Vertically adjustable overbed table

• US 3,890,907 A
• Filed: 10/24/1973
• Issued: 06/24/1975
• Est. Priority Date: 10/24/1973
• Status: Expired due to Term

• Current Assignee: Joerns Healthcare, Inc. (Joerns Healthcare LLC)
• Original Assignee: Warren J. Peterson
• Inventors: Peterson, Warren J.
• Primary Examiner(s): Parsons, Jr., Marion
• Assistant Examiner(s): Marquette, Darrell
• Application Number:
  US05/409,360
• Time in Patent Office: 608 Days
• Field of Search: 108/146,144,136 248/162,412,337,336
• US Class Current: 108/136
• CPC Class Codes: A47B 2023/047 with pivoting top plate
• CPC Class Codes: A47B 23/046 C-shaped bed tables, e.g. foldable
• CPC Class Codes: A47B 9/02 with balancing device, e.g. by springs, by weight

Abstract

A vertically adjustable overbed table including a pedestal, a horizontal table top mounted at the top of the pedestal and a horizontal roller-equipped base platform at the lower end of the pedestal. The pedestal includes an upper outer column which telescopes over a lower inner column, and a pair of constant force springs which are mounted within the columns to maintain the telescoping columns in equilibrium. A clutch assembly is mounted within the top of the upper column which includes a rotatable clutch drum, a clutch spring around the clutch drum and a rotatable spool wound with cable, the spool being connected to the clutch drum so that both rotate together. A depending loop is formed at an intermediate portion of the table which engages a pulley wheel at the lower end of a vertical shaft extending below the clutch assembly within the columns. One point of the depending cable is rigidly affixed to the inner column so that the two columns can be moved telescopically only when the cable spool is free to rotate to pay out and take up equal amounts of cable. Lever means are provided for releasing the tension on the clutch spring so that the clutch drum and the spool are free to rotate so that the table can be lowered. An override assembly is also provided in conjunction with the clutch spring which releases the clutch spring tension when a sufficient downward force is placed on the table top so that the table top can be lowered without utilizing the tension releasing lever means. The table top can be raised by exerting an upward force on the table top sufficient to overcome the equilibrium effect of the constant force spring.

Claims

1. A vertically adjustable overbed table comprising:

a pedestal, a horizontal table top mounted at the top of said pedestal and a base platform at the lower end of said pedestal;

said pedestal including an outer column and an inner column, said outer column telescopically engaging said inner column and being adapted for vertical telescoping movement with respect to said inner column;

at least one spring means associated with said columns for maintaining the telescoping movement of said outer column and said inner column in approximate equilibrium; and

a clutch assembly mounted within said pedestal;

said clutch assembly including a rotatable clutch drum, means for rotating said drum during telescopic movement of said columns, a tensioned clutch spring means surrounding said drum for permitting upward movement of one of said columns with respect to the other of said columns when an upward force is exerted thereon sufficient to overcome the equilibrium effect of said constant force spring and for permitting downward movement of said one column with respect to said other column only when the tension of said clutch spring is released; and

means for releasing the tension of said clutch spring.

2. The overbed table according to claim 1 wherein said outer column is affixed to said table top, wherein said inner column is affixed to said base and wherein said clutch assembly is mounted within said outer column and comprises a horizontally mounted rotatable clutch drum;

a tensioned helical coil spring around said drum;

a horizontally mounted rotatable cable spool adjacent said clutch drum and connected thereto so as to be rotatable therewith and only therewith;

a cable having its ends wound around said spool in opposite directions, the ends of said cable being affixed to said spool and an intermediate portion of said cable extending below said spool to form a depending cable loop and an intermediate point of said cable loop being affixed to said inner column;

a rigid member depending within said columns and attached at its upper end to an upper portion of said outer column and having a pulley wheel at the lower end thereof receiving said depending cable loop, whereby said outer column can be telescoped downwardly over said inner column when a downward force is placed on said outer column only when said clutch spring tension is released and said spool is free to rotate to take up cable above said intermediate point of said depending cable loop and to pay out an equal amount of cable below said intermediate point of said depending cable loop.

3. The overbed table according to claim 2 wherein one end of said clutch spring extends outwardly from said spring coil and wherein said means for releasing the tension on said clutch spring comprises a trip plate reciprocally mounted on said outer column;

said trip plate having a finger-like extension in engagement with said one end of said clutch spring so that when said trip plate is moved in a first direction said clutch spring tension is released so said table top can be lowered.

4. The overbed table according to claim 3 wherein at least one upwardly spring-biased lever arm is pivotally mounted on said outer column adjacent said trip plate and in engagement therewith so that when said lever arm is depressed downwardly said trip plate will release the clutch spring tension.

5. The overbed table according to claim 4 which includes a pair of said lEver arms each extending outwardly from said outer column to opposite sides of said table top.

6. The overbed table of claim 4 wherein said spring means includes a pair of said constant force springs;

each of said constant force springs comprising a leaf spring rolled around an axle, each said constant force spring having one end affixed to the lower end of said rigid member and having its axle horizontally rotatably mounted at an upper portion of said inner column.

7. The overbed table according to claim 6 which further comprises a spring-biased override assembly mounted on said outer column adjacent said clutch assembly in engagement with the other end of said clutch spring whereby when a downward force is exerted on said outer column sufficient to overcome the spring biasing of said override assembly, said override assembly will release the clutch spring tension so that said table top can be lowered.

8. The overbed table of claim 7 wherein movement of said one end of said clutch spring is in a direction opposite to said first direction is restricted by said finger-like extension, wherein the other end of said clutch spring depends away from said clutch spring coil and wherein said override assembly comprises an override lever rotatably mounted adjacent said other end of said clutch spring having a foot in engagement with said other end of said clutch spring;

said override lever being spring biased against rotation in a direction in which said foot will tend to be moved by said other end of said clutch spring when a downward force is exerted on said outer column whereby when a downward force is exerted on said outer column sufficient to overcome the spring-biasing of said override lever, said override lever will be rotated by said other end of said clutch spring and the clutch spring tension will thereby be released to permit said table top to be lowered.

9. The table as set forth in claim 2 wherein said spool includes two abutting sections, one section being rotatable with respect to the other to wind cable thereon during assembly of said table.

10. The table as set forth in claim 9 wherein said spool sections have ratchet faces in abutment with one another permitting one section to be rotated with respect to the other in a non-working direction only to wind cable thereon during assembly of said table.

11. The table as set forth in claim 10 which further comprises means for resiliently urging said faces together.

12. A vertically adjustable overbed table comprising:

a pedestal, a horizontal table top mounted at the top of said pedestal and a base platform at the lower end of said pedestal;

said pedestal including an outer column and an inner column, said outer column telescopically engaging said inner column and being adapted for vertical telescoping movement with respect to said inner column; and

a clutch assembly mounted within said pedestal for controlling the telescoping movement of said columns;

said clutch assembly including a rotatable clutch drum, means for rotating said drum during telescopic movement of said columns, a tensioned clutch spring means for selectively restraining rotation of said drum, said spring means permitting free rotation of said drum in a first direction to permit free upward movement of one of said columns with respect to the other of said columns when an upward force is exerted thereon, said spring means restraining rotation of said drum in a direction opposite to said first direction to restrain downward movement of said one column with respect to said other column; and

means for releasing the tension on said clutch spring to permit free rotation of said drum in said opposite direction.

13. The overbed table according to claim 12 wherein said outer column is affixed to said table top, wherein said inner column is affixed to said base and wherein said clutch assembly is mounted within said outer column and comprises a horizontally mounted rotatable clutch drum;

a tensioned helically coiled spring positIoned around said drum, said spring having one end thereof arrested from movement and being positioned around said drum such that the spring tends to tighten radially under the influence of attempted rotation of said drum in said opposite direction, a horizontally mounted rotatable cable spool adjacent said clutch drum and connected thereto so as to be rotatable therewith and only therewith;

a cable having its ends wound around said spool in opposite directions, the ends of said cable being affixed to said spool and an intermediate portion of said cable extending below said spool to form a depending cable loop and an intermediate point of said cable loop being affixed to said inner column;

a rigid member depending within said columns and attached at its upper end to an upper portion of said outer column and having a pulley wheel at the lower end thereof receiving said depending cable loop, whereby said outer column can be telescoped downwardly over said inner column when a downward force is placed on said outer column only when said clutch spring tension is released and said spool is free to rotate to take up cable above said intermediate point of said depending cable loop and to pay out an equal amount of cable below said intermediate point of said depending cable loop.

14. The table as set forth in claim 12 wherein said releasing means comprises a lever which is moveable downwardly to release the tension of said clutch spring.