High visibility lift apparatus

{
  "publication_number": "US4365693A",
  "country": "US",
  "kind": "A",
  "title": "High visibility lift apparatus",
  "abstract": "Apparatus (10) for lifting or moving loads require high operator visibility and simplicity of construction. For example, in a mast assembly (10) such as can be used on a fork lift truck or other cargo handler it is desirable to maximize visibility through spaced-apart uprights (16,18,24,26). Also, free lift of a carriage (14) which engages the load will maximize visibility in that the movable uprights (16,18) will not be elevated above the fixed uprights (24,26) when raising the carriage (14) to move the load. In the apparatus (10), first and second lifting elements (32,34) or jacks (36,38) are mounted adjacent the uprights (16,24;18,26) for visibility. The lifting elements (32,34) are interconnected by a load sharing member (48) for free lift and to distribute the forces encountered in raising the load more equally between the lifting elements (32,34) and the chains (52', 52\").",
  "claims": [
    "1. Apparatus (10), comprising: a frame (28); a first member (12) mounted on and movable relative to said frame (28); a second member (14) mounted on and movable relative to said first member (12) and movable relative to said frame (28); first and second lifting elements (32,34) each having a movable lifting portion (40,42) and each being connected to said frame (28), said lifting portions (40,42) each being movable between a first position at which said second member (14) is movable thereby and said first member (12) is free from being movable and a second position at which said first and second members (12,14) are both movable thereby, and being movable one relative to the other; a load sharing member (48) connected to said lifting portions (40,42) of both of said first and second lifting elements (32,34) and being movable partially about each of said connections with said lifting portions (40,42) in response to relative movement of said lifting elements (32,34), and being movable relative to said first member (12) in response to at least one of said lifting portions (40,42) moving from its first position toward its second position and movable with said first member (12) in response to at least one of said lifting portions (40,42) being at its second position; and means (50) for interconnecting said first and second lifting elements (32,34) and said second member (14) for moving said second member (14) in response to moving at least one of said lifting portions (40,42) of said first and second lifting elements (32,34).",
    "2. The apparatus (10), as set forth in claim 1, wherein said interconnecting means (50) includes a flexible tension member (52) connected to said frame (28) and to said second member (14).",
    "3. The apparatus (10), as set forth in claim 2, including a sheave (58) connected to said load sharing member (48) and wherein said flexible tension member (52) passes about said sheave (58).",
    "4. The apparatus (10), as set forth in claim 1, including guide means (74) for maintaining preselected alignment of said load sharing member (48) and said first member (12) in response to moving said lifting portions (40,42) of said first and second lifting elements (32,34) between their first and second positions.",
    "5. The apparatus (10), as set forth in claim 4, wherein said guide means (74) includes a guide pin (78) connected to said first member (12) and a guide arm (80) carried by said load sharing member (48) and positioned about and movable along said guide pin (78).",
    "6. The apparatus (10), as set forth in claim 1, including pins (62,64) each positioned through a respective one of said lifting portions (40,42) of said first and second lifting elements (32,34) and through said load sharing member (48) and wherein partial movement of said load sharing member (48) is about said pins (62,64).",
    "7. The apparatus (10), as set forth in claim 6, wherein each of said lifting portions (40,42) of said first and second lifting elements (32,34) has a seat (66) positioned immediately adjacent and in contactable relationship with said load sharing member (48) and forces exerted on said load sharing member (48) from said lifting portions (40,42) in moving said lifting portions (40,42) from their first toward their second positions are passed through said seats (66) onto said load sharing member (48).",
    "8. A mast assembly (10), comprising: a frame (28); first and second fixed uprights (24,26) spaced one from the other and connected to said frame (28); a movable upright assembly (12) having first and second movable uprights (16,18) mounted on and movable along said first and second fixed uprights (24,26), respectively; a carriage (14) mounted on and movable relative to said first and second movable uprights (16,18); first and second jacks (36,38) each having lifting (40,42) and housing (44,46) portions and being associated with said frist and second fixed uprights (24,26), respectively, said housing portions (44,46) each being substantially fixed relative to said first and second fixed uprights (24,26), said lifting portions (40,42) each being controllably movable between first and second positions relative to their respective related housing portion (44,46) and being movable one relative to the other; a load sharing member (48) connected to said lifting portions (40,42) of said first and second jacks (36,38) and movable in response to moving said lifting portions (40,42), at said first positions of said lifting portions (40,42) said load sharing member (48) being movable partially about each of said connections with said lifting portions (40,42) in response to relative movement of said lifting portions (40,42) and movable relative to said movable upright assembly (12), and at said second positions of said lifting portions (40,42) said load sharing member (48) being engageable with said movable upright assembly (12) and said load sharing member (48) and said movable upright assembly (48) being movable one with the other; a sheave (58) carried by said load sharing member (48); and a chain (52) connected to a preselected one of said first and second fixed uprights (24,26) and to said carriage (14) and passing about said sheave (58).",
    "9. The mast assembly (10), as set forth in claim 8, wherein said movable upright assembly (12) defines an engaging pad (82) and said load sharing member (48) is urged into contact with said engaging pad (82) at said second position of said load sharing member (48).",
    "10. The apparatus (10), as set forth in claim 8, including pins (62,64) each positioned through a respective one of said lifting portions (40,42) of said first and second lifting elements (32,34) and through said load sharing member (48) and wherein said partial movement of said load sharing member (48) is pivotally about said pins (62,64).",
    "11. The apparatus (10), as set forth in claim 8, wherein said lifting portions (40,42) seat with said load sharing member (48) for maintaining surface contact with said load sharing member (40) when said load sharing member (48) partially moves about its connections with said lifting portions (40,42).",
    "12. The apparatus, as set forth in claim 8, including a guide pin (78) connected to said movable upright assembly (12) and a guide arm (80) carried by said load sharing member (48) and positioned about and movable along said guide pin (78).",
    "13. The apparatus, as set forth in claim 12, including a stop (88) positioned on said guide pin (78) and wherein said guide arm (80) and said load sharing member (48) are located between said stop (88) and the connection of said guide pin (78) to said movable upright and wherein said load sharing member (48) is contactable with said stop (88) in response to moving said lifting portions (40,42) from their second toward their first positions.",
    "14. Apparatus (10) comprising: a frame (28); a first member (12) mounted on and movable relative to said frame (28); a second member (14) mounted on and movable relative to said first member (12) and movable relative to said frame (28); first and second lifting elements (32,34) each having a movable lifting portion (40,42) and each being connected to said frame (28), said lifting portions (40,42) each being movable between a first position at which said second member (14) is movable thereby and said first member (12) is free from being movable and a second position at which said first and second members (12,14) are both movable thereby; a load sharing member (48) connected to said lifting portions (40,42) of both of said first and second lifting elements (32,34) and being movable relative to said first member (12) in response to at least one of said lifting portions (40,42) moving from its first position toward its second position and movable with said first member (12) in response to at least one of said lifting portions (40,42) being at its second position. means (50) for interconnecting said first and second lifting elements (32,34) and said second member (14) for moving said second member (14) in response to moving at least one of said lifting portions (40,42) of said first and second lifting elements (32,34); and guide means (74) for maintaining preselected alignment of said load sharing member (48) and said first member (12) in response to moving said lifting portions (40,42) of said first and second lifting elements (32,34) between their first and second positions, said guide means (74) including a guide pin (78) connected to said first member (12) and a guide arm (80) carried by said load sharing member (48) and positioned about and movable along said guide pin (78).",
    "15. The apparatus (10), as set forth in claim 14, including pins (62,64) each positioned through a respective one of said lifting portions (40,42) of said first and second lifting elements (32,34) and through said load sharing member (48) and wherein said load sharing member (48) is movable about said pins (62,64).",
    "16. The apparatus (10), as set forth in claim 14, wherein said guide arm (80) contacts said first member (12) at the second position of at least one of said lifting portions (40,42)."
  ],
  "cpc": [
    "B32B 21/02",
    "B32B 2262/105",
    "B32B 2307/202",
    "B32B 27/08",
    "B32B 27/32",
    "B32B 27/36",
    "B32B 5/02",
    "D21H 11/00",
    "D21H 13/02",
    "D21H 13/50",
    "D21H 5/12",
    "H01B 1/24",
    "H05B 3/145"
  ],
  "assignees": [
    "TOWMOTOR CORP"
  ],
  "filing_date": "1980-10-03",
  "publication_date": "1982-12-28",
  "grant_date": "1982-12-28",
  "priority_date": "1982-08-30",
  "application_number": "US-26601180-A",
  "family_id": "22168166",
  "citations": [
    "GB1396715A",
    "US2456320A",
    "US3394778A",
    "US4030568A",
    "US4053139A",
    "US4191276A",
    "US4219302A"
  ]
}