Slip nut assembly for adjustable height bed
View Patent ↗An adjustable bed includes a universal, or interchangeable, bed end that can be used at either end of the bed and that can be connected with a motor drive assembly. The bed end may include a manual crank that is removably attached to the bed end. The bed end may include an elevating mechanism that includes a cross-beam or similar structure for transmitting motive force between fixed and movable portions of the bed end. The bed end may also include a new slip nut assembly for transmitting motive force from a lead screw. The bed may further include a reversible corner plate for allowing the bed end to be used facing in either direction. The bed end may also include a plastic cover that is washable and scratch resistant.
1. A bed end for a bed having a patient support that is adjustable vertically relative to a floor on which the bed is placed, said bed end comprising:
a lead screw rotatable in first and second opposite directions of rotation to effect raising and lowering of a movable portion of said bed end;
a slip nut assembly for transmitting vertical force from said lead screw to said movable portion of the bed to adjust the patient support vertically;
said slip nut assembly including a slip nut threadedly engaged with said lead screw, said slip nut being formed in two pieces;
said slip nut having a first condition in which it is fixed against rotation within said movable portion of said bed thereby to transmit vertical force from said lead screw to said movable portion of the bed when said lead screw rotates;
said slip nut having a second condition in which it is rotatable within said movable portion of said bed with said lead screw thereby to block transmission of vertical force from said lead screw to said movable portion of the bed;
said slip nut assembly including first and second leaf springs and pressure plates operative to bias said slip nut into engagement with said lead screw; and
wherein each one of said leaf springs has opposite end portions engaged in recesses in said pressure plates.
2. A bed end as set forth in claim 1 wherein said pressure plates comprise first and second pressure plates engageable with said slip nut, said leaf springs biasing said pressure plates into engagement with said slip nut.
3. A bed end as set forth in claim 2 wherein said each one of said slip nut pieces has an arcuate configuration extending about 180 degrees and each one of said leaf springs has an arcuate configuration extending about 180 degrees about said slip nut.
4. A bed end as set forth in claim 1 wherein said two pieces of said slip nut are identical to each other.
5. A bed end as set forth in claim 4 wherein each one of said two pieces of said slip nut has an axially extending portion for engagement with a radially projecting portion of said lead screw, said axially extending portions of said two slip nut pieces extending in opposite axial directions.
6. A bed end as set forth in claim 1 wherein said first and second leaf springs are self-supporting on said slip nut assembly.
7. A bed end for a bed having a patient support that is adjustable vertically relative to a floor on which the bed is placed, said bed end comprising:
a lead screw rotatable in first and second opposite directions of rotation to effect raising and lowering of a movable portion of said bed end;
a slip nut assembly for transmitting vertical force from said lead screw to said movable portion of the bed to adjust the patient support vertically;
said slip nut assembly including a slip nut threadedly engaged with said lead screw, said slip nut being formed in two pieces;
said slip nut having a first condition in which it is fixed against rotation within said movable portion of said bed thereby to transmit vertical force from said lead screw to said movable portion of the bed when said lead screw rotates;
said slip nut having a second condition in which it is rotatable within said movable portion of said bed with said lead screw thereby to block transmission of vertical force from said lead screw to said movable portion of the bed;
said slip nut assembly including first and second leaf springs and pressure plates operative to bias said slip nut into engagement with said lead screw; and
wherein said first and second leaf springs are exposed on their exterior, having no portion being forced radially inward against said pressure plates.
8. A bed end for a bed having a patient support that is adjustable vertically relative to a floor on which the bed is placed, said bed end comprising:
a lead screw rotatable in first and second opposite directions of rotation to effect raising and lowering of a movable portion of said bed end;
a slip nut assembly for transmitting vertical force from said lead screw to said movable portion of the bed to adjust the patient support vertically;
said slip nut assembly including a slip nut threadedly engaged with said lead screw;
said slip nut having a first condition in which it is fixed against rotation within said movable portion of said bed thereby to transmit vertical force from said lead screw to said movable portion of the bed when said lead screw rotates;
said slip nut having a second condition in which it is rotatable within said movable portion of said bed with said lead screw thereby to block transmission of vertical force from said lead screw to said movable portion of the bed;
said slip nut assembly including first and second leaf springs operative to inhibit rotation of the slip nut upon rotation of said lead screw; and
a driveshaft that is rotatable in first and second opposite directions of rotation about a first axis to raise and lower said movable portion of said bed end, said lead screw being rotatable about a second axis transverse to said first axis, said bed end further comprising a gearbox connected with said lead screw for transmitting rotational force from the driveshaft to said lead screw;
wherein said gearbox can be coupled with the driveshaft in a first condition receiving rotational force from the driveshaft in a first direction of rotation about said first axis and effecting rotation of said lead screw about said second axis in a direction so as to raise said movable portion of said bed end; and
wherein said gearbox can be coupled with said driveshaft in a second condition receiving rotational force from the driveshaft in said first direction of rotation about said first axis and effecting rotation of said lead screw about said second axis in a direction so as to lower said movable portion of said bed end.
9. A bed end as set forth in claim 8 wherein said gearbox includes first and second input shafts, said first input shaft being coupled with the driveshaft when said gearbox is in the first condition and said second input shaft being coupled with the driveshaft when said gearbox is in the first condition.
10. A bed end as set forth in claim 8 wherein said gearbox has an input shaft that is selectively movable in a housing between first and second positions relative to said housing, said input shaft being in the first position when said gearbox is in the first condition and said input shaft being in the second position when said gearbox is in the second condition.
11. A bed end as set forth in claim 10 wherein said input shaft includes first and second gears spaced along said input shaft and movable into and out of engagement with an output gear in response to movement of said input shaft between the first and second positions.