KR870002058B1 - Extensible strut - Google Patents

Abstract

The gas spring has a mechanism for locking the rod at a predetermined length position. Two axially contiguous recesses (13,14) in the rod define a ridge. A locking member (16) is rockingly movable between the recesses and has a pair of splayed legs (17,18). A resilient ring (15) locates the locking member in either of the recesses. A retaining element (21) secured to the cylinder cooperates with one leg of the locking member when the member is in the second recess, preventing movement of the rod in one direction. A releasing element (22) cooperates with the second leg of the locking member.

Description

Stretchable strat

1 is a longitudinal cross-sectional view of an extensible strat according to the present invention.

2-8 are partially enlarged views of FIG. 1 showing various modes of operation.

9 to 13 are views similar to FIGS. 2, 3, 5, 6, and 7, respectively, showing modified forms.

14 is a view similar to FIG. 1 showing a second embodiment of the present invention.

Figure 15 is a system diagram showing a cylinder deformation process.

16 is a system cross section showing a modified cylinder deformation process.

17 is a sectional view showing a third embodiment of the present invention.

18 is a cross-sectional view of the coupling member of FIG.

19 is a sectional view of a fourth embodiment of the present invention.

FIG. 20 is an enlarged front view of the fixing member of FIG. 19. FIG.

21 is a cross-sectional view of FIG.

FIG. 22 is a similar cross-sectional view of FIG. 20 showing a modified state.

23 is a sectional view of a fifth embodiment of the present invention.

24 is a sectional view of a sixth embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

1: cylinder 2: piston

4,10: mounting member 8: piston rod

15: elastic member 13, 14: recess

16 fixing member 17, 18 legs

22: release element 20: coupling member

24: annular projection 28: coil spring

29: annular stop 30: ridge or protrusion

45: elastic member

The present invention relates to a type of stretchable strut comprising a cylinder and a rod slidably guided by the cylinder and extending outwardly through one end thereof. An example of a typical strat is a gas spring.

It is usually necessary to provide a device for securing the stretchable strat to secure the strat in at least one predetermined length position. However, the fixing device proposed in the related art is complicated in structure and unreliable in function.

One object of the present invention is to provide a new strat having a fastening device which is simple in structure and reliable in function.

An extensible strat according to the invention is provided on a cylinder, a rod slidably guided by the cylinder and extending outwardly through one end of the cylinder, the outer circumferential surface of the rod defining a ridge or protrusion therebetween. Axially abutting first and second recesses with surfaces inclined in opposite directions, selectively swinging in either one of the first and second recesses, generally having a V-shaped cross section and axially spaced A fastening member comprising first and second leg portions which are raised and extend radially outwardly and snap the fastening member between the first recess and the second recess by biasing the fastening member toward the radial interior. A resilient means for moving, a retaining element provided in the cylinder and radially inwardly projecting, and provided in the cylinder and more than the retaining element A release element projecting radially inwardly in the longitudinal direction, wherein the retaining element and the release element are spaced apart in the axial direction by an amount larger than between the first and second legs of the fixing member, and the fixing member Is located between the retaining element and the release element in the second recess, the first leg is caught by the retaining element, thereby preventing the piston rod from moving, and the second leg is caught by the release element. It consists of such an array to be moved.

The structure of the present invention is simple and the fixing and releasing operation is very easy.

Further objects of the present invention will become apparent from the following description taken in connection with the accompanying drawings which illustrate certain suitable embodiments of the present invention.

1 shows a gas spring 35 constituting a suitable application of an extensible strat according to the invention, wherein the gas spring comprises a cylinder 1, one end of which is closed by a cap 3; A piston 2 slidably mounted to the cylinder 1, and connected to the piston 2 and extending outwardly through one end of the cylinder 1 and through the seal 11 and the rod guide 9. It consists of a piston rod (8). The mounting member 4 is fixed to the cap 3, and the mounting member 10 is fixed to the tip of the piston rod 8. A through hole or passage 5 is formed in the piston 2 to communicate two chambers 6, 7 partitioned by the piston 2 inside the cylinder 1.

The two chambers 6, 7 are filled with pressurized gas. This gas pressure normally urges the piston rod 8 in the extending direction due to the difference in the pressure receiving region on the piston 2 in the seals 6 and 7, so that no external force acts on the piston rod 8 at all. When not, the piston rod 8 takes the maximum extension position. The first recess 13 and the second recess 14 according to the invention are provided at the inner end of the piston rod 8, the recesses 13 and 14 having a ridge or protrusion 30 between them. It includes a surface that is inclined in a defined opposite direction and is generally symmetrical. The fastening member 16, which has a generally V- or U-shaped configuration and has radially outwardly extending first and second legs 17, 18, is provided in either one of the two recesses 13, 14; It is optionally installed. An annular elastic member 15 such as a ring coil spring or a rubber ring is fitted to the fixing member 16 such that the fixing member 16 is snapped to either of the recesses 13 and 14. In the embodiment of FIG. 1, the recesses 13 and 14 and the fastening member 16 are provided at a predetermined angular position with respect to the circumference of the rod, but it is seen that they respectively extend in the circumferential direction by the required area of about 90 degrees. Could be. The recesses 19 are formed at the longitudinal positions substantially coincident with the positions of the ridges 30 and at the respective positions opposite to the recesses 13 and 14 for fixing the elastic members 15.

An annular engagement member 20 having an outer diameter corresponding to the inner diameter of the cylinder 1 is fitted to the cylinder 1 and fixed thereto by an annular projection 24 formed on the inner circumferential surface of the cylinder 1. According to the invention, the retaining element 21 and the disassembling element 22 are provided on the inner circumferential surface of the coupling member 20.

The retaining element 21 and the release element 22 are spaced apart at an axial distance greater than the legs 17, 18 of the fixing member 16, and the release element 22 is more than the retaining element 21. It extends radially inwards by a large distance. Moreover, the retaining element 21 generally has a wall portion extending radially and a wall portion gradually inclined axially and radially outward.

The cylinder 1 is also provided with spring retainers 26, 27 and coil springs 28 axially out of the engagement member 20. An annular stop 29 is mounted on the piston rod 8 to cooperate with the spring retainer 26 to elastically limit the outward movement of the piston rod 8 (rightward direction as seen in FIG. 1). Normally, the piston rod 8 takes the most extended position, in which the gas pressure acting on the piston 2 is in a state in which the spring retainer 26 and the annular stop 29 engage with the coil spring ( 28, the fixing member 16 is positioned between the retaining element 21 and the release element 22 of the coupling member 20 in the second recess 14.

In use, the gas spring 35 can be used in an automotive manner, for example, with the mounting member 4 on the cap 3 connected to the vehicle body and the mounting member 10 on the rod 8 connected to something such as a hatch backdoor. Is mounted on. When opening the door, the gas spring 35 extends to assist the opening movement of the door.

When the door is fully open, the gas spring takes on a normally fully extended position as shown in FIGS. 1 and 8, in which the fastening member 16 is engaged in the second recess 14. It is located between two elements 21 and 22 of (20). The weight of the door tends to retract the gas spring, which then prevents further contraction of the piston rod 8 as the first leg 17 engages the retaining element 21 as shown in FIG. The gas spring is fixed efficiently and securely.

2 shows a state in which the fixing member 16 is displaced radially outwardly against the force of the elastic ring 15 as a relatively large compressive force acts on the gas spring.

When releasing the locked state, the piston rod 8 is first moved in the direction of extension or in the direction of arrow A by displacing the spring retainer 26 against the force of the coil spring 28. The releasing element 22 is shown in FIG. 3 until the fixing member 16 snaps into motion as it swings from the second recess 14 to the first recess 13 as shown in FIG. As shown, the second leg 18 of the fixing member 16 is engaged. After that, the piston rod 8 is moved in the direction of the arrow β or in the contracting direction.

The second leg 18 is caught by the retaining element 21, and in response to the movement of the piston rod 8, the fastening member 16 has a first recess 13 as shown in FIGS. From the second recess 14 to move in a snap. As can be understood from FIG. 6, it can be seen that a radial gap exists between the second leg 18 and the retaining element 21 when the fixing member 16 is positioned in the second recess 14. . The piston rod 8 may be moved in the direction of the arrow β by the full stroke.

When the rod moves in the direction of arrow A, the inclined wall portion of the retaining element 21 engages with the first leg 17 of the fixing member 16 to counterclock the fixing member 16 as shown in FIG. While moving in the opposite direction, the fixing member 16 is not displaced from the second recess 14 to the first recess 13, and consequently the fixing member 16 is shown in FIG. As shown, it is positioned between the retention element 21 and the release element 22. Thus, the gas spring is held stationary.

The fixing device according to the invention is particularly suitable for use in gas springs when the pressure of the gas sealed in the gas spring is reduced such that the ambient temperature is reduced so that the gas spring cannot be maintained at its maximum extension by the sealed gas. It is advantageous.

9 to 10 show a modified form, wherein the first and second recesses are annular, and the plurality of fastening members 16 ′ spaced apart in a circumferential manner are provided with recesses 13, respectively. 14) It is selectively snap mounted on any one of them. The annular elastic member 15 'acts on the fixing member 16'. The operation and function of this embodiment are similar to those of the first embodiment.

14 and 15 show a second embodiment, which is generally similar to the first embodiment of FIG. The retention element 21 'is formed separately from the release element 22'. The retaining element 21 'is formed by radially inwardly deforming the cylinder 1 by using a curling roller 31 (FIG. 15). Preferably the retaining element 21 'defines a radially extending wall portion 21'a and generally an arcuate wall portion 21'b. FIG. 15 shows that the engaging member 20 'is used as a jig in deforming the cylinder to form the retaining element 21', but any suitable jig may be used. The engaging member 20 'is fixed to the cylinder at a predetermined position with respect to the retaining element 21' by curling or caulking the cylinder.

FIG. 16 shows a modified form, in which the retaining element 21 "does not extend along the entire circumference of the inner surface of the cylinder but extends along a facing range about 60 degrees in diameter. ) Is not rotated by about 30 degrees.

17 and 18 show a third embodiment of the present invention, wherein the coupling member 20 "'is provided with a metal tube having an inwardly extending flange at one end to define the retaining element 21", and a metal tube. It is formed into a cylindrical block that is fitted to define the release element 22 ". In addition, this embodiment is similar to the three fixing members 16 'spaced circumferentially and similarly to FIGS. It has annular recesses 13 and 14 defining the first and second recesses according to this, and an elastic ring 15 '. The operation and function of this embodiment are similar to the first embodiment.

19 to 21 show yet another embodiment, in which the resilient ring in the former embodiment is omitted and a generally C-shaped fixing member 36 formed of something like spring steel is provided. The fixing member 36 has a first leg 36b and a second leg 36c for cooperating with the retaining element 21 and the release element 22 of the coupling member 20, respectively. The cutout 36d of the fixing member 36 serves to elastically shrink its diameter. The radially inner surface portion 36a of the fastening member 36 is selectively engaged with the annular recesses 13, 14. The fixing member 36 shown in FIG. 21 is slightly expanded by applying an axial force in the right direction.

FIG. 22 shows the fixing member modified from the fixing member of FIG. The fixing member 37 of FIG. 22 is a rubber ring having annular core plates 38 and 39 for defining the first and second legs according to the present invention.

FIG. 23 shows a fifth embodiment of the present invention, wherein the piston rod 8 can be fixed in the retracted position by the fastening mechanism according to the present invention. Annular recesses 13 'and 14' for selectively snapping a plurality of fastening members 46 spaced circumferentially on the inner end of the piste rod 8, and fastening members. An elastic ring 45 is provided for urging 46 inwards radially inward. The structure of the retaining element 51 and the releasing element 52 is generally similar to the embodiment of FIG. Furthermore, the spring retainer 53 and the coil spring 54 cooperate with the inner end of the piston rod 8 to define the most retracted position of the piston rod 8 in the steady state. When the piston rod 8 overcomes the force of the coil spring 54 and further contracts, the fixing member 46 has a first recess 13 as described above with reference to FIGS. 3 and 10. Move to '), and the lock is released. That is, the function of the coil spring 54 is similar to that of the coil spring 28 in the first embodiment. However, it will be appreciated that coil spring 54 may be omitted. In such a case, it is desirable to set the axial distance between the retaining element and the release element sufficiently larger than the axial length of the fixing member, and to give an appropriate indication regarding the contracted length of the rod to distinguish between the fixed state and the released state.

24 shows another embodiment of the present invention, in which two sets of fixing mechanisms according to the present invention are provided to fix the piston rod 8 in the most extended and the most retracted state. The holding mechanism for the most retracted state is similar to the embodiment of FIG. 23 and the holding mechanism for the most extended state is generally symmetrical with respect to the former. Therefore, detailed description thereof will be omitted.

It will be appreciated that the present invention is not limited to gas springs but may be applied to other types of stretchable strat.

According to the invention, the rod can be reliably retained with respect to a cylinder having a very simple structure, and the fixed state can be easily released.

Claims (10)

In an extensible strat, a cylinder (1), a rod (8) guided by the cylinder and extending so as to slide outwardly through one end of the cylinder, provided on the outer circumferential surface of the rod and provided with a ridge or protrusion ( Axially abutting first and second recesses 13, 14: 13 ′, 14 ′ having surfaces inclined in opposite directions defining 30 therebetween, and any of the first and second recesses. Fixation comprising first and second legs 17, 18: 36b, 36c: 37b, 37c, selectively swinging in one and extending radially outward with a generally V-shaped cross section Snap members 16, 16 ', 36, 37, 46, 46' and the fixing member by biasing the fixing member toward the radially inner side to snap the fixing member between the first and second recesses. Elastic means 15, 15 ', 36, 37, and a retention element provided in the cylinder and protruding radially inward (21, 21 ', 21 ", 21"', 51, 51 ') and release elements (22, 22', 22 "', 52, 52 provided in the cylinder and protruding radially longer than the holding element). '), Wherein the retaining element and the release element are axially spaced apart at an interval longer than the gap between the first and second legs of the retaining member, and the retaining member is separated from the second element between the retaining element and the release element. When placed in the set, the first leg 17 is caught by the retaining element, thereby preventing the piston rod from moving in one direction, and the second leg is caught by the release element in accordance with the movement of the rod moving in the other direction. An extensible strat, characterized in that arrangement consists of moving in one recess. 2. The stretchable strat according to claim 1, wherein the cylinder comprises a gas pressurized therein and the rod is a piston rod (8) connected to a piston (2) acting in the cylinder. 2. The annular member (20) according to claim 1, wherein the first and second recesses are provided at the inner end of the rod, and the retaining and releasing element is fixed to the inner circumferential surface of the cylinder at a position near one end of the cylinder. 20 "') stretchable strat. 3. The fixing member and retaining element of claim 2 further comprising resilient means (26,28,29) for cooperating to hold the piston rod in an extended position and for the strat to define the position of the normally extended piston rod. Elongated strass, characterized in that. The stretchable strat of claim 1 wherein said first and second recesses are annular. 6. The stretchable strat according to claim 5, wherein the plurality of circumferentially spaced fixing members are held on either one of the first and second recesses by an elastic ring surrounding the fixing member. 6. An elastic ring (37) incorporating the annular core plates (38, 39) to form the first and second legs, according to claim 5, constitutes a fastening member and, due to its elasticity, the first and second ribs. Elongated strat, characterized in that located in any one of the set. 6. A generally C-shaped resilient member (36,37) constitutes the fixing member and is located in either of the first and second recesses due to its elasticity. Stretchable strat. 2. The stretchable strat according to claim 1, wherein said retaining and releasing element is placed in a position close to said other end of the cylinder to fix the rod in a retracted state. 5. The resilient means for defining the position of the normally extended piston rod further comprises a stop (29) secured to the piston rod and a spring (28) for receiving gas pressure acting on the piston and the piston rod being at said maximum. And a spring retainer (26) that engages said stop when extending to an extended position.

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