Seat suspension assembly

• US 5,735,509 A
• Filed: 02/08/1996
• Issued: 04/07/1998
• Est. Priority Date: 02/08/1996
• Status: Expired due to Fees

• Current Assignee: Sears Manufacturing Co.
• Original Assignee: Sears Manufacturing Co.
• Inventors: Gryp, Dennis J., Toomey, Mark H.
• Primary Examiner(s): Butler, Douglas C.
• Application Number:
  US08/597,435
• Time in Patent Office: 789 Days
• Field of Search: 267/131, 267/117, 267/113, 297/344.16, 248/550, 248/631, 248/421, 248/575, 248/592, 248/598, 248/425, 296/65.1
• US Class Current: 267/131
• CPC Class Codes: B60N 2/501 actively controlled suspension, e.g. electronic control
• CPC Class Codes: B60N 2/502 attached to the base of the seat B60N2/504 takes precedence
• CPC Class Codes: B60N 2/505 Adjustable suspension including height adjustment
• CPC Class Codes: B60N 2/508 Scissors-like structure
• CPC Class Codes: B60N 2/525 using gas

Abstract

A pneumatic seat suspension assembly including upper and lower support members with scissors linkages extending therebetween, a pneumatic spring operatively attached between one set of opposing parallel scissors arms, a height adjuster in communication with the pneumatic spring, a dump valve in communication with the pneumatic spring and a safety rollover valve in communication with the pneumatic spring. The scissors linkage provides the mechanical connection between the seat bottom and the seat support while the pneumatic spring provides the structure to raise and lower the seat bottom by use of compressed air which causes the parallel scissors linkages to be pushed upward causing the seat to rise. The height adjuster consists of an air valve connected via air lines to the pneumatic spring and to a valve to transmit or vent pressurized air to or from the spring to allow the seat to be biased vertically within a range while the pressurized air within the air spring compensates for the weight of the seat occupant. The dump valve provides a trigger which, when actuated, releases the air from the pneumatic suspension assembly to lower the seat to its lowest point to allow easy access to the seat such that when re-activated allows for the seat to regain its pre-dump position. The rollover valve is connected along the main air line to the pneumatic spring such that, when the plane of the seat bottom reaches approximately 80° from the horizontal, the air in the pneumatic spring is released allowing for the seat bottom to descend to its lowest position.

Claims

1. In a vehicle seat suspension system comprising a linkage assembly having first and second pairs of linkage arms, an upper support and a lower support, an air spring operatively communicating with the linkage assembly, and a suspension adjustment lever, the improvement comprising:

a pneumatic height adjuster valve adapted to allow the upper support to travel vertically within a predetermined range, said valve being in pneumatic communication with an air source and with the air spring and being coupled to one of the first pair of linkage arms, and a connection assembly operatively connected to one arm of the second pair of linkage arms configured to allow the pneumatic height adjuster valve to respond to movement of the upper support;

a dump valve in pneumatic communication with the air spring and having an actuator that permits the release of air from the air spring, to thereby allow the upper support to descend to its lowest position; and

a rollover valve in pneumatic communication with the air spring to permit the automatic release of air from the air spring when the angle between the plane of the upper support and horizontal reaches a predetermined value.

2. The vehicle seat suspension system of claim 1 further comprising a shock absorber pivotally connected to the linkage assembly to dampen vertical travel of the upper support.

3. In a vehicle seat suspension system comprising a linkage assembly, an upper support and a lower support, a pneumatic air spring, and a suspension adjustment lever, the improvement comprising:

means for preventing the upper support from traveling outside a given range;

means for causing the upper support to travel to its lower most position relative to the lower support independently of the suspension adjustment lever; and

means for automatically allowing the upper support to travel to its lowermost position relative to the lower support when the angle between the plane of the upper support and horizontal reaches a predetermined value.

4. The vehicle seat suspension system of claim 3 further comprising means for damping vertical travel of the upper support.

5. In a vehicle seat suspension system comprising a linkage assembly having first and second pairs of linkage arms, an upper support and a lower support, an air spring operatively communicating with the linkage assembly, and a height adjustment lever, the improvement comprising:

a pneumatic control valve adapted to allow the upper support to travel vertically within a predetermined range, said valve being in pneumatic communication with an air source and with the air spring and being coupled to one arm of the first pair of linkage arms;

a connection assembly secured to said other arm of the first pair of linkage arms and communicating with the pneumatic control valve responsive to an angular change between said first and second arms;

wherein the height adjustment lever is manually operable to cause the valve to adjust the height of the upper support to attain an equilibrium height, and the connection assembly causes the valve to automatically respond to said angular change to maintain the equilibrium height of the seat.

6. The suspension assembly of claim 5 wherein the valve includes a rotating shaft for regulating air flow to the air spring based on an angle θ

between the valve and the shaft and the connection assembly comprises;

a bracket secured to said other arm of the first pair of linkage arms and having a spindle having at least one height adjust arm and a weight adjust arm communicating with said valve shaft attached thereto and said height adjust lever communicating with said at least one height adjust arm whereby the lever is manually operable to rotate the spindle to define an angle θ

setting an equilibrium height of the upper support.

7. An air suspension system for a seat having independent height adjustment and weight adjustment comprising:

a base;

an upper support mechanically connected to the base and adapted to travel vertically with respect to the base;

an air spring adapted between the base and upper support to cause the upper support to travel vertically relative to the base;

a height adjust valve in pneumatic communication with the air spring and operably responsive to movement of the upper support relative to the base;

a dump valve in pneumatic communication with the air spring and having an actuator permitting the release of air from the air spring to allow the upper support to descend to a lowermost position relative to the base;

a safety valve in pneumatic communication with the air spring to permit the automatic release of air from the air spring when the angle between the plane of the upper support and horizontal reaches a predetermined valve; and

a source of pressurized air operably communicating with the air spring, the height adjust valve, the dump valve and the safety valve via a single conduit;

whereby the height adjust valve can be manually adjusted to establish a neutral height of the upper support relative to the base and automatically maintains the established neutral height.

8. The suspension system of claim 7 wherein the height adjust valve includes a rotating shaft for regulating air flow to the air spring based on an angle θ

between the valve and the shaft and the upper support is mechanically connected to the base via a linkage assembly including at least one pair of linkage arms, and further comprising a connection assembly which comprises;

a bracket secured to one arm of the at least one pair of linkage arms and having a spindle having at least one height adjust arm and a weight adjust arm communicating with said valve shaft attached thereto and a height adjust lever communicating with said at least one height adjust arm whereby the lever is manually operable to rotate the spindle to define an angle θ

setting a neutral height of the upper support.