US3290700A

US3290700A - Lift leg structure

Info

Publication number: US3290700A
Application number: US519488A
Authority: US
Inventors: Chester J Barecki; Robert L Knapp
Original assignee: American Seating Co
Current assignee: American Seating Co
Priority date: 1966-01-10
Filing date: 1966-01-10
Publication date: 1966-12-13
Anticipated expiration: 1983-12-13

Description

Dec. 13, 1966 1.BAREc| ETAL 3,290,700

LIFT LEG STRUCTURE 5 Sheets-Sheet 1 Filed Jan. 10, 1966 5 5 00 Q0 4\ 3 3 I-.. 2 I 1 w "3 2 w m m FIG. 3-

INVENTOR Chester J. Burecki Robert L. Knapp @awuow, Jlfmu, 70%122, 6

WITNESS ,alwfivllbumdwu ATTORNEY FIG. 5

Dec. 13, 1966 c. J. BARECKl ET AL 3,290,700

LIFT LEG STRUCTURE 5 Sheets-Sheet 2 Filed Jan. 10, 1966 R m. M m m O 7 w 1 n o e a A ?u u m um N am 4 F 2 O J J m 67 33 F Q Va n m I s CRQE 3 Y 4 B VI 2 -l\ J n7 C" T 5 1/: 31 2 Q: \.I Q" m m m n PB J. 4 E Hun 97 l- [A 2L -1 W Dec. 13, 1956 c BARECKl ET AL 3,290,790 7 LIFT LEG STRUCTURE Filed Jan. 10, 1966 5 Sheets-Sheet 3 IA F56. i6

INVENTOR Chester J. Barecki Weber? L. Knapp WITNESS BY w mu J/lfimv, 1 11112111,

United States Patent Filed Jan. 10, 1966, Ser. No. 519,488 6 Claims. (Cl. -63) This invention relates to a lift leg structure, and is particularly useful in connection with a leg for lifting and lowering a hospital bed section. For the purpose of illustration, the invention will be described herein as a leg structure for a hospital bed.

An object of the present invention is to provide a lift leg structure which improves the lifting and lowering operation of a member such as, for example, a hospital bed section. A further object is to provide in such a lift leg structure a sheave or pulley wheel structure in which the sheave serves also as a guide while keeping the lifting or tension element close to the center of the inner or fixed leg. A still further object is to provide in such a structure a leg cylinder formed as an extrusion casting and providing locking or holding elements for the anchor cap and caster stem. A still further object is to provide a' unique inner leg structure and a cooperating outer leg or sleeve with sheave slots which eliminate the need for rightor left-hand leg brackets. Other specific objects and advantages will appear as the specification proceeds.

The invention is shown in illustrative embodiments, by the accompanying drawings, in Which- FIG. 1 is a perspective view of a hospital bed of the electrically-operated type equipped with push button controls; FIG. 2, a perspective view of a similar bed which is however manually-operated and is equipped with hand-operated cranks; FIG. 3, a top plan view of a typical bed frame adapted to be used with either of the beds shown in FIGS. 1 and 2 and in which tension elements (partially broken away) are shown for operating the lift leg structure; FIG. 4, a side view in elevation of the structure shown in FIG. 2 and with the bed section shown in elevated position; FIG. 5, a view similar to FIG. 4 but showing the bed section in lowered position; FIG. 6, a broken top plan view of a portion of the bed section equipped with a leg assembly embodying our invention; FIG. 7, a partial vertical section of the structure shown in FIG. 6, the section being taken as indicated at line 7-7 of FIGS. 6 and 9; FIG. 8, a broken side view in elevation, the view being taken as indicated at line 8-8 of FIG. 6; FIG. 9, a transverse sectional view, the section being taken as indicated at line 9--9 of FIG. 7; FIG. 10, a side view in elevation of the lift leg structure on a reduced scale but showing the bed section in lowered position and also showing the bed section in phantom lines in elevated position; FIG. 11, a broken top plan view of the bed section equipped with a modified form of lift leg structure in which the outer leg or sleeve is provided with two slots, thus eliminating the need for rightor left-hand leg brackets, the leg being on the right side of the bed; FIG. 12, a view similar to FIG. 11 but showing the lift leg structure on the left side of the bed; FIG. 13, a sectional view, the section being taken as indicated at line 13-13 of FIG. 11; FIG. 14, a side view in elevation, the view being taken as indicated at line 14-14 of FIG. 11; FIG. 15, a transverse sectional view, the section being taken as indicated at line -15 of FIG. 14 and FIG. 16; and FIG. 16, a detail sectional view, the section being taken as indicated at line 1616 of FIG. 15.

In the illustration given in FIGS. 110 inclusive, A indicates a manually-operated hospital bed and A an 3,299,700 Patented Dec. 13, 1966 electrically-operated hospital bed. In the operation of either form of bed for lifting and lowering the bed section, it is common to employ a tension element 10 for lifting or lowering one end of the bed and tension elements 11 for lifting the other end of the bed. Tension element 10 engages a draw bar 12 to which are secured two cables or

tension elements

13 and 14. These extend around

inclined sheaves

15 and 16 and operate the lift bed structure at the corners of one end of the bed. Similarly, the lift elements 11 pass around

inclined pulley wheels

17 and 18 and operate the lift leg structures at the other end of the bed. Since such structures are well known, a detailed description herein is believed unnecessary. In practice, an actuating bar manipulates both the tension element 10 and the tension elements 11 and such a bar may be manually operated or operated by an electric motor.

As shown best in FIGS. 4 and 5, the bed structure 19 is supported upon inner legs 20 and is arranged to move upwardly and downwardly on the inner legs 20, the bed 19 being shown in elevated position in FIG. 4 and in lowered position in FIG. 5.

The lift leg structure is shown in detail in FIGS. 610 inclusive. At the corner of the bed, as shown best in FIG. 6, the bed frame is provided with a bed side angle member 21 and a cross angle member 22. Suspended from the two angle members is a bracket member 23 which extends downwardly and is provided at its lower end with a sleeve or outer leg 24.

Spacer members

25 and 26 are provided for supporting the bracket 23, as shown best in FIGS. 7 and 8.

The sleeve member or outer leg member 24-, as shown best in FIG. 9, is provided with a slotway 27 for receiving a sheave or pulley wheel 28, and a sheave pin 29 extends across the slotway and is-held by roll pins 30. A tension element, which is desginated as element 11 but which may 'be any of the tension elements shown in FIG. 3, as, for example,

elements

13 and 14, extends around the sheave 28 and is secured to the upper end of the inner leg ,20.

The inner leg 20 may be formed in any suitable manner and of any suitable material. We prefer to form it of aluminum or aluminum alloy and to extrude the same in the shape and form illustrated in FIGS. 7, 8 and 9. The portion of the cylinder near the sheave 28 is provided with a deep groove 31 to receive the inner portion of the sheave and thus bring the tension element 11 close to the center or vertical axis of the inner leg 20. Also, the cylinder is provided with radial webs 32 which extend inwardly and merge with a ring member 33. The ring 33 is provided at its top. with threads for receiving a screw 34 which holds the anchor cap 35 in position on the top of the cylinder 20. At the bottom of the cylinder or inner leg 20, there is received the crown 36 of the anti-friction race mounted on the bracket 37 of the caster 38, and the ring 33 receives the stem 39 of the caster. Thus the ring 33 serves at its upper end for securing the anchor cap in place, while at its lower end it receives and supports the stem or pin of the caster member, as shown best in FIG. 9.

Any suitable bearings may be provided between the sleeve or upper leg member 24 and the inner leg or cylinder 20. As shown best in FIG. 6, we provide bearings 40 and 41 at the top portion of the member 24 and bear

ings

42 and 43 at the lower portion of the member 24.

In the lower portion of the inner leg 20 are stop screws 44 having hexagonal heads and limiting the downward movement of the member 24. If desired, a single stop 44 will suffice for limiting such movement.

The tension element 11, as shown best in FIG. 8, is provided at its upper end with a threaded portion 45 which extends through and is secured by a nut 46, as

shown best in FIG. 8.

Operation In the operation of the structure shown in FIGS. 1-10 inclusive, when the outer leg or sleeve 24 is in lowered position, as illustrated in FIG. 10, and when the ten sion element 11 is drawn inwardly, this causes the sheave 28 together with the outer sleeve or leg 24 to move upwardly along the fixed leg 20 to the raised position shown in dotted lines in FIG. 10. Similarly, when the cable or tension member 11 is slackened, the weight of the bed section causes the outer leg 24 to drop to the lower position shown in solid lines in FIG. 10. In these operations, the pulley or sheave 28 holds the tension element inwardly close to the vertical axis of the inner leg 20 while at the same time the sheave itself serves as a key or guide to cause vertical movement of the sleeve and bed section along inner leg 20. In these operations, the central ring 33 of the inner leg casting serves to hold the screw 34 in position and the anchor .33 in its lower end receives and holds the stem 39 of the caster.

In the modification illustrated in FIGS. 1116 inclusive, the lift leg structure is substantially the same as that described in FIGS. 110 inclusive except that the outer leg or sleeve 24a is provided with two slots 27a for alternately receiving the sheave 28a, thus eliminating the need for rightor left-hand leg brackets. FIG. 11 shows the bracket structure on one side of the bed, while FIG. 12 shows the structure on the other side of the bed.

To change the leg assembly from right-handed to left-handed, it is merely necessary to remove one of the roll pins 30a, withdraw the sheave pin 29a, remove the sheave 28a, and rotate the inner leg 20a until the groove 31a is aligned with the right-hand slot of the outer leg. Then the sheave, sheave pin and roll pin are inserted to secure the sheave in the new slot.

In the structure shown in FIGS 11-16 inclusive, we provide the inner leg 20a with a slight tip or projection 47 which keeps the plastic bearing 48 from turning. The one-piece bearing 48 is shown in detail in FIG. 16.

The operation of the structure shown in FIGS. 11-16 is in other respects the same as that described for the structure shown in FIG. 1-10, the tension element 11a extending about the sheave 28a and being held against the anchor cap a by the nut 46a, the outer leg and the bed section being raised as the tension element 11a is drawn and being lowered as the tension element is slackened.

While in the foregoing specification we have set out structure in considerable detail for the purpose of illustrating embodiments of the invention, it will be under- 4. stood that such details may be varied widely by those skilled in the art without departing from the spirit of our invention.

We claim:

1. In a lift device, telescoping inner and outer cylindrical legs, said inner leg being adapted to rest upon the floor and having a vertical portion thereof turned inwardly to provide a grooved keyway bearing, said outer leg being fixed to a member to be lifted and provided with a slot and with radially-extending flanges providing a sheave bearing, a sheave between said flanges, a transverse sheave pin extending through said flanges and sheave, said sheave extending into said keyway for engagement therewith as a key, and a tension element extending about said sheave and within said keyway and having its end fixed to an upper portion of said inner leg.

2. The structure of claim 1 in which said sheave has its peripheral portion recessed to receive said tension element and has laterally-extending peripheral bearing surfaces for engagement with said keyway bearing.

3. The structure of claim 2 in which said peripheral bearing surfaces have portions projecting outwardly from the cylindrical leg and adjacent the peripheral bearing surfaces of said sheave.

4. The structure of claim 1 in which said outer leg is provided with two pairs of radially-extending sheavesupporting flanges, said pairs of flanges extending sub-- stantially at right angles to each other.

5. The structure of claim I in which said inner leg is provided with a central integral ring having radial webs connecting it to the cylindrical wall of the inner leg and having one web connecting said ring to said keyway bearing.

6. In a hospital bed, a bed section equipped at four sides with telescoping inner and outer cylindrical legs, said inner legs having their lower ends adapted to rest upon the floor and each being provided with an in Wardly-turned vertical portion providing a grooved keyway bearing and each of said outer legs being provided with a transverse slot equipped with a sheave pin, a sheave within each of the slots and carried by said sheave pin with the inner end of the sheave extending into said keyway for engagement therewith as a key, and a tension element extending about said sheave and secured to the top portion of said inner leg.

References Cited by the Examiner UNITED STATES PATENTS 2,872,688 2/1959 Reichert et al. 553 3,132,351 5/1964 Huntress et a1. 5-63 3,217,339 11/1965 Black et a1. 5-63 FRANK B. SHERRY, Primary Examiner.

CASMIR A. NUNBERG, Assistant Examiner.