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A spring system for relatively displacing elements attached to end mounts of the rod assembly comprises a housing having a rod member movable between extended and retracted positions relative thereto, and a first compression spring in the housing surrounded by a second compression spring for biasing

A spring system for relatively displacing elements attached to end mounts of the rod assembly comprises a housing having a rod member movable between extended and retracted positions relative thereto, and a first compression spring in the housing surrounded by a second compression spring for biasing the rod member to one of an extended or retracted position relative to the housing. The two springs are oppositely wound whereby, from a compressed condition, the spring rod exerts an expansion force which increases at a linear rate. The spring system includes a valve arrangement to control the rate at which the spring rod moves from a retracted position to an extended position.

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1. A spring system comprising a housing having an axis, an internal chamber, and axially opposite bottom and top ends; a rod member coaxial with said axis and positioned within said internal chamber and having an inner end in said housing and an outer end axially outwardly of said top end of said ho

1. A spring system comprising a housing having an axis, an internal chamber, and axially opposite bottom and top ends; a rod member coaxial with said axis and positioned within said internal chamber and having an inner end in said housing and an outer end axially outwardly of said top end of said housing; a guide member on said inner end of said rod member supporting said rod member for reciprocation axially of said housing between retracted and extended positions relative thereto; first and second compression springs each extending between said guide member and the bottom end of said housing; and top and bottom bushings, said top bushing positioned at least closely adjacent to said top end of said housing and said bottom bushing positioned at least closely adjacent to said bottom end of said housing; said top bushing including an opening to enable a portion of said rod member to pass therethrough and to support said rod member for reciprocation axially of said housing between retracted and extended positions relative thereto, said top bushing including a sealing arrangement positioned at least closely adjacent to a bottom of said top bushing to inhibit fluid from entering into and escaping from said internal chamber between said top bushing and said top end of said housing, said first and second springs being coaxial with one another and with said axis, at least one of said springs at least partially applying a force on said guide member as said rod member moves between fully retracted and fully extended positions, said guide member designed to move into engagement with or move to a position closely adjacent to said top bushing when said rod member moves to a fully extended position, at least one of said springs having a free length that is at least a majority length of said internal chamber, both of said springs contacting said bottom bushing when said rod member in said fully retracted position, said guide member dividing said internal chamber into at least two sub-chambers, said guide member including a first passageway that at least partially regulates fluid flow between said at least two sub-chambers during said reciprocation of said rod member, said first passageway fully spaced from an outer edge of said guide member and passing fully through said guide member, said outer end of said rod member including a mounting element. 2. The spring system as defined in claim 1, wherein the direction of winding of said first compression spring is opposite to the direction of winding of said second compression spring. 3. The spring system as defined in claim 2, wherein the free length of said first compression spring is different from the free length of said second compression spring. 4. The spring system as defined in claim 3, wherein the outside diameter of said first compression spring is less than the outside diameter of said second compression spring. 5. The spring system as defined in claim 4, wherein the wire diameter of said first compression spring is less than the wire diameter of said second compression spring. 6. The spring system as defined in claim 2, wherein the outside diameter of said first compression spring is less than the outside diameter of said second compression spring. 7. The spring system as defined in claim 2, wherein the wire diameter of said first compression spring is less than the wire diameter of said second compression spring. 8. The spring system as defined in claim 2, wherein the outside diameter and wire diameter of said first compression spring are respectively less than the outside diameter and wire diameter of said second compression spring. 9. The spring system as defined in claim 8, wherein said first passageway in said guide member includes a one way valve arrangement. 10. The spring system as defined in claim 9, wherein said guide member includes a second passageway, said second passageway fully spaced from an outer edge of said guide member and spaced from said first passageway, said second passageway not in fluid communication with said first passageway. 11. The spring system as defined in claim 10, wherein said second passageway has a maximum fluid flow rate that is less than a maximum fluid flow rate of said first passageway. 12. The spring system as defined in claim 11, wherein said second passageway allows for fluid flow in both directions. 13. The spring system as defined in claim 10, wherein said second passageway allows for fluid flow in both directions. 14. The spring system as defined in claim 2, wherein said first passageway in said guide member includes a one way valve arrangement. 15. The spring system as defined in claim 14, wherein said guide member includes a second passageway, said second passageway fully spaced from an outer edge of said guide member and spaced from said first passageway, said second passageway not in fluid communication with said first passageway. 16. The spring system as defined in claim 15, wherein said second passageway has a maximum fluid flow rate that is less than a maximum fluid flow rate of said first passageway. 17. The spring system as defined in claim 16, wherein said bottom end is sealed to substantially prevent fluid flow through said bottom end. 18. The spring system as defined in claim 17, wherein said top end is sealed to substantially prevent fluid flow through said top end. 19. The spring system as defined in claim 18, wherein said second passageway allows for fluid flow in both directions. 20. The spring system as defined in claim 17, wherein said top end includes a passageway to allow for a controlled rate of fluid flow to exit said internal chamber as said rod member moves to said extended position. 21. The spring system as defined in claim 20, wherein said passageway in said top end is spaced from said rod member. 22. The spring system as defined in claim 20, wherein said passageway in said top end is adjacent to said rod member. 23. The spring system as defined in claim 16, wherein said top end is sealed to substantially prevent fluid flow through said top end. 24. The spring system as defined in claim 16, wherein said top end includes a passageway to allow for a controlled rate of fluid flow to exit said internal chamber as said rod member moves to said extended position. 25. The spring system as defined in claim 15, wherein said second passageway allows for fluid flow in both directions. 26. The spring system as defined in claim 2, wherein said guide member includes a second passageway, said second passageway fully spaced from an outer edge of said guide member and spaced from said first passageway, said second passageway not in fluid communication with said first passageway. 27. The spring system as defined in claim 26, wherein said second passageway has a maximum fluid flow rate that is less than a maximum fluid flow rate of said first passageway. 28. The spring system as defined in claim 1, wherein the free length of said first compression spring is different from the free length of said second compression spring. 29. The spring system as defined in claim 1, wherein the outside diameter of said first compression spring is less than the outside diameter of said second compression spring. 30. The spring system as defined in claim 1, wherein the wire diameter of said first compression spring is less than the wire diameter of said second compression spring. 31. The spring system as defined in claim 30, wherein the outside diameter and wire diameter of said first compression spring are respectively less than the outside diameter and wire diameter of said second compression spring. 32. The spring system as defined in claim 1, wherein the outside diameter and wire diameter of said first compression spring are respectively less than the outside diameter and wire diameter of said second compression spring. 33. The spring system as defined in claim 1, wherein said first passageway in said guide member includes a one way valve arrangement. 34. The spring system as defined in claim 33, wherein said guide member includes a second passageway, said second passageway fully spaced from an outer edge of said guide member and spaced from said first passageway, said second passageway not in fluid communication with said first passageway. 35. The spring system as defined in claim 34, wherein said second passageway has a maximum fluid flow rate that is less than a maximum fluid flow rate of said first passageway. 36. The spring system as defined in claim 35, wherein said second passageway allows for fluid flow in both directions. 37. The spring system as defined in claim 34, wherein said second passageway allows for fluid flow in both directions. 38. The spring system as defined in claim 1, wherein said guide member includes a second passageway, said second passageway fully spaced from an outer edge of said guide member and spaced from said first passageway, said second passageway not in fluid communication with said first passageway. 39. The spring system as defined in claim 38, wherein said second passageway has a maximum fluid flow rate that is less than a maximum fluid flow rate of said first passageway. 40. The spring system as defined in claim 1, wherein said bottom end is sealed to substantially prevent fluid flow through said bottom end. 41. The spring system as defined in claim 40, wherein said top end is sealed to substantially prevent fluid flow through said top end. 42. The spring system as defined in claim 40, wherein said top end includes a passageway to allow for a controlled rate of fluid flow to exit said internal chamber as said rod member moves to said extended position. 43. The spring system as defined in claim 1, wherein said top end is sealed to substantially prevent fluid flow through said top end. 44. The spring system as defined in claim 1, wherein said top end includes a passageway to allow for a controlled rate of fluid flow to exit said internal chamber as said rod member moves to said extended position. 45. The spring system as defined in claim 44, wherein said passageway in said top end is spaced from said rod member. 46. The spring system as defined in claim 44, wherein said passageway in said top end is adjacent to said rod member. 47. The spring system as defined in claim 1, including a guide rod that extends from said guide member toward said bottom end coaxial with said axis and said first compression spring surrounds said guide rod. 48. The spring system as defined in claim 1, including at least a third compression spring, said third compression spring extending between said guide member and said bottom end of said housing coaxial with said axis. 49. The spring system as defined in claim 1, including at least a third compression spring, said third compression spring extending between said guide member and said top end of said housing coaxial with said axis. 50. The spring system as defined in 49, wherein a direction of winding of said first and third compression springs is opposite to a direction of winding of said second compression spring. 51. The spring system as defined in claim 49, wherein a length of said first and third compression springs are the same. 52. The spring system as defined in claim 49, wherein outside diameters of said first and third compression springs are less than an outside diameter of said second compression spring. 53. The spring system as defined in claim 49, wherein an outside diameter and wire diameter of said first and third compression springs is less respectively than an outside diameter and wire diameter of said second compression spring. 54. A method of controlling the rate of extension and retraction of a spring rod of a spring system comprising: providing a housing having a longitudinal axis, an internal chamber, and axially opposite bottom and top ends, said spring rod coaxial with said axis and positioned within said internal chamber, said spring rod having an inner end in said housing and an outer end axially outwardly of said top end of said housing, said outer end of said spring rod including a mounting element;providing a guide member positioned on said inner end of said spring rod, said guide member supporting said spring rod for reciprocation axially in said housing between a fully retracted and a fully extended position relative thereto, said guide member dividing said internal chamber into at least upper and lower sub-chambers;providing first and second compression springs each extending between said guide member and the bottom opposite end of said housing, said first and second springs being coaxial with one another and with said axis, at least one of said springs at least partially applying a force on said guide member as said rod member moves between fully retracted and fully extended positions, at least one of said springs having a free length that is at least a majority length of said internal chamber, both of said springs designed to contact said bottom bushing when said rod member in said fully retracted position;providing top and bottom bushings, said top bushing positioned at least closely adjacent to said top end of said housing and said bottom bushing positioned at least closely adjacent to said bottom end of said housing; said top bushing including an opening to enable a portion of said rod member to pass therethrough and to support said rod member for reciprocation axially of said housing between retracted and extended positions relative thereto, said top bushing including a sealing arrangement positioned at least closely adjacent to a bottom of said top bushing to inhibit fluid from entering into and escaping from said internal chamber between said top bushing and said top end of said housing, said guide member designed to move into engagement with or move to a position closely adjacent to said top bushing when said rod member moves to a fully extended position;at least partially controlling the rate of retraction of said spring rod by selecting the spring rate of at least one of said compression springs; and,at least partially controlling the rate of extension of said spring rod by at least partially regulating a fluid flow rate between said sub-chambers, said step of at least partially controlling the rate of extension includes providing a first fluid passageway that passes fully through said guide member, said first passageway fully spaced from an outer edge of said guide member. 55. The method as defined in claim 54, wherein said first passageway at least partially regulates fluid flow between said upper and lower sub-chambers during said extension of said spring rod. 56. The method as defined in claim 55, wherein said first passageway includes a one way valve arrangement. 57. The method as defined in claim 56, wherein said one way valve substantially prevents fluid flow from said upper sub-chamber to said lower sub-chamber during said extension of said spring rod. 58. The method as defined in claim 57, wherein said guide member includes a second passageway, said second passageway fully spaced from an outer edge of said guide member and spaced from said first passageway, said second passageway not in fluid communication with said first passageway. 59. The method as defined in claim 58, wherein said second passageway has a maximum fluid flow rate that is less than a maximum fluid flow rate of said first passageway. 60. The method as defined in claim 59, wherein said bottom end of said housing substantially prevents fluid flow through said bottom end to an exterior of said housing. 61. The method as defined in claim 60, wherein said top end of said housing substantially prevents fluid flow through said top end to an exterior of said housing. 62. The method as defined in claim 61, wherein at least one of said first and second compression springs in a partially compressed state when said spring rod member is in said fully extended position. 63. The method as defined in claim 60, wherein said top end includes a top passageway to allow a controlled rate of fluid flow to exit said upper sub-chamber as said spring member moves to said fully extended position. 64. The method as defined in claim 63, wherein said top passageway is spaced from said spring rod. 65. The method as defined in claim 63, wherein said top passageway is adjacent to said spring rod. 66. The method as defined in claim 58, wherein said second passageway allows for fluid flow in both directions. 67. The method as defined in claim 55, wherein said guide member includes a second passageway, said second passageway fully spaced from an outer edge of said guide member and spaced from said first passageway, said second passageway not in fluid communication with said first passageway. 68. The method as defined in claim 67, wherein said second passageway has a maximum fluid flow rate that is less than a maximum fluid flow rate of said first passageway. 69. The method as defined in claim 68, wherein said second passageway allows for fluid flow in both directions. 70. The method as defined in claim 67, wherein said bottom end of said housing substantially prevents fluid flow through said bottom end to an exterior of said housing. 71. The method as defined in claim 70, wherein said top end of said housing substantially prevents fluid flow through said top end to an exterior of said housing. 72. The method as defined in claim 71, wherein at least one of said first and second compression springs in a partially compressed state when said spring rod member is in said fully extended position. 73. The method as defined in claim 70, wherein said top end includes a top passageway to allow a controlled rate of fluid flow to exit said upper sub-chamber as said spring member moves to said fully extended position. 74. The method as defined in claim 73, wherein said top passageway is spaced from said spring rod. 75. The method as defined in claim 73, wherein said top passageway is adjacent to said spring rod. 76. The method as defined in claim 70, wherein said second passageway allows for fluid flow in both directions. 77. The method as defined in claim 67, wherein said second passageway allows for fluid flow in both directions. 78. The method as defined in claim 54, wherein said bottom end of said housing substantially prevents fluid flow through said bottom end to an exterior of said housing. 79. The method as defined in claim 54, wherein said top end of said housing substantially prevents fluid flow through said top end to an exterior of said housing. 80. The method as defined in claim 54, wherein said top end includes a top passageway to allow a controlled rate of fluid flow to exit said upper sub-chamber as said spring member moves to said fully extended position. 81. The method as defined in claim 80, wherein said top passageway is spaced from said spring rod. 82. The method as defined in claim 80, wherein said top passageway is adjacent to said spring rod. 83. The method defined in claim 54, wherein a direction of winding of said first compression spring is opposite to a direction of winding of said second compression spring. 84. The method as defined in claim 54, wherein a free length of said first compression spring is different from a free length of said second compression spring. 85. The method as defined in claim 54, wherein an outside diameter of said first compression spring is less than an outside diameter of said second compression spring. 86. The method as defined in claim 54, wherein a wire diameter of said first compression spring is less than a wire diameter of said second compression spring. 87. The method as defined in claim 54, including a bushing at said top end of said housing to support said rod for reciprocation axially of said housing between fully retracted and fully extended positions relative thereto. 88. The method as defined in claim 54, including a guide rod that extends from said guide member toward said bottom end coaxial with said axis and said first compression spring surrounds said guide rod. 89. The method as defined in claim 54, including at least a third compression spring, said third compression spring extending between said guide member and said bottom end of said housing coaxial with said axis. 90. The method as defined in claim 54, including at least a third compression spring, said third compression spring extending between said guide member and said top end of said housing coaxial with said axis. 91. The method as defined in claim 90, wherein a direction of winding of said first and third compression springs is opposite to a direction of winding of said second compression spring. 92. The method as defined in claim 90, wherein a length of said first and third compression springs are the same. 93. The method as defined in claim 90, wherein an outside diameter of said first and third compression springs are less than an outside diameter of said second compression spring. 94. The method as defined in claim 90, wherein an outside diameter and wire diameter of said first and third compression springs is less respectively than an outside diameter and wire diameters of said second compression spring. 95. The method as defined in claim 54, wherein at least one of said first and second compression springs in a partially compressed state when said spring rod member is in said fully extended position.