CA1196736A - Spring unit - Google Patents

Spring unit

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Publication number
CA1196736A
CA1196736A CA000447856A CA447856A CA1196736A CA 1196736 A CA1196736 A CA 1196736A CA 000447856 A CA000447856 A CA 000447856A CA 447856 A CA447856 A CA 447856A CA 1196736 A CA1196736 A CA 1196736A
Authority
CA
Canada
Prior art keywords
spring
coil
springs
portions
spring unit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA000447856A
Other languages
French (fr)
Inventor
Noboru Sasaki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
France Bed Co Ltd
Original Assignee
France Bed Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by France Bed Co Ltd filed Critical France Bed Co Ltd
Application granted granted Critical
Publication of CA1196736A publication Critical patent/CA1196736A/en
Expired legal-status Critical Current

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  • Springs (AREA)
  • Vehicle Body Suspensions (AREA)
  • Supplying Of Containers To The Packaging Station (AREA)

Abstract

Abstract of the Disclosure A plurality of main springs and a plurality of intermediate support springs are arranged on a rectantular base pale. Each main spring is made of a single steel wire and consists of two coil portions and a straight rod portion connecting these two coil portions. The rod portions of the main springs are arranted at right angles, thus forming a lattice. One end of each coil portion is fastened to a frame. The other end of each coil portion is fastened to the base plate. Each coil portion is shaped like cylinder, a cone, an inverted cone, a hourglass or a barrel.

Description

The present invention relates to a spring unit for use in a mattress or a box spring.
A conventional spring unit used in a mattress or a box spring comprises a plurality of main springs~ Each main spring is made of a single wire and has a straight rod portion and two spring protions. The upper ends of these spring portions are coupled to the ends of the rod portion. The main springs are disposed on a rectangular base plate. They are divided into a first group of long main springs and a second group of short main springs.
The long main springs are arranged parallel to the long sides of the base plate and the short main springs are arranged parallel to the short sides of the base plate.
Hence, the main springs of both groups form a lattice.
The lower ends of the spring portions are secured to the four edges of the base plate. The rod portions are reinforced by in-termediate support springs~ Like the main spring, each intermediate support spring has a straight rod portion and two spring portions. The upper ends of the spring portions are coupled to the ends of the rod portion, and the lower ends of -the spring portions are secured to the base plate.
In the conventional spring unit, the spring portions of the main springs and intermediate support springs are torstion bar springs. A torsion bar spring deforms very slightly when a compressive load is applied on it. However, it will be permanently deformed if a . ,~

6';'36 compressive load is applied on it many times. The known spring unit, which comprises torsion bar springs, may lose its elasticity in a relatively short time.
Therefore, the object of the present invention is to provide a spring unit which retains a high elasticity over a long period of time.
According to the invention, there is provided a spring unit a rectangular base plate; a plurality of main springs each having a first straight rod portion and two first coil portions which are connected at one end to the ends of the first straight rod portion, said main springs being disposed on said rectangular base plate with the first straight rod portions arranged at right angles to one another; first fastening means fastening the other end of each first coil protion to said rectangular base plate; a rectangular frame; first coupling means coupling said rectangular frame to said one end of each first coil portion; a plurality of intermediate support springs disposed on said rectangular base plate; second coupling means coupling one end of each intermediate support spring to the corresponding first straight rod portion; and second fastening means fastening the other end of each intermediate support spring to said rectangular base plate.
The accompanying drawings show an embodiment of the present invention, in which:

~i73~

Fig. 1 is a plan view schematically showing the structure of a spring unit;
Fig. 2 is a side view showing the structure of the spring unit;
Fig. 3 is a plan view of a main spring;
Fig. 4 is a side view of the main spring;
Fig. 5 is a plan view of an intermediate support sprlng;
Fig. 6 is an enlarged sectional view showing the state of connection of a pair of wire rods;
Fig. 7 is a side view showing a partial section of a coil spring and a base plate which are fixed to each other;
Figs. 8A to 8D are side view of the main spring of 1, another type respectively;
Fig. 9 is a plan view of the intermediate support spring of another type;
Fig. 10 is a perspective view of the intermediate support spring shown in Fig. 9;
Fig. 11 is a side view of a single coil spring; and Fig. 12 is a perspective view of a single torsion spring.
As shown in Figs. 1 and 2, a spring unit, an embodiment of the invention, has a base plate 1. The plate 1 comprises a rectangular base frame la and a plurality of parallel crosspieces lb fixed to the base frame la. The crosspieces lb are parallel to the short 11~6~3~

sides of the base frame la and spaced apart from one another at equal intervals. The spring unit further comprises a plurality of main springs 3, a plurarity of intermediate support springs 4, four corner springs 5 and a rectangular wire frame 6. The springs 3 and --springs 5 are disposed in a specific manner, as will be described later.
The rectanular wire frame 6 is made of a steel wire having a circular section profile. Its size is substantially the same as that of the base plate lr As shown in Figs. 3 and 4, each main spring 3 is made of a steel wire having a circular sectional profile and has a straight rod portion 8, and two coil portions 7 which are provided with two straight segments 9 respectively. The straight segments ~ are continuous to at one end to the ends of -the rod portion 8 respectively and the two coil portions 7 are continuous at one ends to the other ends of the straight segments 9 respectively. The axis Ll of one of the coil portions 7 and the axis L2 of the other coil portion 7 are parallel as illustrated in Fig. 4. The straight segments 9 are substantially at right angles to the rod portions 8, as shown in Fig. 3.
The main springs 3 are divided into, i.e., a first group of long springs 3 and a second group of short springs 3. On the base plate 1, the long main springs 3 are arranged parallel to the long sides of the frame la 3~

and the short springs 3 are arranged parallel to the short sides of the frame la. Hence, the rod portions 8 of the main springs 3 of both groups form a lattice.
The coil portions 7 of every main spring 3 are secured at the other ends to the frame la by staples 20, as illustrated in Fig. 7.
Each intermediate support srping 4 is made of a single steel wire having a circular sectional profile, like each main spring 3. As shown in Fig. 5, it has a straight rod portion 10a, first straight segments 11, a second straight segment 12, and coil portions 10. One of the first straight segments 11 is continuous at one end to one end of the second straight segment 12 whose other end is continuous to one end of the rod portion 10a. The other first straight segment 11 is continuous at one end to the other end oE the rod portion 10a. The upper end of the first coil portion 10 is con-tinuous to the other end of the first straight segment 11, and the other coil portion 10 is continuous to the other end of the straight segment 11. One of the straight segment and straight portion 11 and 12 are at right angles to each other, forming an L-shaped portion.
The straight rod portion 10a of each intermediate support spring 4 is much shorter than the straight rod portion 8 of each main spring 3. More specifically, the length of the rod portion 10a is substantially equal to the diagonal length of each box of the lattice formed by the rod portions 8 of the main springs 3.
As shown in Fig~ 1~ each corner spring 5 is made of a single steel wire having a circular sectional profile.
It has a coil portion 15, a straight portion 16, and a straight segment 17. The straight segment 17 is continuous to one end of the straigt portion 16 and inclined at a particular angle thereto. The upper end of the coil portion 15 is continuous to the other end of the straight portion 16.
As shown in Figs. 1 and 6, the rectangular wire frame 5 is fastented to the straight segments 9 of each main spring 3 by c'ips 13. Likewise, the upper ends of the coil portions of each intermediate support spring 4 are fastened by clips 13 to the xod portion 8 of one short main spring 3, respectively. The straight segments 11 thereof are fastened by clips 13 to the rod portions 8 of one long main spring 3 and the straight segment 12 thereof is also fastened by clip5 13 to the rod portion 8 of one short main spring 3, respectively.
Similarly, the upper end of the coil portion 15 of each corner spring 5 is fastend at two points by clips 19 to the corresponding corner portion of the frame 6. The straight segment 17 of each corner spring 5 is fastened by a clip 18 to the straight rod portion 8 of one main springs 3.
The clips 13, 14, 18 and 19 are metal strips having a predetermined width. Each clip is bent around two ~C~36 steel wires, thus bundling them together.
In the spring unit having the above-mentioned structure, both ends of the portion ~ of each main spriny 3 and those of the portion lOa of each intermediate support spring 4 are integrally formed with the coil spring portions 7 and 10, respectively. The deformation in each of the coil spring portions 7 and 10 due to a compressive load is greater than that in each torsion bar spring. However, even if the compressive load is repeatedly applied to the coil spring portions 7 and 10, there is no tendency for a permanent set to occur. Therefore, the spring unit will not lose its high elasticity at an early stage of use, unlike the conventional spring unit.
The wire frame 6 is fastened by the clip 14 to each straight segment 9 formed at one end of the coil spring portions 7 of each main spring 3 such that the straight segment 9 and straight portion of the wire frame 9 are in contact with each other. As a result, the contact ~ length between each main spring 3 and the frame 6 is greatly increased compared with the case where coil spring portions 7 do not have straight segments 9.
Accordingly, the coil spring portions 7 and the frame 6 will not become loose at an early stage of use and the frame 6 and the coil spring portions 7 do not strike each other, thereby no mechanical noi.se occurs since they are firmly fastened by the clips 14. The coil spring portions 7 of the main springs 3 are properly reinforced by the frame 6 over a long period of time.
Each straight segment 11 of each intermediate support spring 4 is fastened by a clip 13 to the corresponding portion 8 of a main spring 3 such that the straight portion 8 and segment 11 contact each other, thus ensuring the reinforcement of the portions 8 of the main springs 3.
Furthermore, the second straight segment 17 integrally formed with the portion 16 of each corner spring 5 is brought into tight contact with the portion 8 of the corresponding main spring 3 and is firmly fastened thereto by a clip 18. As a result, the second straight segment 17 and the portion 8 are firmly fastened to each other.
In the above-described embodiment, the spring unit is assembled by the main spring 3, intermediate spring 4 and corner spring 5 having the cylindrical coil portions 7, 10, 15.
However, the coil portions 7 of each main spring 3 may be shaped like an inverted cone as shown in Fig. 8B.
In other words, their diameter may decrease along their axes toward their lower ends. Their diameter is not so large that they touch each other. The coil protions 10 of each intermediate support spring 4 and the coil portions 15 of each corner spring 5 also may be identical with these coil portions 7 in shape and ~9~3~

g diameter. The coil portions 7, 10 and 15 are indeed more liable to elastically deform than torsion bar springs when a compressive load is applied on them, but they are less liable to permanent deformation than torsion bar springs. Hence, their elasticity is preserved over a long period of time, unlike that of torstion bar springs.
As mentioned above, in the modified embodiment, the coil portions 7, 10, 15 are shaped like an inverted cone. Hence, when a load acts on each coil portion 7, 10, 15 the turn of the greatest diameter is first elastically deformed, the turn of the second greatest diameter is then deformed, and so forth. When the spring unit is used as bed spring unit, it can comfortably support the user lying on the bed, regardless of his weightu In other words, the bed is neither too soft nor too hard to the user. Since the diameter of the coil portion 7, 10, 15 of each main spring 3 decreases toward the lower end, the turns do not contact one another when the coil portion 7 is compressed, thus generating no noise.
According to -the present invention, the shape of the coil portions of each main spring 3, intermediate spring 4 or each corner spring 5 is not limited to the cylindrical shape or the inverted cone shape. The coil portion may take any other non-cylinderical shape. For example, it may be shaped like a hourglass as shown in 3~

Fig. 8A. Alternatively, it may have such a conical shape as illustrated in Fig. 8C. Further, it may be shaped like a barrel as depicted in Fig. 8D.
In the embodiment described above, each main spring 3 is made o~ a single steel wire. Instead, it may be formed of two sections each of which is made of a steel wire. In this case, each section may have a straight rod element portion and a coil spring portion. The straight rod element portion o the sections may be coupled to that of the other section, thus forming a main spring 3 which has one straight rod portion consisting of the two coupled rod element portions.
In the above-described embodiment, moreover, each intermediate support spring 4 is provided with a coil spring portion 10. Alternatively, however, the coil spring portion 10 may be replaced with a torsion spring portion 20, as shown in Figs. 9 and 10. The torsion spring portion 20 is formed of a plurality of torsion rods 21 arranged parallel to one another; and a plurality of connecting rods 22, each of which is continuous to the corresponding two adjacent torsion rods 21. A straight rod portion lOa is continuous at both ends to the uppermost torsion rods 21 of the torsion spring portions 20. These torsion spring portions 20 can support the rod portions 8 of the main springs 3 with sufficient elasticity.
Furthermore, each intermediate support spring 4 may ;'73~

be replaced by a single coil spring 30, as shown in Fig. 11, or a single torsion spring 31, as shown in Fig. 12, which is not provided with the connecting rod portion lOa.

Claims (11)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. A spring unit comprising:
a rectangular base plate;
a plurality of main springs each having a first straight rod portion and two first coil portions which are connected at one end to the ends of the first straight rod portion, said main springs being disposed on said rectangular base plate with the first straight rod portions arranged at right angles to one another;
first fastening means fastening the other end of each first coil protion to said rectangular base plate;
a rectangular frame;
first coupling means coupling said rectangular frame to said one end of each first coil portion;
a plurality of intermediate support springs disposed on said rectangular base plate;
second coupling means coupling one end of each intermediate support spring to the corresponding first straight rod portion; and second fastening means fastening the other end of each intermediate support spring to said rectangular base plate.
2. A spring unit according to claim 1, wherein each of said intermediate support springts has a second straight rod portion which is shorter than any first straight rod portion and two second coil portions which are connected at one end to one end of the straight rod portion.
3. A spring unit according to claim 2, wherein said second spring portions are torsion springs.
4. A spring unit according to claim 1, wherein the second coil portions of each intermediate support spring are coil springs.
5. A spring unit according to claim 1, wherein said one end of each first coil portion has a straight segment which in tight contact with said rectangular frame.
6. A spring unit according to claim 1, wherein said one end of each second spring has a straight segment which is in tight contact with a corresponding first straight rod portion of the main spring.
7. A spring unit according to claim 1, wherein the two first coil portions of each main spring have axes parallel to each other, said one end of each first coil portion being coupled to said corresponding end of the first straight rod portion.
8. A spring unit according to claim 1, wherein each first spring portion is shaped like a cylinder, an inverted cone, a cone, a hourglass or a barrel.
9. A spring unit according to claim 1, wherein each second spring portion is shaped like a cylinder, an inverted cone, a cone, a hourglass or barrel.
10. A spring unit according to claim 1, wherein said intermediate support springs are single coil springs.
11. A spring unit according to claim 1, wherein said intermediate support springs are single torsion springs.
CA000447856A 1983-02-22 1984-02-20 Spring unit Expired CA1196736A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP28230/83 1983-02-22
JP58028230A JPS59155216A (en) 1983-02-22 1983-02-22 Spring apparatus

Publications (1)

Publication Number Publication Date
CA1196736A true CA1196736A (en) 1985-11-12

Family

ID=12242793

Family Applications (1)

Application Number Title Priority Date Filing Date
CA000447856A Expired CA1196736A (en) 1983-02-22 1984-02-20 Spring unit

Country Status (2)

Country Link
JP (1) JPS59155216A (en)
CA (1) CA1196736A (en)

Also Published As

Publication number Publication date
JPH0336526B2 (en) 1991-05-31
JPS59155216A (en) 1984-09-04

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