|Publication number||US3851344 A|
|Publication date||Dec 3, 1974|
|Filing date||Mar 16, 1973|
|Priority date||Mar 24, 1972|
|Also published as||DE2312479A1|
|Publication number||US 3851344 A, US 3851344A, US-A-3851344, US3851344 A, US3851344A|
|Original Assignee||E Zeithammer|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (2), Referenced by (7), Classifications (5)|
|External Links: USPTO, USPTO Assignment, Espacenet|
Zeithammer Dec. 3, 1974 FOLDING BED ASSEMBLY  Inventor: Erna Zeithammer, Neustiftgasse Primary Exammer c.asmlr Nunberg 106 Vienna Austria Attorney, Agent, or Fzrml(1nzer, Plyer, Dorn &
McEachran  Filed: Mar. 16, 1973 21 Appl. No.: 342,057 7] ABSTRACT A boxlike covering has a bottom and a vertical rear 0 Foreign Application priority Data wall and is open in front opposite to said rear wall. A
Mar 24 1972 Austria 2549/72 bed has two ends. A horlzontal pivot 15 provided ad acent to one of said ends. The bed is movable about  U S Cl 5/164 D 5/136 said pivot from a horizontal position to a position in [51 1 In} .CI A47; 83/00 said r g T q balancing m an are ged to  Fieid R 164 facilitate the movement of said bed about said pivot 108/2 and comprise a deflecting pulley disposed adjacent to said bottom and in front of said rear wall and spaced  References Cited from the latter, a tension rope connected to said bed and trained around said pulley, and a spring loading UNITED STATES PATENTS said tension rope 3,046,572 7/1962 Eames et al 5/164 R 3,359,927 12/1967 Jonus 103/2 3 Clams, 3 Drawmg Flgures 1H1 ll 2 ll u lillllm FOLDING BED ASSEMBLY This invention relates to a folding bed assembly, which comprises a bed, which is foldable into a boxlike covering about a horizontal pivot disposed adjacent to one end of the bed, said assembly further comprising at least one tension rope, which is connected to the bed and extends around a deflecting pulley disposed adjacent to the bottom of the box and is loaded by springs so that the folding of the bed is facilitated.
A large number of assemblies have been disclosed which comprise a bed that can be folded into a boxlike covering and in which the weight of the bed is compensated in part by tension springs. In most of these beds, the tension springs are connected at one end directly to the bed and at the other end'to the stationary frame of the assembly. Such spring arrangement can compensate only a relatively small part of the weight of the bed so that a relatively large effort is still required to fold the bed up and down.
In a known bed of the kind mentioned first hereinbefore, the deflecting pulley around which the tension rope is trained is disposed adjacent to the rear wall of the box and the stationary frame of the assembly is provided at its end disposed near the head end of the bed with a cam track, in which the tension rope is guided, which is loaded by a counterweight or by spring means. In such an arrangement, the bed may assume an intermediate position in which the torques which are due to the spring force and to the weight of the bed, respectively, balance each other. In the other intermediate positions, either the torque which is due to the weight of the bed or the torque which is due to the spring force will predominate. In spite of the relatively complicated provision of a cam track the weight of the bed is compensated only in part in this known arrangement and its manipulation also requires a relatively large effort.
It is an object of the invention to provide an assembly which is of the kind described first hereinbefore and in which the weight of the bed is virtually compensated in any possible intermediate position. This object is accomplished in that the deflecting pulley is disposed in front of and spaced from the rear wall of the box. As a result of this simple measure taught by the invention, the weight of the bed, the spring force and the lever arms can be selected so that the torques due to spring force and load, respectively, balance each other in all positions of the bed and substantially no effort is required to manipulate the bed.
Whereas it has already been disclosed in connection with power-operated folding beds to provide a deflecting pulley which is disposed in front of and spaced from the rear wall of the box, that arrangement of the pulley in the known assemblies is necessitated by the arrangement of the motor and does not result in a balancing of torques.
To reduce the space requirement in spite of the fact that the deflecting pulley is disposed in front, on the one hand, and to avoid the use of very strong springs, on the other hand, a further feature of the invention resides in that the tension rope extends from the deflecting pulley, which is disposed in front of and spaced from the rear wall of the box, to another deflecting pulley disposed adjacent to the rear wall of the box, further around a movable pulley, which is connected to the spring, to stationary rope-fixing means disposed adjacent to the bottom of the box.
It will also be desirable within the scope of the invention if two tension ropes are provided on opposite sides of the bed and each of the two movable pulleys is secured to a cross-member, which is'provided with two tension springs. In that case, a dropping'of the bed will be reliably avoided even in case of a breakage of one spring.
The invention will now be explained more fully with reference to an embodiment shown by way of example in'the drawings but is not restricted to this embodiment.
FIG. 1 is a side elevation showing a bed assembly according to the invention in solid lines in an upfolded position and in dotted lines in a downfolded position.
FIG. 2 is an elevation showing one-half of the bed assembly as viewed in the direction of arrow II in FIG. 1.
FIG. 3 shows the bed assembly in an intermediate position to illustrate the torque actions.
The drawings show a bed 1 which is foldable about an axis 2 which is defined in that pivot pins mounted on the side members of the bed are seated in recesses formed in arms 3. The arms 3 form parts of a frame 4. Two pairs of tension springs 5 are hooked into the top member of the frame 4 near respective ends thereof. Each pair of tension springs carry a cross-member 6, to which a pulley 7 is connected. A plate 9 is connected by struts 8 to the frame 4. Two deflecting pulleys 10 and 11 are mounted on the plate 9. The pulley 10 is spaced from the frame 4, which forms also the rear wall of a boxlike covering. The side walls of the covering are desirably connected to the arms 3.
A tension rope 13 is connected to an arm 12, which is connected in turn to the end of the bed 1. The rope 13 is trained around the deflecting pulleys l0 and 11 and the floating pulley 7 and extends to a fixing point 14 on the frame 4.
It is apparent from FIG. 3 that a perfect torque balance will be accomplished when the product of the rope force S times its lever arm a equals the product of the force due to the weight G times its lever arm b. The rope force can be determined with the aid of the spring characteristic from the force of the spring at the spring excursion f with an allowance for the efficiency of the pulleys. Calculations for different intermediate positions of the bed and practical experiments have shown that there is a torque balance in all positions.
What is claimed is:
1. A folding bed assembly, which comprises a boxlike covering which has a bottom and a vertical rear wall and is open in front opposite to said rear wall,
a bed having two ends,
means defining a horizontal pivot adjacent to one of said ends, said bed being movable about said pivot from a horizontal position to a position in said covering, and
torque-balancing means arranged to facilitate the movement of said bed about said pivot and comprising a deflecting pulley disposed adjacent to said bottom and in front of said rear wall and spaced from the latter, a tension rope connected to said bed and trained around said pulley, and a spring loading said tension rope.
2. An assembly as set forth in claim 1, in which 3 4 said torque-balancing means further comprise rope- 3. An assembly as set forth in claim 2, in which fixing means disposed adjacent to said bottom, an 'said bed has two sides, additional deflecting pulley disposed adjacent to said torque-balancing means are provided on one of said rear wall, and a floating pulley connected to said sides of said bed and comprise an additional said spring, and 5 spring loading said rope and a cross-member to said tension rope extends from said bed around said which said springs and said floating pulley are confirst-mentioned deflecting pulley, said additional nected, and deflecting pulley and said floating pulley, in that similar torque-balancing means are provided on the order, to said ropefixing means and is fixed to the other of said sides of said bed. latter. 0
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|Citing Patent||Filing date||Publication date||Applicant||Title|
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|US5207110 *||Mar 28, 1991||May 4, 1993||The United States Of America As Represented By The United States National Aeronautics And Space Administration||Suspension device for low-frequency structures|
|US5353452 *||Sep 8, 1993||Oct 11, 1994||Rulis Robert A||Folding bed assembly|
|US5446932 *||May 18, 1994||Sep 5, 1995||Voorhis; Donald P.||Folding wall bed|
|US5875502 *||Jan 14, 1998||Mar 2, 1999||Kolbenstetter; Gary||Space saving institutional bed|
|U.S. Classification||5/164.1, 5/136|