JPS6239773B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mechanical locking device, and more particularly to a mechanical locking device that grips a rod with a coil spring, tightens the rod to prevent translational movement relative to a housing, and selectively tightens the rod to prevent translational movement relative to the housing. The present invention relates to a locking device configured to allow such translational movement.

Friction brake locking devices in which the rod fits into a cylindrical housing are well known. Normally, the rod is locked to the housing to prevent axial translational movement relative to the housing, but the locking device is configured to allow axial translational movement of the rod. It can be selectively activated to the unlocked state. A coil spring is attached to the housing so as to be coaxial with the rod. This spring grips the curved surface of the rod and locks it against movement relative to the housing. The operator can partially loosen the coil spring using the operating lever to increase the inner diameter of the spring and release the grip on the rod. This allows the rod to move freely in the axial direction inside the coil spring.

The use of coil springs to grip internally threaded rods is well known. Many locking devices using this basic mechanism are known. Part 1
An example is disclosed in US Pat. No. 3,249,180. As shown in FIG. 10 of the same patent, in this device, one end of a coil spring 108 is attached to a fixed ring 109, and the other end is attached to a rotatable ring 110.
It is adapted to be engaged by. The ring 110 engages a longitudinal groove in the rod so that as the rod is turned, the ring also rotates to tighten the spring and tighten its grip on the rod. The rotating ring and the stationary ring are provided with abutment members for tilting the spring against the rod. When the spring is tightened, the grip of the spring on the rod increases when an axial load is applied to the rod, thereby providing a true locking action. This mechanical part of the device is also disclosed in US Pat. No. 2,750,994. As clearly shown in FIG. 5 of this patent, in this device only the fixed sleeve 25 is provided with a beveled base 40, and the device is actuated by turning the opposite end 31 of the spring. Ru. Therefore, with this device, a large number of turns of the spring must be unwound and loosened in order to extend the diameter of the spring to the fixed end of the spring. Therefore, the stroke of the operating lever must be unnecessarily long.

Another type of locking device is shown in U.S. Pat. No. 3,874,480. In the device of this patent, as shown in FIG.
The springs are coaxially arranged extending in opposite directions from the central operating lever, and the outer ends of the springs are attached to fixed locking bushes located at opposite ends of the housing sleeve. One of these locking bushes locks the locking device in the tensioned state, and the other bushing locks the locking device in the compressed state at the end of the last two or three of the ends of each spring remote from the operating lever. The locking effect is exerted by the interaction between the winding and the corresponding bushing. Things to keep in mind are:
In the device of this patent, at a particular moment in time, 2
Although only one of the springs acts against tension or compression, both springs must nevertheless be unwound simultaneously using the operating lever to unlock the device. It is. The control lever must be moved over a stroke sufficient to unwind the entire length of each spring, thereby ensuring that the last two to three turns of each spring are unwound. do. For this purpose, the operating lever must be moved over a long stroke against the forces of the two springs resisting unwinding. Therefore, unlike the present invention, the stroke of the operating lever and the force required for its operation are large. Although this structure works well, in installation locations where space is a constraint, a friction brake device is required that has a short stroke of the operating lever and operates with relatively little force.

Although the structure of US Pat. No. 3,874,480 is satisfactory in terms of performance, it is complex.

The end bushings for attaching the outer ends of the two springs to the sleeve of the housing must be rotated during the assembly process to a position where the inner ends of both springs abut the operating lever in equilibrium. To rotate the bush in this manner, the grip of at least one spring must be released by unwinding that spring. In fact, assembly of this device requires highly skilled winding techniques to ensure that both springs are properly compressed and twisted relative to the operating lever.
In contrast, the present invention does not require such complicated assembly work.

Also, U.S. Patent Nos. 2434480, 3330595, and
No. 2429383 and No. 3064766 also disclose locking devices, but these locking devices also fundamentally differ from the present invention in that they do not include a beveled bush for receiving a spring. .

It may be desirable to provide a mechanical locking device that requires less force to release the locking mechanism and also requires less movement (stroke) of the operating lever to release the locking mechanism. . One example of such an application is car seats. It is desirable that the displacement of the back of a motor vehicle seat between an upright position and a reclined position occur smoothly and without jerky movements. Furthermore, if the locking mechanism is of the direct control type, i.e. the user operates a release lever rather than a remote controlled linkage;
The force required for the release operation and the stroke of the operating lever should be reduced.

Although this objective can be achieved, one practical consideration is to achieve the objective with a relatively inexpensive device, yet with a long useful life. Additionally, it would be desirable to have a device that requires virtually no maintenance, is capable of operating over a wide range of temperature conditions, and is not affected by water, dust, etc.

According to the present invention, a single spring is used instead of two springs as in the above-mentioned US Pat. No. 3,874,480, thereby reducing the required actuation force by half. A single spring has a stationary locking bushing at one end and a rotatable locking bushing at the other end of the spring. The springs interact with these locking bushes to prevent axial movement of the rod in either direction. The rotatable locking bush is adapted to be turned by an operating lever. It works to lock the rod in one direction. Since the last few turns of the spring are adjacent to the rotatable locking bush, it is not necessary to unwind the entire spring to release their grip on the rod. Therefore, the release operation is smooth. This is because the remaining part of the spring acts as a frictional resistor,
This is because it prevents the spring release action and thus avoids the sudden movements normally associated with a spring release action. Two or three turns of the spring can therefore be released by a short stroke of the operating lever. Thus, the present invention provides a mechanical locking device that requires less force for the release operation, has a short stroke, and yet provides a smooth release operation. These features make it practically possible to use a direct-control pushbutton controller as a control means for operating the operating lever. The use of a push button type controller is highly desirable from the viewpoint of aesthetic appearance or external appearance.

Another feature of the invention is that the operating lever is located outside the area of the spring. especially,
The locking zone between the two or three turns of the spring and the rod is covered with an opening through which the operating lever can be inserted, in order to prevent dust, soap or cleaning liquid from entering. The inside of the device is filled with high-temperature resistant grease for airplanes or automobiles that does not flow at high temperatures.

A further feature of the invention is that the assembly of the device is simplified with reference to the accompanying drawings, which show a mechanical locking device 10 according to a preferred embodiment of the invention. The locking device 10 includes, for example, as shown, a cylindrical housing 14 and a cylindrical rod 12 disposed within the housing and selectively slidable relative to the housing along an axis 13. We are prepared.

Under normal conditions, the rod 12 is connected to the housing 14.
It is locked in a fixed position in the axial direction.

This relationship will not be released unless the operator moves the operating lever 16 to unlock the device and allow the rod 12 to be axially displaced to a new position relative to the housing 14.

The illustrated mechanical friction locking device 10 can be used to position the backs of reclining seats commonly used in passenger aircraft, trains, automobiles, and the like. The locking device is provided with an attachment member 18 and a trunnion 20 for attaching it to a suitable location on the seat. Housing 1 of mounting member 18
forming a groove 21 in a portion received within one end of 4;
The housing 14 is placed into this groove as shown, and the process is simplified. The above U.S. patent no.
Unlike the locking device of No. 3,874,480, the parts of the device of the present invention are assembled along the rod and inserted into the housing sleeve, and then the parts are removed by assembling the locking device into the sleeve. is fixed to the sleeve.

Because the spring of the present invention is shorter than the spring used in the device of US Pat. No. 3,874,480, the overall length of the locking device is also shorter. The length-to-diameter ratio of the device is correspondingly small and therefore the device has a high bending resistance or axial load-bearing capacity.

Since the mechanical locking device of the present invention has a short overall length and is easy to assemble, it can be manufactured at approximately half the cost of conventional locking devices. Also,
The locking device of the present invention is considerably lighter in weight than conventional devices and is suitable for use in airplanes and automobiles.

The above and other objects, features and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings.

It is fixed to the mounting member 18. The housing 14 is fixed to, for example, a stationary portion (seat portion) of a seat via this attachment member. A stop 22 is provided at one end of the rod 12 as a means for limiting the amount of movement of the rod 12 relative to the fixed housing 14. The other end of the rod may be provided with an eyelet 23 or any other means for attaching it to the moving part (back) of the seat.

A rotatable first bushing 24 is disposed within the housing 14 adjacent to the mounting member 18, and the rod 1
Fit it onto the outer periphery of 2. A second fixing bush 26 is mounted within the other end of the housing 14, and the rod 1
Fit the other end of 2. Button 26 also has groove 2.
A groove 27 similar to 1 is formed so that the housing 14 can be upset and secured to the bushing 26 using this groove. Rotatable bush 2
4 can be formed with an axial groove 28 for receiving the end of the operating lever 16.

A helical coil spring 30 is disposed between bushes 24 and 26 and surrounds a portion of rod 12. Each end of the spring 30 is provided with a radially extending protrusion or insert portion 31, 32, respectively. The bushing 24 is formed with an axial slot 34 for receiving the insertion portion 32 of the spring 30;
The fixed bushing 26 is formed with an axial slot 36 for receiving the plug-in part 31. Thus, one end of the spring 30 is fixed against rotation, and the other end of the spring can be turned by rotating the bush 24.

In the normal rest seated position of the lever 16, the spring 30 frictionally engages the outer circumference of the rod 12 to lock it in a fixed axial position relative to the housing 14. Movement of the operating lever 16 causes the rotatable bush 24 to unwind the spring 30 and release its grip on the rod 12. Depending on the direction of winding of the helical coil spring, the direction of release movement of the lever 16 will be either up or down as viewed in the figures, turning the bush 24 in either direction to release the rod 12. When released, the lever 16 automatically returns to the locking position and the spring 30 frictionally engages the circumferential surface of the rod 12.

The rotary bushing 24 is formed with an annular inner beveled surface or inclined cam surface 38, and the stationary bushing 26 is formed with an annular inner beveled surface or inclined cam surface 39.
These beveled surfaces 38 and 39 impinge on a portion of the last turn of the respective end of the spring 30 and tilt the last few turns with respect to the rod 12.
, thereby locking the rod in tension and compression, respectively, with true locking action. The term ``knotk'' here means that the windings of the coil spring are inclined with respect to the axis of the rod so that they are strongly pressed against the circumferential surface of the rod. Also, "locking engagement" refers to an interaction in which increasing the applied force results in a stronger locking of the associated parts.

By turning the rotary bush 24, the spring 30
The spring is unwound to ensure that the slack in the spring is transferred to the end of the spring held by the fixed bushing 26, rather than being accumulated in the spring windings adjacent to the bushing 24. A sleeve 40 surrounding 30 can be provided. Although in the illustrated embodiment a separate sleeve 40 is provided, in an alternative embodiment the length of each bushing 24, 26 may be extended inwardly so that the inner ends of each bushing 24, 26 meet. In this case, the extended bush plays the role of the sleeve 40, so there is no need to provide a separate sleeve. One advantage of this variation is increased bending resistance along the axis of the housing 14.

In the illustrated embodiment, a collar 42 having two spaced apart fingers 43, 44 is fitted onto the housing 14. The fingers 43, 44 can be fixed to the lever 16 by welding or the like, so that when the lever 16 is operated, the collar 42 is also rotated relative to the housing 14. The lever 16 passes through a window or opening 45 in the housing 14 and fits into a groove or slot 28 in the bushing 24. The collar 42 is the lever 16
As it rotates with the window 45, it acts as a cover over the window 45 and prevents dust and other foreign matter from entering the housing through the window 45.

As mentioned earlier, the mounting member 18 and the bushing 2
6 is filled with a lubricant such as grease that does not flow even at high temperatures and is stable against high temperatures. Collar 42 therefore also serves to help retain grease within the housing.

The window 45 is located in alignment with the slot 28 of the bush 24 rather than facing the area of the spring 30. Therefore, in reality, the foreign object is in the window 4.
5 and into the housing through the bushing 24.
The locking area of the spring 30 (the area for gripping the rod 12) passes between the outer peripheral surface of the spring 30 and the inner wall surface of the housing.
It rarely penetrates into the This is a practical advantage compared to conventional structures, especially in the case of locking devices used in motor vehicles.

In operation, due to the small circumferential dimensions of the window 45 in the housing 14, only a small amount of movement (stroke) of the lever 16 is required to release the rod 12. Furthermore, because the present invention uses only one spring with one end fixed and the other end movable, less force is required to release the rod. This reduction in force requirements is also due to the fact that the only effective locking portion of the spring 30 is the last few turns adjacent to the rotary bushing 24. To achieve this type of lock, the bushes 24 and 26 are provided with beveled surfaces 38 and 39, respectively, against which the final turns of the coil spring at each end abut. The provision of these beveled surfaces results in an immediate, gradual release of the spring by slight rotation of the bush 24. That is, it is not necessary to transmit the release action over the entire length of the spring 30. This mode of operation is such that when the last few turns of the spring are unwound, the remaining portion of the spring acts as a frictional resistor to gradually release the spring, allowing the rod 12 to be released smoothly. It is a great practical advantage that a sudden spring release at the moment when the lever 16 is operated, and thus a sudden movement, can be avoided.

The structure of the device according to the invention also has the advantage of simplifying assembly operations. That is, in this assembly, the fixed bush 26, spring 30, sleeve 40, and rotary bush 24 are sequentially slid onto the rod 12, and the bushes 24 and 26 are rotated to remove the protruding portion of the spring 30, that is, the insertion part. Part 31, 32
are inserted into the slots 36 and 34, respectively. Next, the housing 14 is fitted over the above-mentioned parts attached to the rod 12, and is upset and fixed to the mounting member 18 and the fixing bush 26. Next, the operation lever 16, the stop body 22 and the collar 4
Attach 2 each. During this assembly process, grease is injected into the assembly prior to installing the collar 42.

As explained above, the friction locking device of the present invention can be unlocked by operating the operating lever with a shorter stroke and smaller required actuation force than conventional ones. According to the invention, a rotatable locking bush is provided which is rotated by an operating lever, and two to three springs adjacent to this bushing serve to lock the rod in one direction. Since it is only a winding, it is not necessary to unwind the entire spring to release the spring's grip on the rod. Since the stroke of the operating lever is thus shortened and the force required to actuate the lever is reduced, the use of a directly controlled pushbutton as a means for operating the lever becomes practical. The use of pushbuttons is highly desirable from a style standpoint. The device of the present invention reduces manufacturing costs by about half that of conventional devices due to the combination of simplified assembly operations and shortened length of the device. The low length-to-diameter ratio of the devices of the invention also has the advantage of increasing resistance to bending. Furthermore, the locking device of the present invention is lighter than conventional locking devices, making it more suitable for use in aircraft and automobiles.

The present invention has been described above in connection with embodiments, but
The present invention is not limited to the structure and form of the embodiments illustrated herein, but various embodiments are possible and various changes and modifications can be made without departing from the spirit and scope of the present invention. It will be obvious to those skilled in the art that additions can be made.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the locking device of the present invention, and FIG. 2 is an exploded view of the device of FIG. 12: Rod, 14: Housing, 16: Operation lever, 24: Rotatable bushing, 26: Fixed bushing, 30: Coil spring, 31, 32: Insertion part, 34, 36: Slot, 38, 39: Beveled surface ( (inclined cam surface), 40: sleeve, 42: collar,
45: Window.

Claims (1)

[Claims] 1. A mechanical friction locking device comprising: a housing; a rod disposed within the housing for axial movement relative to the housing; and an annular inner inclined cam surface. a first bushing having an annular inner inclined cam surface and being rotatably disposed with respect to the housing; It is disposed surrounding the rod between the inclined cam surfaces of the two bushings, and is attached at one end to the first bushing and at the other end to the second bushing. a coil spring operative to grip the rod to prevent movement of the rod; and a coil spring engaged with the second bushing through an opening formed in the housing to permit movement of the rod relative to the housing. and an operating member for rotating the second bushing to release the coil spring from the rod. 2. Claim 1, wherein one end of the first bushing and one end of the second bushing are brought into contact with each other.
Locking device as described in section. 3. The locking device of claim 1, wherein the first bushing and the second bushing include an extension defining a sleeve therebetween that encloses at least a portion of the coil spring. 4. The operating member includes a collar rotatably fitted over the housing, and an elongated member extending through an opening formed in the collar, the housing, and a second bushing, and connected to the second bushing. A locking device according to claim 1, which comprises: