JPH0625724Y2 - Tension spring - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention mainly relates to a tension spring used in a gas valve device and other relatively small devices.

(Prior Art) Conventionally, a coil spring is generally used as a tension spring.

(Problems to be solved by the invention) However, the coil spring has a cylindrical shape because it is formed by winding a wire in a spiral shape, and has a relatively long length and a wide width, so that it is limited to a gas valve device of a combustion appliance. There is a problem that it is difficult to use as a tension spring for equipment installed in a closed space.

The present invention aims to obtain a tension spring that does not have such a problem.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a tension spring according to claim 1, wherein a wire rod having elasticity is curved in an annular shape, and both ends thereof are partially overlapped with each other. And two points in the diametrical direction of the ring body are the respective points of action with which the action members for exerting a tensile force outward are engaged, and the ring body receives the tensile force at both ends thereof. The engaging portions that engage with each other when the diameter increases are projected inward of the ring body.

3. The tension spring according to claim 2, wherein a wire having springiness is curved in an annular shape to form an annulus provided with parts that partially overlap at both ends thereof, and a part of the annulus that partially overlaps and a part that does not overlap. The two points in the diametrical direction passing through are the points of action at which the action members that exert a tensile force outward are engaged, and the diameter of the wire rod is expanded at both ends of the wire rod by the tensile force. At this time, the engaging portions that engage with each other via the acting member are projected toward the inside of the ring body.

(Operation) In the tension spring according to claim 1 having the above structure, when a tensile force is applied to the ring body by the acting member outward in the diameter direction of the ring body, the ring body forms the ring body. The acting member can be moved by causing a deviation in the direction in which the overlapping portions of the wire rods decrease. However, when the locking portions at both ends of the wire rod are brought into engagement with each other, there is no overlapping portion of the wire rods constituting the ring body, and thereafter, the ring body is elastically deformed into an elliptical shape. Since the acting member moves due to this, it does not move unless an extremely large external force is applied to the acting member.

Therefore, this position can be set as the movement limit position of the action member.

When the external force acting on the acting member is removed, the acting member returns to the original position by the restoring force of the ring body to the original shape.

In the tension spring according to claim 2 having the above structure,
When a tensile force is applied to the annular body by the acting member in the diametrical direction of the annular body, the annular body is displaced in the direction in which the overlapping portions of the wire rods forming the annular body are reduced, and the movement of the acting member is prevented. It will be possible.

However, when the locking portions at both ends of the wire rod are brought into a state of being engaged with each other through the action member, there is no overlapping portion of the wire rods forming the ring body, and thereafter, the ring body is elastically deformed into an elliptical shape. Since the acting member moves along with the deformation, it does not move unless an extremely large external force is applied to the acting member.

Therefore, this position can be set as the movement limit position of the acting member. When the external force acting on the acting member is removed, the acting member returns to the original position by the restoring force of the ring body to the original shape.

Moreover, since the part of the ring body where the ring member partially overlaps is set as the point of action for engagement of one of the action members, even if the ring member rotates and the action member comes to the end of the wire rod, the action member does not become the locking portion. Since it is locked, the acting member does not come off from the ring body.

(Embodiment) An embodiment of the present invention will be described with reference to the attached drawings.

In the drawing, reference numeral 1 indicates that a tensile force acts on the diametrically outward direction of a ring body 3 in which a steel wire or other wire material having a spring property is curved in an annular shape and portions 2 and 2 partially overlapped at both ends thereof are formed. The tension spring 1 is formed by bending both ends of the annularly curved wire inwardly of the ring body to form the locking portion 4.

As shown in FIG. 2, the tension spring 1 has two action members X, which exert a tensile force outwardly at two diametrical points passing through the portions 2 and 2 where the wire rods overlap and the portions which do not overlap.
Each of the action points is engaged with Y. More specifically, the tension spring 1 is provided on the ring body 3 in the middle of the locking portions 4 and 4 at both ends thereof, as shown in FIG. 2a. The action member X moving outward in the diametrical direction of the ring body 3 is engaged with the one side action point, and the fixed action member X is engaged with the other side action point in the diametrical direction passing through the action point. Then, the tensile force is applied to the outside in the diameter direction of the ring body 3.

Thus, when the action member X is moved in the direction of the arrow shown in FIG.
2 allows movement of the working member X while decreasing. Therefore, the tension spring 1 has a relatively soft spring characteristic.

In addition, the ring member 3 is pulled by the acting member X and is rotated by repeated operations such as unraveling, so that the acting member X
Even when the wire rod comes to the end of the wire rod, the acting member X is locked by the locking portion 4 and therefore does not come off from the ring body 3.

Then, when the locking portions 4 at both ends of the wire are engaged with each other via the action member X, or when the both locking portions 4 and 4 are engaged with each other, the annular body 3 is moved in the pulling direction next. With the elastic deformation that deforms into an ellipse, the action member X can be further moved. Therefore, after that, it shows a very hard spring characteristic. Therefore, depending on the rigidity of the wire rod, the state position in which both the locking portions 4 and 4 are engaged via the action member X or the state position in which both the locking portions 4 and 4 are engaged is set to the action member X. It is also possible to set it at the movement limit position.

3 and 4 show a gas valve device c having a gas outlet a connected to the first burner and a gas outlet b connected to the second burner.
In a heater provided with a switch for switching the capacity of the heater by a switching valve d interposed upstream of a gas outlet b connected to the second burner, a lock for locking a switching lever e for switching the switching valve d to the switching position. An example of use in which the tension spring 1 is applied to the pin f will be shown. Explaining this, the switching lever e has an L-shape, and one side thereof is the operation piece e-1.
The other side is a lock piece e-2 that engages with the lock pin f. One end of the lock pin f is swingably supported by the machine frame g, and the other free end of the lock pin f is engaged with the tension spring 1 so that the lock pin f faces the movement locus of the lock piece e-2. . When the switching lever e is switched from the original position A shown by the solid line to the switching position B shown by the chain line, the lock pin f is pushed by the end surface of the lock piece e-2 and resists the tension spring 1 to lock the lock. After retreating from the movement path of the piece e-2, the lock piece e-2
When it reaches the switching position, the tension spring 1 faces the movement locus of the lock piece e-2 and locks it at the switching position as shown by the chain line. Since the tension spring 1 is extremely flat, a locking piece h formed by cutting and raising a part of the machine frame g.
By locking this to the outside of the machine frame g, it can be installed in a state of being in close contact with the machine frame g. Therefore, when the tension spring 1 is used, it is not necessary to consider the installation space of the tension spring 1 when assembling the gas valve device c in the heater, unlike the coil spring conventionally used, and the overall size of the device is reduced. Can contribute to.

(Effects of the Invention) As described above, the tension spring according to claim 1 having the above-described configuration is formed to be extremely flat, so that a device using the tension spring can be downsized. Moreover, when a tensile force is applied to the ring body in the diametrical direction, the ring body is displaced in the direction in which the overlapping portions of the wire rods forming the ring body are reduced, and the action member can move. When the external force acting on the working member is removed, the acting member can be returned to its original position by the force of the annular body returning to its original shape, and a relatively soft tension spring force acting on the actuating member can be obtained. However, when the locking parts at both ends of the wire are in the engaged state, there is no overlapping part of the wire forming the ring body, and the action member can be moved exclusively with elastic deformation of the ring body. Therefore, unless an extremely large external force is applied to the action member, the action member does not move, so that the position can be set as the movement limit position of the action member.

In the tension spring according to claim 2 having the above structure,
Since it is formed to be extremely flat, a device using the same can be downsized, and when a tensile force is applied to the ring body in the diametrical outward direction, the ring body is made of a wire material constituting the ring body. When the action member is allowed to move while shifting in the direction in which the overlapping portions decrease, and when the external force acting on the action member is removed, the action member may be returned to the original position by the force returning to the original shape of the ring body. As a result, a tension spring having a relatively soft force acting on the acting member can be obtained. However, when the locking portions at both ends of the wire rod are brought into a state of being engaged with each other through the action member, there is no overlapping portion of the wire rods forming the ring body, and the ring body is exclusively elastically deformed. Since it becomes possible to move the action member without applying a very large external force to the action member, the position can be set as the movement limit position of the action member, and a part of the ring body can be obtained. Since the overlapping portion is used as an action point where one of the action members engages, even if the action member comes to the end portion of the wire rod due to the ring body being pulled by the action member and rotating, one of the action members does not move. It has an effect that it can be used in a stable state without being disengaged from the annulus because it is between both locking parts at the end of the.

[Brief description of drawings]

FIG. 1 is a perspective view of an example of the present invention, FIG. 2 is an explanatory view for explaining the operation thereof, and FIGS.
FIG. 4 is a side cross-sectional view showing an example, and FIG. DESCRIPTION OF SYMBOLS 1 ... Tension spring, 2 ... Overlapping part 3 ... Ring body, 4 ... Locking part

Claims (2)

[Scope of utility model registration request] Claim: What is claimed is: 1. A wire body having a spring property is curved in an annular shape to form a ring body having overlapping portions at both ends thereof, and two diametrical points of the ring body are subjected to a tensile force outward. At the respective points of action of the action member, locking portions which engage with each other when the ring body receives a tensile force and its diameter expands are provided at both ends of the wire rod inside the ring body. A tension spring characterized by being projected toward. 2. A wire body having a spring property is annularly curved to form a ring body having overlapping portions at both ends thereof, and a diametrical direction passing through a partially overlapping portion and a non-overlapping portion of the ring body. The two points are the points of action at which the action members that exert a tensile force outward are engaged, and at both ends of the wire rod,
A tension spring, characterized in that when the ring body receives a tensile force and its diameter increases, a locking portion that engages with each other via the acting member is projected inward of the ring body.