US3544037A - Dampening device - Google Patents

Description

United States Patent 3,347,483 10/1967 Hoag Primary ExaminerLeonard D. Christian Attorney-Brown, Jackson, Boettcher and Dienner ABSTRACT: A dampening device particularly suited for tape tension levers of a tape recorder to prevent excessive tension in the tape which may occur, for example, in reel startups and stops. The dampening force is a combination of a frictional force and a spring force but only the difference in the two forces effects a return of the tension lever to its normal play range. A separate spring force is used in the play range to isolate reel vibrations or to accommodate minor fluctuations in speed of tape takeup. A retracted position of the levers is provided for loading of the tape and said position is controlled by the position of the switch actuator for the main on-off switch.

23 M He II fi lmmm\\\\\ '\\\\\i\ \\z \\l p Q r l Illl'l t- I i e i .32 r fu 1 5 "ll 36c 14 i Patented Dec. 1, 1970 Sheet I DAMPENING DEVICE BACKGROUND AND SUMMARY OF THE INVENTION Heretofore tape tension levers for tape recorders have frequently relied upon the tension, or compression, of a spring to relieve excessive tension on a tape. Such excessive tension may occur on startups when the supply reel is getting up to normal speed or if the takeup speed of the reel exceeds the speed at which the capstan can deliver tape. Also if there is substantial braking of the supply reel before the capstan drive is discontinued during a stopping operation, the tape may be placed under too much tension.

The disadvantage with prior art tension levers which rely upon springs is that, when the spring is tensioned during a lever tensioning movement as the lever yields in response to increased tensioning of the tape, greater and greater energy is stored in the spring. This energy is then subsequently released and frequently is released in a manner which results in a change in the tape speed so that a true recording or reproduction is not possible.

In my invention I employ one spring with each tape tension lever which spring is effective through a range of movement of the lever which I call the play" tension range, namely, a range of movement to accommodate minor changes in tape tensioning during a playing or recording operation when the tape and reels are up to normal speed. In this range the tape tensioning lever serves to filter out reel vibrations and accommodate minor changes in tape tension. This range of movement of the lever also can accommodate excess tape delivered during an initial startup when the capstan begins delivering tape and the takeup reel is first gaining speed.

Beyond this play range, I provide what I call a start-stop tension range since it is during starting or stopping that the tape may be excessively tensioned andit is on such occasion that it is necessary to have the tension lever yieldingly resist strong tensioning forces exerted on the tape. In this start-stop range, for example, it may take from to ounces of force to cause the tape tension lever to be moved through its range whereas in the play range one-fourth to 1% or 2 ounces may be all that is involved.

In the start-stop tension range I employ two structures which afford a combination of forces to produce the total dampening force on each tape tension lever, namely a combination of a frictional force and a resilient force provided by a second spring. I prefer to apportion these two forces so that the frictional force is a high percentage of the resilient force regardless of the variation in resilient force. When the tension lever is moved in the dampening direction in the start-stop range the combination of the frictional and resilient forces must be overcome, but only the difference in these forces serves to return the tension lever to the play range. Since that is a relatively small force, objectionable acceleration of the tape is avoided as the tape tension lever is returned to the play range.

In providing these two dampening forces I arrange the structures in such a manner that in the start-stop range the spring applies force to the friction-producing structure. The amount of frictional force is not dependent on the velocity of the tension lever or parts associated with it, but, instead, is determined by the amount the spring is tensioned. As the spring force increases, it applies increasing force on the frictionproducing structure and therefore the relation between the two dampening forces is kept substantially the same throughout the start-stop tension range.

Since in some types of tape recording activities there is a need for high tape speeds and instantaneous" starts and quick stops, the disadvantage of prior art structures, which rely solely on a spring, is apparent. Substantial energy will be stored in such spring which energy will be released as the tape tension lever is returned to the play range. In my dampening structure, high tensioning forces on the tape can be yieldingly accommodated but without permitting the energy storage in the spring to be directed completely to a return of the tension lever, since most of the stored energy must be employed in overcoming the frictional force which is only slightly smaller. As a consequence, the return of the tension lever to the play range is at a relatively steady and moderate rate which introduces no errors in recording or reproduction of information on the tape.

A further improvement provided by my invention is in the control of the tape tension levers during loading of the tape. Retraction means serves to hold the levers in an alined position while the tape is lead from the supply reel to the takeup reel past the heads, tape guides and tape tension levers.

Yet a further improvement resides in my provision of an onoff switch for the drive motor, with the switch and retraction means for the levers being jointly actuatable whereby the retraction means are released to their nonretracting position when the switch is actuated to its "on" position.

BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS FIG. 1 is a diagrammatic top plan view of a tape recorder which has a pair of tape tensionlevers which are dampened by the dampening device of my invention;

FIG. 2 is a view similar to FIG. I. but enlarged and fragmentary and partly broken away to expose portions of the tape tension levers and certain associated parts, with the tape tension levers shown in a retracted position suitable for loading of the tape;

FIG. 3 is a view similar to FIG. 2 but with different positions guide portion 13 of a tape tension lever 14 (FIG. 2) and past a series of tape guides 15a, 15b and 15c, capstan 16 and a head bar 17 carrying heads 18 and 19 and pressure roller 20. From there the tape 11 extends around a guide portion 13 of a second tape tension lever 14' (FIG. 2) and then to a takeup reel 21. Arcuate slots 22 and 22' are formed in the top plate 23a of the deck 23 (FIG. 2) and accommodate arcuate movement of the tape guides 13 and 13' of the tape tension levers 14 and 14'. As indicated by the legend on FIG. 1 the tape tension levers have a play" tension range and a start-stop tension range, a load position and, in the case of lever 14, an end-of-tape position. A switch actuator in the form of a control knob 24 controls the main on-off switch 25 (FIG. 2) and also, through structure to be described below, controls the load position of the tape tension levers 14 and 14'.

As may be seen from both FIGS. 2 and 3 the shaft 26, to which the control knob 24 is secured, is rotatable in a bracket 26a and is connected with a bellcrank lever 27, one arm 27a of which is pivotally connected with retraction means 28 for tape tension lever 14 and the other arm 27b of which is pivotally connected with retraction means 28 for tape tension lever The retraction means 28 and 28' are straps each having a body portion 28a with a slot 28!; adapted to be guided by pins 29 and 29 respectively. The pins 29 and 29' are supported from deck 23. Each retraction means also has a projection 280 at its end adapted to engage a short stud 14a of the tension lever 14 or 14'. Studs 14a are connected with the counterweight portions 14b of the tape tension levers and the levers are pivotally supported by their shafts for rotation in hollow bearing posts 14d (see FIG. 4) which posts are supported by the deck 23. Shafts 14c may be retained in position by snap rings 14f. A hollow stud lde positioned below each tape tension lever extends down around the hollow bearing post 14d and spring lever arms such as 30 and 30 are rotatably mounted on the lower ends of the hollow studs Me. Each of the tape tension levers 14 and 14' has a small down turned rotation of the spring lever arm or 30. l

The spring lever arms30 and 30. at their outermost ends have studs 31 and 31', respectively, which studs pass through arcuate slots 23b and 23c in the deck 23 and are pivotally secured as at 31a to movable members 32 and 32', respectively, in the form of dampening slides. It will be seen that if tape tension lever 14 rotates in a clockwise direction its flange 143 will engage the finger 30a of spring lever arm 30 and cause the latter to rotate clockwise and thereby cause movement of the dampening slide to the right as viewed in FIGS. 2 and 3. A

similar movement of dampening slide 32' to the left may take place in response to counterclockwise rotation of spring lever arm 30' and tape tension lever 14'. The other end of each slide has a slot 32a which fits about a yoke stud 33 and is slidable thereon and pivotally movable thereabout. Studs 33 and 33' are secured to the underside of deck 23.

Below the slides 32 and 32 there are mounted on the studs 33 and 33' yokes such as 34 and 34' each of which is pivotally swingable around its respective yoke stud 33 and 33'. The yokes are secured on thestuds by washers 35 and 35', respectively. Each yoke has a pair of spaced apertured flanges 34a and 34b for supporting a yoke pin 34c on which pin a pivotal member, such as bellcrank lever 36, is supported by a pair of spaced, apertured flanges 36a and 36b. integrally formed with the flanges 36a and 36b is one arm 36c of the bellcrank lever 36, the other am being designated by reference numeral 36d. At the outer end of the arm 360 are a pair of spaced flanges 36c and 36f which straddle the dampening slide 32. Accordingly, when the dampening slide is rotated around the yoke stud 33, it will cause the pivotal member 36 to pivot with it, which action is possible because member 36 is carried on the pivotal yoke 34 which is also mounted on yoke stud 33. Although I have described the foregoing structures by reference to the structure on the left side of FIGS. 2 and 3 it will be understood thatcorresponding structure and similar reference numerals are on the right side of F 16$. 2 and 3.

Spring means 37 in the form of a tensioned spring is connected at one end with the pivotal member 36 at an aperture 36g in arm 36d. A series of apertures similar to 36g may be spaced along the arm 36d to provide differing locations for connection of the spring 37 to the arm 36d of pivotal member 36 to vary the tension in the spring. The other end of spring 37 is secured in an aperture 32b in the bent end 320 of the dampening slide 32 which is rotatably mounted at 31a on the stud 31 of spring lever arm 30. The latter, inturn, is operatively associated with the tape tension lever 14. If preferred, the spring 37 could be formed of a plurality of shorter interconnected springs. Spring 37 is slightly tensioned and, when stretched, provides an increasing dampening force.

Frictional elements 38 and 38', each in the form of a frictional pad-which may be made of cork, cork and rubber composition, or some other suitable frictional material-are connected with the respective arms 36c of pivotal members 36 and 36'. Pads 38 and 38' engage the undersurface of the dampening slides 32 and 32' and are urged into engagement with the slides by the respective tension springs 37 and 37 pulling on arms 36d of pivotal members 36 and 36. On the opposite sides of the dampening slides 32 and 32 are disposed second frictional elements 39 and 39' each in the form of a washer (of the same or similar material as pads 38 and 38') which engages the dampening slide and the undersurface of the deck 23 and surrounds the stud such as 33 or 33.

Coil springs 40 and 40 have one end bearing against the spring lever arms 30 and 30' and the other end bearing against the body of the tape tension levers 14 and M, respectively, with the coils of the springs encircling the hollow studs Me. These springs 40 and 40' act to urge the spring tension levers 14 and M downwardly, or forwardly, as viewed in FIG. 1 of the drawings throughout a range of movement referred to as the play tension range. The force exerted by each of these springs'may be in the range of one-fourth l0 1% or 2 ounces. it is substantially less than the force of springs 37 and 37' which act on the tape tension levers 14 and 14 throughout the stop-start" tension range. Springs 37 and 37'. for example, may exert a force of from 10 to 20 ounces.

Spring as which urges the tape tension lever 14' in a clockwise direction permits the tape tension lever to accommodate an excess amount of tape which may be delivered when, for example, the tape recorder is started up and the capstan is immediately delivering tape before the takeup reel 21 reaches sufficient speed to take up the tape in the normal manner. Since the takeup reel does not go from zero speed precisely up to the desired takeup speed but,instead, will tend to exceed the desired speed at least momentarily after startup, then, immediately after tape tension lever 14 has taken up the excess tape delivered from the capstan 16, a condition will develop in which the takeup reel reaches a speed where it exceeds the speed at which the drive capstan i6 delivers tape. This will cause a tension in the tape and the tape will bear against the tape tension lever 14 and urge it into its startstop" tension range, whereupon lever 14 will engage and rotate spring lever am 30 which will in turn cause dampening slide 32' to be moved, spring 37 to be stretched and friction to be developed by the frictional elements 38' and 39 engaging the dampening slide 32' which is moving. The resulting dampening action will prevent the tape from being tensioned excessively. However, such-tension as develops has a braking effect on the takeup reel and may momentarily slow down the reel to a speed slightly less than the desired takeup speed, with the result that, momentarily, the amount of tape delivered by the capstan 16 may somewhat exceed the reels ability to take it up. Because the forces of spring 37 and the frictional elements 38 and 39 are cumulative in the dampening direction, but it is only the difference between the spring and frictional forces which will move the tape tension lever 14' back towards its play tension range, the action of spring 37 cannot be relied on alone to cause movement of tape tension lever 14' to absorb the excess tape since it might not be able to act quickly enough. However, tape tension lever 14', with the assistance of spring 40' can move quickly enough in a clockwise direction to take up the slack since tape tension lever 14' is not connected directly to slide 32' and to spring 37 and spring lever arm 30' but is merely in engagement with spring lever arm 30' through its bearing against the latters finger 300. When the foregoing condition of excess tape exists momentarily-and while spring tension lever 14 is taken it upthis results in less braking action on the takeup reel so that it can speed up to its desired speed. While it will be readily understood that there may be alternate conditions of underspeed and overspeed of the takeup reel 21 several times in the first moments of startup, these will not result in overtensioning of the tape or in significant fluctuations in speed of the tape past the heads 18 and 19, because the tape will be kept under tension, within a proper range, at all times.

During the playing or recording of the tape, tape tension levers l4 and 14' will have positions at or near their load positions and springs 40 and 40 will accommodate minor fluctuations in tape tension during tape takeup. However, when the tape has been played completely and the end of it has left the supply reel and it has passed from between the capstan 16 and pressure roller 20, it will no longer maintain a force against the tape tension lever 14', and spring 40' will cause the lever to move clockwise, as viewed in the drawings, to its most clockwise position (see end-of-tape position in FlGS. l and 3) at which time the stud 14a will rotate sufficiently clockwise to engage the switch arm 41a of the out of-tape switch 41 and move it counterclockwise to thereby open the switch and the circuit to the motor which drives the capstan, thereby shutting off the capstan motor, and also opening the circuit to motors associated with the takeup and supply reels and the circuit which holds the head bar 17 up against the tape. If the tape is then to be rewound onto the supply reel, or if a new tape is to be immediately played and the played tape removed, the user will turn the control knob 24 of the main on-off switch to the off position which movement will cause the retraction means 28 and 28', through their respective end projections 28c to engage the studs 14a of the tape tension levers l4 and 14' and rotate them to their load positions.

OPERATION Assuming that the tape recorder is in a shutoff condition, knob 24 of the main on-off switch will be so positioned that its shaft 26 and arms 27a and 27b of the bellcrank lever 27 will have moved the retraction means 28 and 28' to the position shown in FIG. 2. Arm 27b in such position will have pressed the switch contact arm 25a in a counterclockwise direction to thereby open the circuit. It will be further assumed that the controls (not shown) of the usual type for operating the tape recorder are in the stop position so the head bar 17 will be in its withdrawn position as shown in FIG. 1. The user will then dispose the tape 11 around the guide portion 13 of tape tension lever 14 and past the guides 15a, 15b and 150 and the capstan 16 and then around the guide portion 13' of tape tension lever 14' to the takeup reel. When the main on-off switch is actuated to on" position by turning the knob 24 clockwise as viewed in FIGS. 1 and 2, the retraction means 28 and 28 will be moved to their positions shown in FIG. 3 to permit the tape to be played. At this time springs 40 and 40' will be urging the tape tension levers l4 and 14' into engage ment with the tape 11.

When the play or record button or lever (not shown) is actuated, the head bar 17 is moved so that the heads 18 and 19 engage the tape and the pressure roller 20 engages the tape against the capstan 16. Tape 11 is then immediately driven to the right as viewed in FIG. 1 and tension is applied to the tape and the tape presses against the tape tension lever 14 through the latters guide portion 13 since the supply reel does not immediately come up to full speed. In this way a few inches of slack can be supplied, as the tape tension lever 14 yields, in order not to place the tape under undue tension. When the guide 13 of tape tension lever 14 is thus pressed by the tape 11 in a clockwise direction, the flange 14g at the counterweight end of the lever 14 engages the finger a of spring lever arm 30 and will thereby cause the spring lever arm 30 to rotate in a a clockwise direction and will thereby cause the dampening slide 32 to be moved generally toward the right with its slotted end 32a pivoting around the yoke stud 33 thereby causing the dampening spring 37 to be stretched. The foregoing parts provide a first dampening structure. A second dampening structure is provided by the dampening slides lower surface engaging the friction pad 38 which is being urged against it by the spring 37 acting through the bellcrank lever, or pivotal member, 36. The frictional element 38, along with the frictional washer 39, thereby introduces a frictional dampening force at the same time that a dampening force is provided by spring 37 which is being stretched as the dampening slide moves in its dampening direction in response to movement of the tape tension lever 14.

For purposes of maximum illustration, various positions of the tape tension levers l4 and 24' are shown in FIG. 3. The left side of that FIG. shows the tape tension lever 14 together with the associated first and second dampening structures, in their maximum dampening position, although this extreme position is not usually reached. At the right side of FIG. 3, the tape tension lever 14' is shown in full lines at a typical play position, but it will be understood that it also can be moved to a comparable maximum dampening position approximately 90 from the load position, or to some intermediate position in the stop-start tensioning range. Such dampening action may take place, for example, when the takeup speed exceeds the speed at which type is fed from the capstan.

FIG. 3 demonstrates the difference in tension provided by the springs 37 and 37' when in the substantially untensioned play position (right side of FIG. 3) and in the dampening position (left side of FIG. 3). As the tape tension lever M, or 14' is moved increasingly in the dampening direction, sometimes referred to as the first direction, the spring 37 or 37' becomes increasingly tensioned and therefore increases the dampening force. As can be readily seen from FIG. 4, the increase in tensioning of spring 37 causes it to act through the bellcrank lever 36 to also increase the pressure of the cork pad 38 against the dampening slide 32, thereby increasing the frictional dampening force as well. From this arrangement, it will be seen that the resilient, or spring, dampening force and the frictional dampening force will both increase and decrease together and the spring force is selected to be greater than the frictional force. It will be observed that a part of the frictional force provided by the dampening mechanism is provided by the frictional washer 39 which lies on the opposite side of the dampening slide 32 from the frictional pad 38. The total frictional force may, for example, be approximately percent of the spring force.

It is the difference between these two forces which then returns the tape tension lever in a relatively even and moderate manner to the play position. Were the tape tension lever to be dampened solely by a spring, it can be readily appreciated that the energy stored up in such spring could, when released, move the tape too rapidly. This could result in a failure to make a true recording or reproduction of information.

It is possible to vary the spring tension by substituting spring of different characteristics, but it is also possible to vary the spring force by connecting an existing spring at a different location along the arm 36d of the pivotal member (bellcrank lever) 36.

As can be seen from comparing the left and right side of FIG. 3, when the spring 37 is fully stretched the associated spring lever arm 30 has been rotated approximately 90 from its initial position which was like that shown on the right side of FIG. 3. During the time when spring lever arm 30 was rotating to the position shown on the left side of FIG. 3 and was moving slide 32 and thereby causing spring 37 to be stretched an increasing amount, the slide, 32 and spring 37 were pivoting around yoke stud 33 (see FIGS. 3 and 4) and swinging closer to the axis of rotation "of spring lever arm 30. As a result, toward the end of its rotation spring lever arm 30 moves slide 32 and stretches spring 33 at a slower rate. This provides a desirable dampening action without reducing the total dampening force, since the dampening force continues to increase (but less rapidly) by reason of the continuing stretching of the spring 37 and its action of increasing the frictional engagement of the pad 38 and washer 39 with the surfaces of the slide 32.

While I have shown a preferred embodiment of my invention, I do not intend to be limited thereto, except as the appended claims are so limited, since modifications will readily suggest themselves to one skilled in the art who has my disclosure before him.

I claim:

1. In a tape tensioning system having at least one tape tension lever, force producing means acting on said lever through one portion of its range of engagement with the tape, and second force producing means of a greater total strength acting on said lever through a second range of its engagement with the tape, the second force producing means including the combination of frictional force imparting means and resilient force imparting means separate from said first force producing means.

2. The invention of claim 1 wherein the tensioning system has a pair of tape tension levers each having the same kind of force producing means acting on it, together with lever retraction means adapted to hold said tape tension levers inan alined position during loading of the tape.

3. The invention of claim 2 together with an off-on switch and means for actuating the switch, said actuating means being operatively associated with said lever retraction means and adapted to actuate the lever retraction means to its retracting and nonretracting relationship with said tape tension levers.

4. The invention of claim 3 wherein said actuating means actuates the switch to .on position and actuates the lever retraction means at that time to its nonretracting position relative to said tape tension levers.

5. Dampening means for a movable device which is adapted to be engaged and moved in a first direction by force exerted by a tensioned tape, said dampening means comprising first and second structures, said first and second structures providing cumulative forces serving to dampen the movable device when it is moved in said first direction and providing differentially related forces when the force exerted by the tape is relieved for moving said movable device in a second direction.

6. Dampening means for a movable device as claimed in claim 5, said first structure providing a dampening force by frictional means and said second structure providing dampening force by resilient means.

7. The invention of claim 6 wherein the dampening force provided by the second structure is greater than the dampening force provided by said first structure.

8. The invention of claim 6 wherein the resilient means comprises a spring structure adapted to urge said movable member in a second direction when the force exerted by said tensioned tape is relieved.

9. The invention of claim 6 wherein the dampening force of said resilient means increases as said movable device is increasingly moved in said first direction.

10. The invention of claim 6 wherein the resilient means varies the dampening force of said frictional means as said movable device is moved.

11. The invention of claim 6 wherein the resilient means increases the dampeningeffect of said frictional means as said movable device is increasingly moved in said first direction.

12. The invention of claim 6 wherein the dampening force provided by the frictional means is a high percentage of the dampening force provided by the resilient means.

13. The invention of claim 6 wherein the dampening force provided by the frictional means is approximately 90 percent of the dampening force provided by the resilient means.

14. The invention of claim 6 wherein the rate of change of the total dampening force provided by said first and second structures decreases when the movable device is moving in said first direction and approaches its maximum displacement.

15. Dampening means for a movable device which is adapted to be engaged and moved in a first direction by a tensioned tape passing from a source of supply to a takeup device, said dampening means comprising a first structure and a second structure both serving to dampen movement of said movable device when it is moved in said first direction by force exerted by said tensioned tape, said first structure providing a dampening force by frictional means and said second structure providing a dampening force by resilient means, said first and second structures being effective through one range of movement of said movable device and said movable device having a second range of movement, together with second resilient means adapted to urge said movable device in a second direction in said second range of movement of said movable device.

16. The invention of claim wherein the average force exerted by said second resilient means in said second range of movement is less than a tenth of the average total dampening force provided by said first and second structures in the first range of movement of said movable member.

17. Dampening means for a tape tension lever which is movably mounted and has one end adapted to be engaged by a tensioned tape as it passes from a supply reel to a takeup reel, said dampening means comprising spring means having one end connected with a pivotal member and the other end connected with a movable member which moves in response to movement of said tension lever in a dampening direction, said movable member en.agin a frictional element during movement of said tension ever 0 thereby provide a frictional dampening force.

18. The invention of claim 17 wherein the tape tension lever causes movement of said movable member by pivoting a lever which is operatively associated with said movable member.

19. The invention of claim 17 wherein the movement of said movable member in the dampening direction stresses said spring means increasingly to provide an increasing dampening force.

20. The invention of claim 19 wherein the pivotal member, which is connected with the spring means, acts to press the frictional element and movable member increasingly into engagement with each other to increase the frictional dampening force.

21. The invention of claim 2i) wherein the frictional force is a high percentage of the spring force.

22. Dampening means for a tape tension lever which is pivotally mounted and has one end adapted to be engaged by a tensioned tape as it passes from a supply reel to a takeup reel, said dampening means comprising spring means having one end connected with a pivotal member and the other end connected with a movable member which moves in response to movement of said tension lever in a dampening direction, said movable member engaging a frictional element during movement of said tensioning lever to thereby provide a frictional dampening force, the movable member being a slide, and the pivotal member being another lever carrying the frictional element on one of its arms connecting with said one end of the spring by the other of its arms.

23. The invention of claim 22 wherein said one end of said spring is adapted to be connected to said one arm of the lever at any one of a plurality of locations along its length.

24. The invention of claim 22 together with a second frictional element engaging the slide on a side opposite from engagement with said first mentioned frictional element.

25. The invention of claim 22 wherein the lever which carries the frictional element has its fulcrum mounted for swinging movement around a support and said slide is guided by and has swinging movement around said support, with said fulcrum and slide swinging together.

26. The invention of claim 22 wherein said other end of the spring means connected with said slide follows a curved path and the effective length of said other lever acting on the slide to stress the spring means is reduced as the tape tension lever is increasingly moved in the dampening direction.

27. Dampening means for a movable device which is adapted to be engaged and moved in a first direction by force exerted by a tensioned tape, said dampening means comprising first and second structures, said first and second structures providing forces which add together to dampen movement of the movable device when it is moved in said first direction, one of said structures providing a further force moving said movable device in a second direction when the force exerted on the movable device by the tape is relieved and the other of said structures providing an opposing force to dampen the movement of said movable device in the second direction.

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