners described with respect to the first end brace 35.
  • Intermediate brace 65 is located between the first end of the first and second tube sets 25, 30 and the second end of the first and second tube sets 25, 30.
  • additional intermediate braces, such as intermediate brace 65 may be secured to the first tube set 25 and to the second tube set 30.
  • intermediate brace 65 increases stiffness and resistance to bending for the first section 10.
  • intermediate brace 65 is made from stamped, cast, or machined metal, such as steel or aluminum and has a thickness of 80 mm.
  • one or more side braces 70 are secured to the tubes of the first tube set 25 or to the tubes of the second tube set 30, but a side brace 70 is not secured to tubes of both the first tube set 25 and the second tube set 30.
  • Side braces 70 are located between the first end of the first and second tube sets 25, 30 and the second end of the first and second tube sets 25, 30.
  • Side braces 70 are secured to the tubes of the first tube set 25 or to the tubes of the second tube set 30, for example, using one of the manners described with respect to the first end brace 35.
  • side braces 70 increase stiffness and resistance to bending for the first section 10.
  • side braces 70 are made from stamped, cast, or machined metal, such as steel or aluminum and have a thickness of 50 mm.
  • braces 35, 60, intermediate braces 65, side braces 70, or other suitable brace(s) is a design consideration that depends on factors such as intended loads and use of the mast 5, the length of the tubes of the first tube set 25 and the second tube set 30, and the other physical dimensions and materials of the tubes of the first tube set 25 and the second tube set 30.
  • second section 15 comprises a third tube set 75 and a fourth tube set 80.
  • An optional third end brace 85 is secured proximate a first end of the tubes 90 and 95 of the third tube set 75 and proximate a first end of the tubes 100 and 105 of the fourth tube set 80.
  • Third end brace 85 is secured, for example, using one of the manners described with respect to the first end brace 35.
  • securing the third end brace 85 to the third tube set 75 and the fourth tube set 80 does not breach any of the walls of tubes 90, 95, 100, or 105.
  • An optional fourth end brace 110 is secured proximate a second end of the third tube set 75 and proximate a second end of the second tube set 80, for example, using one of the manners described with respect to the first end brace 35.
  • the fourth end brace 110 is secured to the second end of tubes 90, 95, 115, and 120 of the third tube set 75 and to the second end of tubes 100, 105, 125, and 130 of the fourth tube set 80.
  • a hydraulic circuit may be formed among the fourth end brace 110 and the tubes 115 and 125, for example, as described below with respect to Figs. 23-25.
  • an optional hydraulic circuit may be formed using tubes 115 and 125, or other suitable tubes, and associated hoses, tubes, or other suitable hydraulic fittings.
  • fewer tubes may be used for the third and fourth tube sets, for example, by eliminating tubes 120 and 130.
  • tubes 90, 95, 100, and 105 have the same length, the same outer diameter, the same inner diameter, the same wall thickness, and are made from the same material.
  • tubes 90 and 100 may have the same length, the same outer diameter, the same inner diameter, and the same wall thickness
  • tubes 95 and 105 may have the same length, the same outer diameter, the same inner diameter, and the same wall thickness, any one or more of which may be different from the length, the outer diameter, the inner diameter, and the wall thickness of tubes 90 and 100.
  • tubes 90, 95, 100, and 105 have a length of 3 m, an outer diameter of 45 mm, an inner diameter of 33 mm, a wall thickness of 6 mm and are made of
  • tubes 115, 120, 125, and 130 have the same length, the same outer diameter, the same inner diameter, the same wall thickness, and are made from the same material.
  • tubes 115 and 125 may have the same length, the same outer diameter, the same inner diameter, and the same wall thickness and tubes 120 and 130 may have the same length, the same outer diameter, the same inner diameter, and the same wall thickness, any one or more of which may be different from the length, the outer diameter, the inner diameter, and the wall thickness of tubes 115 and 125.
  • tubes 115, 120, 125, and 130 have a length of 3 m, an outer diameter of 25 mm, an inner diameter of 13 mm, a wall thickness of 6 mm and are made of
  • chromed steel tubing manufactured, for example, from European Standard EN 10305-1, ATSM A512, or equivalent cold drawn seamless steel tubes.
  • Optional third end brace 85 is configured to retain the first ends of at least one tube of the third tube set 75 and of at least one tube of the fourth tube set 80 in place, for example, to prevent or hinder tubes 90, 95, 100, and 105 from moving with respect to one another.
  • an optional third end brace, such as third end brace 85 may be connected only to tubes 90 and 100.
  • An optional fourth end brace 110 is configured to retain the second ends of two or more tubes of the third tube set 75 and of the fourth tube set 80 in place, for example, to prevent or hinder tubes 90, 95, 115, 120, 100, 105, 125 and 130 from moving with respect to one another.
  • third end brace 85 and fourth end brace 110 are made from stamped, cast, or machined metal, such as steel or aluminum.
  • third end brace 85 is 40 mm thick and fourth end brace 110 is 80 mm thick.
  • An optional intermediate brace 135 is secured to at least one of the tubes of the third tube set 75, for example to tube 90, 95, or both, and to at least one of the tubes of the fourth tube set 80, for example to tube 100, 105, or both.
  • Intermediate brace 135 is secured to the third tube set 75 and to the fourth tube set 80, for example, using one of the manners described with respect to the first end brace 35.
  • Intermediate brace 135 is located between the first end of the third and fourth tube sets 75, 80 and the second end of the third and fourth tube sets 75, 80.
  • additional intermediate braces such as intermediate brace 135, may be secured to the third tube set 75 and to the fourth tube set 80.
  • intermediate brace 135 increases stiffness and resistance to bending for the second section 15.
  • intermediate brace 135 is made from stamped, cast, or machined metal, such as steel or aluminum and is 50 mm thick.
  • one or more side braces 140 are secured to at least two of the tubes of the third tube set 75 or to at least two of the tubes of the fourth tube set 80, but a side brace 140 is not secured to tubes of both the third tube set 75 and the fourth tube set 80.
  • Side braces 140 are located between the first end and the second end of the third tube set 75 and between the first end and the second end of the fourth tube set 80.
  • Side braces 140 are secured to the tubes of the third tube set 75 or to the tubes of the fourth tube set 80, for example, using one of the manners described with respect to the first end brace 35.
  • side braces 140 increase stiffness and resistance to bending for the second section 15.
  • side braces 140 are made from stamped, cast, or machined metal, such as steel or aluminum and are 50 mm thick.
  • Optional guides 145 and 150 are attached to the third tube set 75. As best
  • guide 145 interacts with tube 45 of the first section 10 and guide 150 interacts with tube 40 of the first section 10 to provide one or more of alignment, stability, and spacing between the first section 10 and the second section 15 when the second section 15 moves with respect to the first section 10.
  • Guide 145 may be attached to a side brace 147 and guide 150 may be attached to the third end brace 85.
  • guides 145 and 150 are rollers, however such guides may comprise ball bearing sets, pads of low-friction material, or other suitable arrangements.
  • Optional guides 155 and 160 are attached to the fourth tube set 80.
  • Guide 155 interacts with tube 55 of first section 10 and guide 160 interacts with tube 50 of first section 10 to provide one or more of alignment, stability, and spacing between the first section 10 and the second section 15 when the second section 15 moves with respect to the first section 10.
  • Guide 155 may be attached to a side brace 147 and guide 160 may be attached to the third end brace 85.
  • guides 155 and 160 are rollers, however such guides may comprise ball bearing sets, pads of low-friction material, or other suitable arrangements.
  • tube 115 is sized and dimensioned to fit within tube 40 of first section 10 such that tubes 115 and 40 share a common longitudinal axis
  • tube 120 is sized and dimensioned to fit within tube 45 of first section 10 such that tubes 120 and 45 share a common longitudinal axis
  • tube 125 is sized and dimensioned to fit within tube 50 of first section 10 such that tubes 125 and 50 share a common longitudinal axis
  • tube 130 is sized and dimensioned to fit within tube 55 of first section 10 such that tubes 130 and 55 share a common longitudinal axis.
  • seals are included such that the combination of tubes 115 and 40 forms a hydraulic cylinder, and of tubes 125 and 50 forms a hydraulic cylinder.
  • FIG. 6 an optional, example sealing arrangement to form a hydraulic cylinder from tubes 125 and 50 is described. Such a sealing arrangement may be used to form all hydraulic cylinders for mast 5, or other suitable sealing arrangements may be used.
  • a cartridge C is inserted into the top end of tube 50 to close off tube 50 and provides a sealing and guiding arrangement for tube 125.
  • Cartridge C comprises a head portion H that extends beyond the end of tube 50 and an insert portion I that extends into tube 50.
  • a groove Gl formed between the head portion H and the insert portion I is shaped to receive a lip L formed at the end of tube 50.
  • a threaded section ending at SR formed in the insert portion I is shaped to fit into a groove G2 formed in tube 50.
  • the end of tube 50 may be machined to form the groove G2 and the lip L.
  • the threaded section extends between SR and Gl and is used to mechanically connect the cartridge C to the tube 50.
  • Other suitable connecting mechanisms may be used in alternate embodiments.
  • the insert portion I also bears seals SI in a groove G3 to inhibit hydraulic fluid from leaking between tube 50 and the inner portion I.
  • Seals SI may comprise multiple sealing elements, such as o-rings Ol and 02, where Ol serves as a back-up seal for 02, or a single sealing element. In other embodiments, additional grooves and sealing elements are provided to seal between the inner portion I and the tube 50.
  • the head portion H includes a seal S2 in a groove G4 and another seal S3 in a groove G5. In other embodiments, only one seal is included in the head portion H, while other embodiments include more than two seals. Seals in the head portion H inhibit hydraulic fluid from leaking between the cartridge C and tube 125.
  • Cartridge C also includes a bearing Bl in a groove G6 and a bearing B2 in a groove G7. Bearings Bl and B2 facilitate a sliding movement between tube 125 and cartridge C and also facilitate holding tube 125 to linear movement along axis A.
  • the combination of tubes 120 and 45 and of tubes 130 and 55 create guiding structures to facilitate maintaining alignment between the first section 10 and the second section 15 when the second section 15 moves with respect to the first section 10.
  • the combination of tubes 120 and 45 may include seals to form a hydraulic cylinder
  • the combination of tubes 130 and 55 may include seals to form a hydraulic cylinder.
  • third section 20 comprises a fifth tube set 165 and a sixth tube set 170.
  • An optional fifth end brace 175 is secured proximate a second end of the fifth tube set 165 and proximate a second end of the sixth tube set 170, for example, using one of the manners described with respect to the first end brace 35.
  • the fifth end brace 175 is secured to the second end of one or more of tubes 180, 185, and 190 of the fifth tube set 165 and to the second end of one or more of tubes 195, 200, and 205 of the sixth tube set 170.
  • Fifth end brace 175 is configured to retain the second ends of one or more tubes of the fifth tube set 165 and of one or more tubes of the sixth tube set 170 in place, that is, to prevent or hinder two or more of tubes 180, 185, 190, 195, 200, and 205 from moving with respect to one another.
  • fifth end brace 175 is made from stamped, cast, or machined metal, such as steel or aluminum.
  • fifth end brace 175 is 60 mm thick.
  • a hydraulic circuit may be formed among the fifth end brace 175 and the tubes 180 and 190, for example, in a manner similar to that described below with respect to Figs. 23-25.
  • an optional hydraulic circuit may be formed using tubes 180 and 190, or other suitable tubes, and associated hoses, tubes, or other suitable hydraulic fittings.
  • tubes 180, 185, 195, and 200 have the same length, the same outer diameter, the same inner diameter, the same wall thickness, and are made from the same material.
  • tubes 180 and 195 may have the same length, the same outer diameter, the same inner diameter, and the same wall thickness
  • tubes 185 and 200 may have the same length, the same outer diameter, the same inner diameter, and the same wall thickness, any one or more of which may be different from the length, the outer diameter, the inner diameter, and the wall thickness of tubes 180 and 195.
  • tubes 180, 185, 195, and 200 have an outer diameter of 45 mm, an inner diameter of 33 mm, a wall thickness of 6 mm and are made of commercially available steel tubing, such as cold drawn seamless steel tubes made to meet the specifications of European Standard EN 10305-1, ATSM A512, or an equivalent.
  • none of tubes 180, 185, 190, and 200 share a common longitudinal axis.
  • tubes 190, and 205 have the same length, the same outer diameter, the same inner diameter, the same wall thickness, and are made from the same material.
  • tubes 190, and 205 have an outer diameter of 25 mm, an inner diameter of 15 mm, a wall thickness of 5 mm and are made of commercially available chromed steel tubing, manufactured, for example, from European Standard EN 10305-1, ATSM A512, or an equivalent.
  • An optional intermediate brace 210 is secured to one tube of the fifth tube set 165, for example to tube 180, and to one tube of the sixth tube set 170, for example to tube 195. Intermediate brace 210 is preferably located proximate to a first end of the tubes 180 and 195. In other embodiments, such an intermediate brace may be secured to more than one tube of the fifth tube set 165 and to more than one tube of the sixth tube set 170. Optionally, additional intermediate braces, such as intermediate brace 215, may be secured to the fifth tube set 165 and to the sixth tube set 170. Intermediate brace 215 is preferably secured to tubes 180 and 185 of the fifth tube set 165 and to tubes 195 and 200 of the sixth tube set 170.
  • such an intermediate brace is secured to only one tube of the fifth tube set 165 and to one tube of the sixth tube set 170.
  • Intermediate braces 210 and 215 are secured to the fifth tube set 165 and to the sixth tube set 170, for example, using one of the manners described with respect to the first end brace 35.
  • intermediate braces 210 and 215 increase stiffness and resistance to bending for the third section 20.
  • intermediate braces 210 and 215 are made from stamped, cast, or machined metal, such as steel or aluminum and are 50 mm thick.
  • one or more side braces 220 are secured to the tubes of the fifth tube set 165 or to the tubes of the sixth tube set 170, but a side brace 220 is not secured to tubes of both the fifth tube set 165 and the sixth tube set 170.
  • Side braces 220 are optionally located between a first end of the fifth and sixth tube sets 165, 170 and the second end of the fifth and sixth tube sets 165, 170.
  • Side braces 220 are secured to the tubes of the fifth tube set 165 or to the tubes of the sixth tube set 170, for example, using one of the manners described with respect to the first end brace 35.
  • side braces 220 increase stiffness and resistance to bending for the third section 20.
  • side braces 220 are made from stamped, cast, or machined metal, such as steel or aluminum and are 50 mm thick.
  • end brace 175, intermediate braces 210 and 215, and side braces 220 is a design consideration that depends on factors such as intended loads and use of the mast 5, the length of the tubes of the fifth tube set 165 and the sixth tube set 170, and the other physical dimensions and materials of the tubes of the fifth tube set 165 and the sixth tube set 170.
  • Optional guides 225 and 230 are attached to the fifth tube set 165. As best
  • guide 225 interacts with tube 95 of the second section 15 and guide 230 interacts with tube 90 of the second section 15 to provide one or more of alignment, stability, and spacing between the second section 15 and the third section 20 when the third section 20 moves with respect to the second section 15.
  • Guide 225 may be attached to a side brace 227 and guide 230 may be attached to a side brace 232.
  • guides 225 and 230 are rollers, however such guides may comprise ball bearing sets, pads of low-friction material, or other suitable arrangements.
  • Optional guides 235 and 240 are attached to the sixth tube set 170.
  • Guide 235 interacts with tube 105 of the second section 15 and guide 240 interacts with tube 100 of the second section 15 to provide one or more of alignment, stability, and spacing between the second section 15 and the third section 20 when the third section 20 moves with respect to the second section 15.
  • Guide 235 may be attached to a side brace 227 and guide 240 may be attached to a side brace 232.
  • guides 235 and 240 are rollers, however such guides may comprise ball bearing sets, pads of low- friction material, or other suitable arrangements.
  • more or fewer guides may be provided on third section 20 and on second section 15.
  • tube 190 is sized and dimensioned to fit within tube 90 of the second section 15 such that tubes 190 and 90 share a common longitudinal axis
  • tube 205 is sized and dimensioned to fit within tube 100 of the second section 15 such that tubes 205 and 100 share a common longitudinal axis.
  • seals are included such that the combination of tubes 190 and 90 forms a hydraulic cylinder, and of tubes 205 and 100 forms a hydraulic cylinder.
  • the seals may be the seals described above, or other suitable seals.
  • additional tubes may be included for the fifth tube set 165 and the sixth tube set 170 such that the additional tubes are sized and arranged to fit within tubes 95 and 105 of the third tube set 75 and the fourth tube set 80, respectively, of the second section 15.
  • Such additional tubes combined with tubes 95 and 105 may serve as guiding elements to provide one or more of alignment, stability, and spacing, or may include seals to form additional hydraulic cylinders.
  • the third section 20 optionally includes a free lift arrangement 245. While a specific embodiment of a free lift arrangement 245 is illustrated and described, other suitable free lift arrangements may be used.
  • Free lift arrangement 245 comprises two hydraulic cylinders 250, one attached proximate the fifth tube set 165 and the other attached proximate the sixth tube set 170. Both hydraulic cylinders 250 are optionally attached to the intermediate brace 215 and each of the hydraulic cylinders 250 is optionally attached to one of the side braces 232. Other suitable attachment arrangements may be used. Hydraulic cylinders 250 may be attached to the intermediate brace 215 and the side braces 232 via adhesive, welding, interference fit or other suitable attachment manner. Preferably, attaching the hydraulic cylinders 250 to the intermediate brace 215 and the side braces 232 does not breach a sidewall of the hydraulic cylinders 250.
  • Pulleys 255 are optionally arranged such that an axis through the center of
  • each pulley 255 i.e., a central axis 260
  • a central axis 260 is configured to be substantially aligned with a longitudinal axis 265 of a lift truck 270 (Fig. 13) when mast 5 is installed on lift truck 270.
  • the central axis 260 of each pulley 255 may be at any suitable angular orientation with respect to the longitudinal axis 265 of lift truck 270.
  • Lift chains 275 are secured at a first end 280 to a hydraulic cylinder 250, run over a pulley 255 and are secured at a second end 285 to a fork carriage 272 (Fig. 13), or other suitable attachment.
  • the third section 20 is nested in the second section 15, and the combination of the second section 15 and third section 20 is nested in the first section 10 (Figs. 12, 14, and 15) to form mast 5.
  • Mast 5 is attached to lift truck 270 such that mast 5 may be tilted, for example, by using hydraulic cylinders 274, or may be rigidly attached to lift truck 270.
  • a hydraulic circuit 290 (Fig. 16) communicates from hydraulics of lift truck 270 to and through the mast 5.
  • Hydraulic hoses 295 fluidly connect the hydraulic circuit 290 of mast 5 with hydraulics of lift truck 270 and communicate hydraulic fluid to and from hydraulic cylinders 300 formed by the combination of tubes 115 and 125 with tubes 40 and 50, respectively.
  • open ends of tubes 115 and 125 are contained in the fourth end brace 110 and communicate with hydraulic ports formed in the fourth end brace 110.
  • each hydraulic port in the fourth end brace 110 communicates hydraulic fluid into hydraulic cylinders 305, for example, via an opening in the sidewalls of tubes 90 and 100, respectively.
  • Cylinders 305 are formed from the combination of tubes 190 and 205 with tubes 90 and 100, respectively.
  • tubes 190 and 205 are contained in the fifth end brace 175 and communicate with hydraulic ports formed in the fifth end brace 175.
  • each hydraulic port in the fifth end brace 175 communicates hydraulic fluid into tubes 185 and 200, respectively, for example, via an opening in the sidewalk of tubes 185 and 200.
  • Tubes 185 and 200 optionally communicate hydraulic fluid to cylinders 250, for example, via a hydraulic port formed in each of side braces 232.
  • any load carried by the free lift arrangement 245 moves first, followed by movement of the third section 20 with respect to the second section 15, followed by movement of the second section 15 with respect to the first section 10.
  • the reverse order occurs when pressurized hydraulic fluid leaves hydraulic circuit 290.
  • Movement of the third section 20 with respect to the second section 15 is optionally arrested by guides 225 and 235 engaging the fourth end brace 110 (Fig. 11).
  • Movement of the second section 15 with respect to the first section 10 is optionally arrested by guides 145 and 155 engaging the second end brace 60 (Fig. 10).
  • movement of the second section 15 with respect to the first section 10 and of the third section 20 with respect to the second section 15 may be limited by the stroke of hydraulic cylinders formed between the tubes of the first section 10, the second section 15, and the third section 20.
  • hydraulic circuit 290 is briefly described here, it may have components and functions similar to the hydraulic circuit described below with respect to Figs. 17-25.
  • modified hydraulic circuits may be used.
  • hydraulic paths may be defined by hoses external to one or more of tubes 115, 125, 40, 50, 190, 205, 90, and 100, and external to the fourth end brace 110, the fifth end brace 175, or both.
  • hydraulic valves may be included in a hydraulic circuit to modify operation of mast 5, for example, such that the third section 20 and the second section 15 move at substantially the same time, or intermittently with respect to each other.
  • fluid circuit 290 may include additional cylinders, for example,
  • such additional cylinders may communicate hydraulic fluid to tubes 90 and 100 via the fourth end brace 110, for example, via hydraulic ports formed in the fourth end brace 110.
  • such additional cylinders may communicate with a separate source of pressurized hydraulic fluid, or valves may be used, to form a hydraulic circuit that is isolated from hydraulic circuit 290.
  • a two-stage mast comprises a first section that is similar to the first section 10 and a second section that is similar to third section 20 movably connected to the first section.
  • a single-stage mast comprises a third section configured to attach to a lift truck, where such a third section is similar to the third section 20, but without tubes 190 and 205 and without guides 225, 230, 235, and 240.
  • an additional end brace may be included opposite end brace 175, and such additional end brace may include structure used to secure such a mast to a lift truck.
  • a single-stage mast does not need to include a free lift arrangement.
  • one or more additional sections similar to the second section 15 may be included to form a mast with more than three stages.
  • Mast 505 is similar to mast 5, with a difference that the first section 510, which is configured to be secured to a lift truck, is the inner mast section instead of being the outer mast section.
  • Mast 505 comprises a first section 510, a second section 515, and a third section 520.
  • the first section 510 nests within the second section 515 which in turn nests within the third section 520.
  • First section 510 of mast 505 may be considered an inner stage and comprises a first tube set 525 and a second tube set 530.
  • An optional first end brace 535 is secured proximate a first end of the tube sets 525 and 530 and is configured to be secured to a lift truck.
  • First end brace 535 may be secured to the tube sets 525 and 530 via an adhesive, an interference fit, welding, or other suitable securing manner. Securing the first end brace 535 to the tube sets 525 and 530 preferably does not breach any of the walls of tubes 540, 545, 550, or 555.
  • An optional second end brace 560 is secured proximate a second end of the tube sets 525 and 530 in the same manner as the first end brace 535.
  • Second section 515 comprises a third tube set 575 and a fourth tube set 580.
  • An optional third end brace 585 is secured proximate a first end of the tubes of the third tube set 575 and proximate a first end of the tubes of the fourth tube set 580.
  • Third end brace 585 is secured, for example, using one of the manners described with respect to the first end brace 535.
  • An optional fourth end brace 610 is secured proximate a second end of the third tube set 575 and proximate a second end of the second tube set 580, for example, using one of the manners described with respect to the first end brace 535.
  • Tube sets 575 and 580 may each comprise four tubes, three tubes, or other suitable number of tubes. In the illustrated embodiment, tube sets 575 and 580 each comprise four tubes; tubes 590, 595, 615, and 620 for tube set 575, and tubes 600, 605, 625, and 630 for tube set 580 (best illustrated in Fig. 22
  • At least one tube of tube set 575 is sized and dimensioned to fit within tube 540 or tube 545 of the first section 510.
  • one tube of tube set 575 is sized and dimensioned to fit within tube 540 and another tube of tube set 575 is sized and dimensioned to fit within tube 545 (Fig. 22).
  • at least one tube of tube set 580 is sized and dimensioned to fit within tube 550 or tube 555.
  • one tube of tube set 580 is sized and dimensioned to fit within tube 550 and another tube of tube set 580 is sized and dimensioned to fit within tube 555 (Fig. 22).
  • seals are included for mating tubes such that a combination of tubes forms a hydraulic cylinder.
  • Optional guides 645 and 650 are attached to the third tube set 575.
  • Guide 645 interacts with tube 545 of the fist tube set 525 and guide 650 interacts with tube 540 of the first tube set 525 to provide one or more of alignment, stability, and spacing between the first section 510 and the second section 515 when the second section 515 moves with respect to the first section 510.
  • Guide 645 may be attached to a side brace 640 and guide 650 may be attached to the third end brace 585.
  • Optional guides 655 and 660 are attached to the fourth tube set 580.
  • Guide 655 interacts with tube 555 of the second tube set 530 and guide 660 interacts with tube 550 of the second tube set 530 to provide one or more of alignment, stability, and spacing between the first section 510 and the second section 515 when the second section 515 moves with respect to the first section 510.
  • Guide 655 may be attached to a side brace 640 and guide 660 may be attached to the third end brace 585.
  • guides 645, 650, 655, and 660 are rollers, however such guides may comprise ball bearing sets, pads of low-friction material, or other suitable arrangements.
  • Third section 520 comprises a fifth tube set 665 and a sixth tube set 670.
  • An optional fourth end brace 675 is secured proximate a second end of the fifth tube set 665 and proximate a second end of the sixth tube set 670, for example, using one of the manners described with respect to the first end brace 535.
  • Tube sets 665 and 670 may each comprise four tubes, three tubes, or other suitable number of tubes. In the illustrated embodiment, tube sets 665 and 670 each comprise four tubes; tubes 680, 685, 686, and 690 for tube set 665, and tubes 695, 700, 705, and 706 for tube set 670 (best illustrated in Fig. 22).
  • At least one tube of the fifth tube set 665 is sized and dimensioned to fit within a tube of the third tube set 575 and at least one tube of the sixth tube set 670 is sized and dimensioned to fit within a tube of the fourth tube set 580.
  • two tubes of tube set 665 are sized and dimensioned to fit within two tubes of tube set 575 (Fig. 22) and two tubes of tube set 670 are sized and dimensioned to fit within two tubes of tube set 580 (Fig. 22).
  • seals are included for mating tubes such that a combination of tubes forms a hydraulic cylinder.
  • Optional guides 725 (Fig. 23) and 730 (Fig. 17) are attached to the fifth tube set 665.
  • Guide 725 interacts with one tube of the third tube set 575 and guide 730 interacts with another tube of the third tube set 575 to provide one or more of alignment, stability, and spacing between the second section 515 and the third section 520 when the third section 520 moves with respect to the second section 515.
  • Guide 725 may be attached to a side brace and guide 730 may be attached to another side brace.
  • Optional guides 735 and 740 are attached to the sixth tube set 670.
  • Guide 735 interacts with one tube of the fourth tube set 580 and guide 740 interacts with another tube of the fourth tube set 580 to provide one or more of alignment, stability, and spacing between the second section 515 and the third section 520 when the third section 520 moves with respect to the second section 515.
  • Guide 735 may be attached to a side brace and guide 740 may be attached to another side brace.
  • guides 725, 730, 735, and 740 are rollers, however such guides may comprise ball bearing sets, pads of low-friction material, or other suitable arrangements.
  • tube sets of the same section may have the same length, outer diameter, inner diameter, wall thickness, and be made from the same material, or a pair of tubes (one from a first tube set and one from a second tube set of the same section) may have the same length, outer diameter, inner diameter, and wall thickness while another pair of tubes (one from the first tube set and one from the second tube set of the same section) may have the same length, outer diameter, inner diameter, and wall thickness, any one or more of which may be different from the length, the outer diameter, the inner diameter, and the wall thickness of the other pair of tubes.
  • one or more intermediate braces such as intermediate braces 585, 635 and 710 (Fig. 17), are secured to one or more of the tube sets of the first stage 510, the second stage 515, and the third stage 520.
  • intermediate braces may be secured to multiple tubes of one tube set and to multiple tubes of another tube set.
  • intermediate brace 585 is secured to the tubes 590 and 595 of the tube set 575 and to the tubes 600 and 605 of the tube set 580 using one of the manners described above with respect to the first end brace 535.
  • intermediate braces increase stiffness and resistance to bending for one or more of the first section 510, the second section 515, and the third section 520.
  • Intermediate braces may be made from stamped, cast, or machined metal, such as steel or aluminum.
  • one or more side braces such as side braces 570, 640, and 720 (Fig.
  • a side brace is not secured to tubes of more than one tube set.
  • Side braces are preferably located between the first and second ends of a tube set.
  • Side braces are secured to the tubes of a tube set, for example, using one of the manners described above with respect to the first end brace 535.
  • side braces increase stiffness and resistance to bending for one or more of the first section 510, the second section 515, and the third section 520.
  • side braces are made from stamped, cast, or machined metal, such as steel or aluminum.
  • the number of, and location of, end braces, intermediate braces, side braces, or other suitable brace is a design consideration that depends on factors such as intended loads and use of the mast 505, the length of the tubes of the first tube set 525, the second tube set 530, the tubes of the third tube set 575, the tubes of the fourth tube set 580, the tubes of the fifth tube set 665, and the tubes of the sixth tube set 670, and the other physical dimensions and materials of the tubes of the first tube set 525, the second tube set 530, the tubes of the third tube set 575, the tubes of the fourth tube set 580, the tubes of the fifth tube set 665, and the tubes of the sixth tube set 670.
  • tube 706 is sized and dimensioned to fit within tube 605 (Fig. 22) and tube 705 is sized and dimensioned to fit within tube 600 (Fig. 22).
  • Tube 686 is sized and dimensioned to fit within tube 595 (Fig. 22), and tube 690 is sized and dimensioned to fit within tube 590 (Fig. 22).
  • seals are included such that each of the following combination of tubes forms a hydraulic cylinder: tubes 706 and 605, tubes 705 and 600, tubes 686 and 595, and tubes 690 and 590.
  • tube 630 is sized and dimensioned to fit within tube 555 (Fig. 22) and tube 625 is sized and dimensioned to fit within tube 550 (Fig. 22).
  • Tube 620 is sized and dimensioned to fit within tube 545 (Fig. 22), and tube 615 is sized and dimensioned to fit within tube 540 (Fig. 22).
  • seals are included such that each of the following combination of tubes forms a hydraulic cylinder: tubes 630 and 555, tubes 625 and 550, tubes 620 and 545, and tubes 615 and 540.
  • a combination of tubes may serve as a guide or alignment mechanism.
  • additional tubes may be included to function as
  • additional hydraulic cylinders or as guiding elements to provide one or more of alignment, stability, and spacing for one or more of the first stage 510, the second stage 515, and the third stage 520.
  • the third section 520 optionally includes a free lift arrangement 745 (Fig. 18).
  • Free lift arrangement 745 comprises two hydraulic cylinders 750, one attached proximate the fifth tube set 665 and the other attached proximate the sixth tube set 670.
  • both hydraulic cylinders 750 are attached to the tube sets 665 and 670 via side braces 720 and are secured to the side braces 720 via adhesive, welding, interference fit or other suitable attachment manner.
  • Pulleys 755 are optionally arranged such that an axis through the center of
  • rotation for each pulley 755 is configured to be substantially aligned with a longitudinal axis 265 of a lift truck 270 (Fig. 13) when mast 505 is installed on lift truck 270.
  • pulleys such as pulleys 755
  • lift chains 776 are secured at a first end to a portion of the third section 520, run over a pulley 755, and are secured to carriage 772.
  • header hoses 775 are hydraulically coupled to carriage 772, run over pulleys 755, run over second pulleys 756 (Fig.
  • the third section 520 is nested over the second section 515, and the combination of the second section 515 and third section 520 is nested over the first section 510 to form mast 505.
  • Mast 505 is attached to lift truck 270 such that mast 505 may be tilted, for example, by using hydraulic cylinders 274 (Fig. 13), or may be rigidly attached to lift truck 270.
  • a hydraulic circuit communicates from hydraulics of lift truck 270 to and
  • Hydraulic hoses fluidly connect the hydraulic circuit of mast 505 with hydraulics of lift truck 270 and communicate hydraulic fluid to and from hydraulic cylinders formed by the combination of tubes 540 with 615 (Fig. 22) and of tubes 590 with 690 (Fig. 22) on one side of the mast 505 and communicate hydraulic fluid to and from hydraulic cylinders formed by the combination of tubes 550 with 625 (Fig. 22) and of tubes 600 with 705 (Fig. 22) on the other side of the mast 505. Hydraulic fluid is communicated to cylinders 750 via tubes 682 and 695 (Fig. 23).
  • a seal 541 (Fig. 24), such as a seal described above, a gasket, an o-ring, or other suitable device, prevents fluid from exiting the top of tube 540.
  • the top of tube 615 is open and communicates the pressurized fluid into a port 611 formed in the end brace 610.
  • a tube 612 communicates with the port 611 at one end and with a fluid coupler 613 at the other.
  • Fluid coupler 613 fluidly communicates with the interior of tube 590 such that pressurized hydraulic fluid enters proximate to the top of tube 590. Fluid flows into tube 590, specifically, in the annular space between the interior of tube 590 and the exterior of tube 690 (best illustrated in Fig. 22), as represented by arrow "F2" (Fig. 23) and enters the open bottom end of tube 690. Pressurized hydraulic fluid then flows through the interior of tube 690 to the top of tube 690 as represented by arrow "F3" (Fig. 23).
  • a seal which may be similar to seal 541, prevents fluid from exiting the top of tube 590.
  • the top of tube 690 is open and communicates the pressurized fluid into a port formed in the end brace 675, which may be similar to port 611 (Fig. 24).
  • a fluid coupler 676 communicates the port formed in the end brace 675 with a tube 677 and the tube 677 communicates with a fluid coupler 678.
  • Fluid coupler 678 fluidly communicates with the interior of tube 680 such that pressurized hydraulic fluid enters proximate to the top of tube 680 and flows towards the bottom of tube 680 as represented by arrow "F4" (Fig. 23).
  • the top of tube 680 is blocked to prevent hydraulic fluid from passing therethrough. Fluid flows down tube 680 and enters the fluid coupler 681 (Fig. 25) which communicates the fluid to a pipe 682, through another fluid coupler 683 and into cylinder 750.
  • a complimentary second fluid circuit exists through tubes 550, 625, through the end brace 610 to tubes 600, 705, through the end brace 675 to tube 695 and into the other cylinder 750.
  • pressurized hydraulic fluid passes through the first and second hydraulic circuits, that is, through cylinders formed by tubes 550 and 625 and by tubes 600 and 705 and through tube 695 to cylinder 750 on one side of mast 505 and through cylinders formed by tubes 540 and 615 and by tubes 590 and 690 and through tube 680 to cylinder 750 on the other side of mast 505.
  • pressurized hydraulic fluid enters cylinders 750, such fluid causes the fork carriage 772 to move from its lowermost position with respect to the third stage 520 (Fig. 18) to its uppermost position with respect to the third stage 520 (Fig.
  • the pressurized hydraulic fluid in the cylinders formed by tubes 600 and 705 and by tubes 590 and 690 causes the third stage 520 to move from its lowermost position with respect to the second stage 515 (Fig. 19) to its uppermost position with respect to the second stage 515 (Fig. 20).
  • the pressurized hydraulic fluid in the cylinders formed by tubes 550 and 625 and by tubes 540 and 615 causes the second stage 515 to move from its lowermost position with respect to the first stage 510 (Fig. 20) to its uppermost position with respect to the first stage 510 (Fig. 17).
  • the stages 515 and 520 and the fork carriage 772 move in reverse order, that is the second stage 515 lowers, then the third stage 520 lowers, then the fork carriage 772 lowers.
  • one or more valves may be included in the hydraulic circuits to alter the order, the manner, or both, in which the fork carriage 772, third stage 520, and second stage 515 move.
  • additional hydraulic circuits to supply the fork carriage 772 may be included in the mast 505.
  • a third hydraulic circuit may exist through tube 545 and through tube 555 to header hoses 775 via ports formed in optional second end brace 560.
  • a method lifts a load attached to a mast on a lift truck.
  • the load may be attached to the mast by means of forks attached to the mast and supporting the load, or by other means.
  • the method comprises moving a set of inner tubes vertically and slidingly in unison within a corresponding set of outer tubes, as described, for example, above.
  • the set of inner tubes and the corresponding set of outer tubes are aligned along common respective longitudinal axes tube-by-tube.
  • the set of inner tubes may be part of the top or third section of the mast, and the set of outer tubes may be part of the middle or second section.
  • the set of inner tubes may be part of the middle or second section of the mast, and the set of outer tubes may be part of the bottom or third section.
  • the set of inner tubes structurally bears the weight of the load.
  • the set of outer tubes may structurally bear the combined weight of the load and the set of inner tubes.
  • the method may optionally further comprise increasing pressure of a hydraulic fluid within the set of outer tubes to thereby cause the set of inner tubes to move relative to the set of outer tubes by piston-cylinder action.
  • the number of tubes in each of the set of inner tubes and the set of outer tubes is at least three, preferably four according to the embodiments illustrates therein. Two of the four sets of inner tubes and outer tubes may be on a left side of the lift truck and the other two of the four sets of inner tubes and outer tubes may be on a right side of the lift truck.
  • the mast used in the method may optionally be a three-section mast, wherein said inner set of tubes is part of a top section of the three-section mast, wherein said outer set of tubes is part of a middle section of the three-section mast, and wherein a bottom section of the three-section mast comprises a third set of tubes.
  • the method may further comprise moving the middle section of the three-section mast relative to the bottom section of the three-stage mast by moving tubes attached to the middle section vertically and slidingly in unison within the third set of tubes and structurally bearing, by the third set of tubes, the combined weight of the load, the set of inner tubes, and the set of outer tubes.
  • the mast used in the method may optionally have a coaxial tube-in-tube-in-tube design.
  • Figs 27-30 illustrate another embodiment, which does not include intermediate braces.
  • the intermediate braces, 65, 135, 210, 215, 585, 635, and 710 are optional.
  • Figs 27-30 illustrate an embodiment without any such intermediate braces. If included, the intermediate braces provide additional structural strength to the mast sections, thereby allowing the various tubes to be designed to have less structural load- bearing strength per se. However, if the tubes have sufficient structural strength without intermediate braces, then the mast design can be simplified, such as shown in Figs. 27-30, which illustrates a tube-in-tube-in-tube design for a three-section mast 5B. The height of each section is approximately equal, as shown, but that need not be the case.
  • the mast 5B includes a first section 10B, a second section 15B, and a third
  • the first section 10B is the bottom, outer section; the second section 15B is the middle section; and the third section 20B is the upper, inner section, as illustrated.
  • the section it is also possible for the section to be arranged differently, such as, for example, the bottom section being constructed from the inner-most tubes while the top section is constructed from the outer-most tubes.
  • the first section 10B comprises four tubes 40 A, 45A, 50A, and 55A.
  • the tubes 40A and 45A are on one side (left, as illustrated, or right, from the driver's perspective), and the tubes 50A and 55A are on the other side.
  • the tubes 40A and 50A are toward the back of the mast 5B, closer to the driver, while the tubes 45A and 55A are further forward.
  • the tubes 40A, 45A, 50A, and 55A preferably have the same dimensions and are made of the same material.
  • the tubes 40A, 45A, 50A, and 55A may be the same as the tubes 40, 45, 50, and 55 described earlier with respect to another embodiment.
  • the second section 15B comprises four tubes 90A, 95A, 125A, and 130A.
  • the tubes 90A and 95A are on one side (left, as illustrated, or right, from the driver's perspective), and the tubes 125A and 130A are on the other side.
  • the tubes 90A and 125A are toward the back of the mast 5B, closer to the driver, while the tubes 95A and 130A are further forward.
  • the tubes 90A, 95A, 125A, and 130A preferably have the same dimensions and are made of the same material.
  • the tubes 90A, 95A, 125A, and 130A may be the same as the tubes 90, 95, 125, and 130 described earlier with respect to another embodiment.
  • the interiors of tubes 40A, 45A, 50A, and 55A function as cylinders around respective pistons formed by the tubes, 90A, 95A, 125A, and 130A.
  • the external diameters of the tubes 90A, 95A, 125A, and 130A are the same or slightly less than the internal diameters of the tubes 40A, 45A, 50A, and 55A, respectively, such that the tubes 90A, 95A, 125A, and 130A can slide within the interiors of the tubes 40A, 45A, 50A, and 55A, respectively.
  • the third section 20B comprises four tubes 180A, 185A, 195A, and 200A.
  • the tubes 180A and 185A are on one side (left, as illustrated, or right, from the driver's perspective), and the tubes 195A and 200A are on the other side.
  • the tubes 180A and 195A are toward the back of the mast 5B, closer to the driver, while the tubes 185A and 200A are further forward.
  • the tubes 180A, 185A, 195A, and 200A preferably have the same dimensions and are made of the same material.
  • the tubes 180A, 185A, 195A, and 200A may be the same as the tubes 180, 185, 195, and 200 described earlier with respect to another embodiment.
  • the interiors of tubes 90A, 95A, 125A, and 130A function as cylinders around respective pistons formed by the tubes, 180A, 185A, 195A, and 200A.
  • the external diameters of the tubes 180A, 185A, 195A, and 200A are the same or slightly less than the internal diameters of the tubes 90A, 95A, 125A, and 130A, respectively, such that the tubes 180A, 185A, 195A, and 200A can slide within the interiors of the tubes 90A, 95A, 125A, and 130A, respectively.
  • Each inner tube is moved within its respective mating outer tube by pressure of hydraulic fluid, which may be a gas or a liquid, preferably an incompressible or slightly compressible liquid.
  • hydraulic fluid which may be a gas or a liquid, preferably an incompressible or slightly compressible liquid.
  • the seal is preferably provided on one or both ends of the tubes 180A, 185A, 195A, and 200A.
  • At or near the top ends of the intermediate tubes 90A, 95A, 125A, and 130A and/ or the bottom ends of the top tubes 180A, 185A, 195A, and 200A is a mechanical stop to prevent the top tubes 180A, 185A, 195A, and 200A from completely exiting the intermediate tubes 90A, 95A, 125A, and 130A during normal operation, such as previously described with respect to other embodiments.
  • the intermediate tubes 90A, 95A, 125A, and 130A is a mechanical stop to prevent the intermediate tubes 90A, 95A, 125A, and 130A from completely exiting the intermediate tubes bottom tubes 40A, 45A, 50A, and 55A during normal operation, such as previously described with respect to other embodiments.
  • increasing pressure of the hydraulic fluid first causes the upper, third section 20B to raise relative to the intermediate, second section 15B as the tubes 180A, 185A, 195A, and 200A are pushed up within the inner cylinders of the tubes 90A, 95A, 125A, and 130A.
  • Increased increased pressure of the hydraulic fluid then causes the intermediate, second section 15B to raise relative to the bottom, first section 10A as the tubes 90A, 95A, 125A, and 130A are pushed up within the inner cylinders of the tubes 40A, 45A, 50A, and 55A.
  • the mast 5B can be designed so that the sections are raised in a different (e.g., the opposite) order or simultaneously.
  • each of the four piston-cylinder combinations for the same section-to-section interface have approximately the same designs so that they move in approximate unison under equal hydraulic pressure, which is preferably provided approximately equally from a common source.
  • the first section 10B also comprises a bottom brace 35B, a top brace 60B, and a plurality of side braces 70B.
  • the bottom brace 35B and the top brace 60B may be like the end braces 35 and 65 previously described with respect to another embodiment.
  • the side braces 70B may be like the side braces 70 previously described with respect to another embodiment.
  • three side braces are illustrated on each of the left and right sides, more or less (or none) may be included.
  • the first section 10B may include one or more intermediate braces like the intermediate brace 65 previously described with respect to another embodiment.
  • the second section 15B also comprises a top brace 110B, which may be like the end brace 110 previously described with respect to another embodiment.
  • the third section 15B also comprises a top brace 175B, which may be like the end brace 175 previously described with respect to another embodiment.
  • side braces are not employed in the second or third sections 15B or 20B.
  • the third section 20B includes two channels 800 and 805 on the right and left (from the driver's perspective), respectively.
  • Each channel 800 and 805 is an elongate U- shaped piece with a length that is approximately equal to the height of each mast section.
  • Each channel 800 and 805 is attached to the top of the top brace 175B, as shown, one on the left side and one of the right side, with the open ends of each U facing inward toward each other.
  • the channels 800 and 805 are preferably spaced apart from each other by an approximately uniform distance along their lengths so as to accept a fork carriage, such as the fork carriage 272 describe above, or other carriage assembly with the channels 800 and 805.
  • Figs. 27-30 illustrate four tubes per section
  • the number of tubes per section could be more or less than four.
  • the number of tubes per section could be, for example, six, with three tubes on each of the left and right side of each section.
  • a single three-section tube-in-tube-in-tube design is also possible, in which case a single channel or other structure may be affixed to the top of the uppermost section offset and forward from the common cylindrical axis of tubes.
  • a modified fork carriage or other suitable carriage assembly may be attached to that structure.
  • a single tube embodiment may be designed to permit rotation about the common cylindrical axis of the tubes to enhance maneuverability of the forks, especially where the fork assembly is extendible/retractable in a horizontal direction.
  • Fig. 26 illustrates an embodiment comprising side braces 70A that are made from a cold rolled formed metal.
  • side braces 70A may be formed from an injection molded or extruded plastic, a fiber and resin material, or other suitable material.
  • side braces 70A comprise channels 71A shaped and sized to receive tubes 40A, 45A, 50A, and 55A.
  • Side braces 70A are attached to tubes 40A, 45A, 50A, and 55A, for example, with an interference fit between tubes 40A, 45A, 50A, and 55A and channels 71 A, via an adhesive, welding, or other suitable manner.
  • a web 72A extends between the channels 71 A.
  • web 72A includes one or more cut-outs 73A to reduce weight.
  • Side braces 70A are illustrated as extending between end braces 35A and 60A, but side braces, such as side braces 70A, may be shorter.
  • more than one side brace, such as side brace 70A may be included on a side of section 10A, especially when such side braces are shorter than the length of tubes 40A, 45A, 50A, and 55A.
  • an intermediate brace may be included with side braces, such as side braces 70A.

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  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Structural Engineering (AREA)
  • Civil Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Mechanical Engineering (AREA)
  • Forklifts And Lifting Vehicles (AREA)

Abstract

L'invention concerne des éléments tubulaires (40, 40A, 45, 45A, 50, 50A, 55, 55A, 90, 95, 100, 105, 180, 185, 190, 195, 200, 205, 540, 545, 550, 555, 590, 595, 600, 605, 615, 620, 625, 630, 680, 685, 690, 695, 700, 705, 706) qui sont utilisés pour construire la structure de support pour un mât (5, 505) d'un chariot élévateur (270). Des vérins hydrauliques peuvent être intégrés dans la structure tubulaire (40, 40A, 45, 45A, 50, 50A, 55, 55A, 90, 95, 100, 105, 180, 185, 190, 195, 200, 205, 540, 545, 550, 555, 590, 595, 600, 605, 615, 620, 625, 630, 680, 685, 690, 695, 700, 705, 706). Des entretoises (35, 35A, 60, 65, 65A, 70, 70A, 85, 110, 135, 140, 147, 175, 210, 215, 220, 227, 232, 535, 560, 570, 585, 610, 635, 640, 675, 710, 720) peuvent être incluses pour modifier une ou plusieurs caractéristiques parmi la rigidité, la résistance à la torsion et la résistance à la flexion pour un tel mât (5, 505).
PCT/US2018/021810 2017-03-09 2018-03-09 Mât de chariot élévateur ayant des tubes comme éléments structuraux et/ou hydrauliques WO2018165587A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE212018000179.0U DE212018000179U1 (de) 2017-03-09 2018-03-09 Gabelstaplermast mit Rohren als Strukturelemente und/oder hydraulische Elemente
CN201890000599.0U CN211110874U (zh) 2017-03-09 2018-03-09 用于叉车的桅杆

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US201762469054P 2017-03-09 2017-03-09
US62/469,054 2017-03-09

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Citations (7)

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EP1151959A1 (fr) * 2000-05-04 2001-11-07 Rocla Oyj Chariot élévateur avec un mât extensible
US6505710B1 (en) * 1997-10-14 2003-01-14 Nissan Motor Co., Ltd. Mast apparatus for fork lift trucks
US20060027094A1 (en) * 2004-05-06 2006-02-09 Jungheinrich Aktiengesellschaft Industrial truck having a piston/cylinder arrangement and improved cylinder mounting
US20090032338A1 (en) * 2007-08-01 2009-02-05 Wiggins Lift Co., Inc. Three stage mast
US20110091306A1 (en) * 2009-10-20 2011-04-21 Francois Roux Free lift mast for truck mounted forklift
US20170073203A1 (en) * 2015-09-16 2017-03-16 Hyster-Yale Materials Handling Group, Inc. Forklift trucks and masts therefore

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3930563A (en) * 1972-07-06 1976-01-06 Linde Aktiengesellschaft Lift vehicle
US6505710B1 (en) * 1997-10-14 2003-01-14 Nissan Motor Co., Ltd. Mast apparatus for fork lift trucks
EP1151959A1 (fr) * 2000-05-04 2001-11-07 Rocla Oyj Chariot élévateur avec un mât extensible
US20060027094A1 (en) * 2004-05-06 2006-02-09 Jungheinrich Aktiengesellschaft Industrial truck having a piston/cylinder arrangement and improved cylinder mounting
US20090032338A1 (en) * 2007-08-01 2009-02-05 Wiggins Lift Co., Inc. Three stage mast
US20110091306A1 (en) * 2009-10-20 2011-04-21 Francois Roux Free lift mast for truck mounted forklift
US20170073203A1 (en) * 2015-09-16 2017-03-16 Hyster-Yale Materials Handling Group, Inc. Forklift trucks and masts therefore

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CN211110874U (zh) 2020-07-28

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