KR910005106B1 - Panel spring structrue for video cassette - Google Patents

Abstract

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Description

Leaf spring structures for magnetic tape cassettes, especially for video cassettes

1 is a schematic plan view of a leaf spring according to the invention.

2 is a longitudinal cross-sectional view of a leaf spring, the portion showing a spring with one fold and the portion showing a spring with two folds.

3 shows a leaf spring applied inside a video cassette in a resting state.

4 shows a leaf spring applied inside a video cassette in a state of use.

5 is a schematic plan view of a leaf spring according to the invention showing a portion having a projection of one type and a portion having a projection of a different or identical shape.

6 is a perspective view of a leaf spring having protrusions.

7 is a longitudinal sectional view of a leaf spring having protrusions.

8 is a cross-sectional view of a leaf spring having protrusions inserted into a video cassette in a resting state.

9 is a cross-sectional view of a leaf spring having protrusions inserted into a cassette in use.

* Explanation of symbols for main parts of the drawings

1: thin plate 2: end

3: through hole 5: kava

6: pivot 7: rile

10: fold line

The present invention relates to a leaf spring structure for a magnetic tape cassette, in particular for a video cassette.

As is known, video cassettes are currently used in the video cassette to engage a pivot configured on the axis of rotation of the tape feed rail.

In a conventional embodiment, the leaf spring is engaged with the inner surface of the cover at the intermediate portion and acts by elastic pressure contact with the pivot at the free end of the leaf spring.

Presently, leaf springs are manufactured according to a wide variety of configurations, ranging from elongated functional configurations to more recent configurations with substantially reduced extensions.

In all currently commercially available embodiments, the leaf springs, which appear to be edgewise, have a substantially curved, ie, piecewise configuration, with concave portions facing towards the feed rail.

According to a globally adopted standard, the leaf spring must have a form that acts on the rails with an elastic thrust in the contact pivot, which can be estimated at about 200 g for the VHS system at its moment of use.

In the above-described configuration, since the action and reaction points are simply constituted by the pivot for contact with the thin plate end and by the central portion of the thin plate connected to the cover, the point of contact with the thin plate in view of the static calculation of the force The force at is applied to the cover, which is equal to the sum of the two forces directed outwards of the cassette cover and against the sheet at the pivot, ie the outward thrust is about 400 grams for the VHS system. It acts on the cassette at the point where it is located.

When several moments are calculated, the maximum resistive moment is located at the point of contact with the cassette, that is, located in the center region of the elastic sheet, and decreases to zero at the point of contact with the pivot.

With this configuration of force, it is now necessary to use a spring with a high modulus of elasticity, and from a structural point of view, it is necessary to use a thin plate having a relatively large width and thickness and consequently consuming material for manufacture.

The object proposed by the present invention is to provide a plate spring bath body for a video cassette which fundamentally changes the conventional manufacturing category, and to reduce the width and thickness of the thin plate constituting the spring, the required elastic thrust against the pivot. By providing the possibility to act, it is intended to rule out the above mentioned disadvantages.

Within the above-described object range, the first object of the present invention is to obtain a component of the reaction force toward the inside of the cassette, so that the force of the force in the connection region of the leaf spring of the cassette cover with respect to the conventional leaf spring is It is to provide a leaf spring structure that allows the reverse in the reaction direction.

The second object of the present invention, in contrast to the prior art approach, has a reduced camber at rest before assembly in the cassette, i.e. a reduced distance from the rest surface at the center, and the requirement should have a high camber to have elastic properties. And, accordingly, to provide a thin sheet that needs to be stretched to prevent any jamming during assembly.

It is a third object of the present invention to provide a leaf spring structure, which significantly reduces all manufacturing steps, while producing with high quality properties.

It is a fourth object of the present invention to provide a leaf spring structure which can be easily obtained starting from commercially available materials, and which is simply free competition from an economic point of view.

The above and other objects, which will become apparent in the following, are achieved by a leaf spring structure for a magnetic tape cassette, in particular a video cassette, according to the invention, wherein the leaf spring structure is bonded to the cover of the cassette in the middle portion. At least one fold at the portion configured between the free end and the engaging region of the cover, with an elastic sheet having an elongated configuration as possible and acting on the central pivot of the magnetic tape feed rail in proximity to its free end A contact piece with the cover so that the fold line forms at least one support point for the elastic vibration of the sheet with the sheet of foil having a five-fold fractional line configuration with the elastic sheet inserted into the cassette. It is to be coupled by, the support point is the coupling spirit of the pivot and the cover It characterized by having the distance from the pivot of the small reels than the distance between.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Referring to the drawings, in particular FIGS. 1 to 4, a leaf spring structure for a magnetic tape cassette, in particular a video cassette, is generally provided with an elastic thin plate, denoted by reference numeral 1 and having a substantially extended configuration. do. Preferably, this structure consists of a strip of constant width rounded at its longitudinal end 2.

In the center part, it is preferably comprised by the through hole 3 for engagement with the member 4 for fixing to the cassette cover 5 to the elastic thin plate 1.

The thin plate is inserted into the cassette, connected to the cover 5 as described above, and acts on the pivot 6 of the rail 7 rotatably supported in a container 8, such as a video cassette. .

An important feature of the present invention is that the elastic thin plate 1, which appears to be an edge type, has a concave fractional line determined by the folded line 10, and the folded line 10 is connected to the free end of the spring and the cover. The dragon hole 3 is formed in the middle portion formed between the regions to be formed.

Considering the leaf spring for the VHS cassette, the distance between the rail pivots is about 92 mm, and for good results, by means of the folds 3, ie two fold lines 10 symmetrically arranged with respect to the joining area with the cover, The confined flat should be between 32 and 60 mm, that is to say on each of the two arms, and the fold line 10 should be spaced apart from the anchoring point of the cover, i.

In addition, it can be seen that by increasing the flat portion, the sheet thickness can be reduced while maintaining the same elastic properties.

From the experimental tests performed, it can be observed that by constructing substantially the fold line transverse to the longitudinal extension of the elastic sheet, at half the length between the contact point between the sheet and the pivot and the sheet's connection point to the cover. In other words, the best results are achieved.

As a specific application condition which maintains the above-described properties for functionality, the initial fold line preferably formed in close proximity to the hole 3 at a distance of about 1/6 of the distance between the hole 3 and the sheet end in contact with the pivot ( 20) it is possible to provide.

In the thin plate construction of this type, as shown more clearly in FIGS. 3 and 4, when the thin plate is introduced into the cassette, the fold line 10 is configured in contact with the inner surface of the cover and, in fact, the thin plate. A support point with a reduced lever arm for elastic vibration of the body.

Observing the diagram of the force, in the case of the VHS cassette, about 200 g of elastic thrust must be exerted on the pivot's 6 of the rail, so that the force in the support region determined by the point of contact of the fold line 10 is the cassette. While paralleled by a similar force directed outwards of, the coupling region, such as rivets, can be seen to actually reverse the force relative to the conventional method, since the force is directed from outside to inside.

In addition, in the contact area with the pivot 6, the thin plate is configured substantially parallel to the cover 5, whereby a force axially aligned with the rail 7 is applied.

Regarding the diagram for the moment, the maximum is substantially reached at the fold line 10 to a value significantly smaller than the maximum of the conventional leaf spring moment, since the lever arms are halved because the contained forces are equal.

The diagram of the moment is also reversed at the part constructed between the point of contact of the thin plate with the cover and the pivot region which will have the moment indicated opposite in the hole 3.

This is significant because it is possible by significantly reducing the moments to be balanced by the leaf springs, and the pivot of the rail, which significantly reduces the thickness and width, ie, significantly reduces the amount of material used to make the sheet. The elastic force acting on is the same as for the conventional method.

In order to achieve a reduction in the material used, the leaf spring structures for magnetic tape cassettes, in particular for video cassettes, as shown in FIGS. 5 to 9 are elastic in accordance with the invention, generally indicated by the reference numeral 100. With a thin plate, in a preferred embodiment the elastic thin plate has an elongated precipitant having a substantially constant width along its entire longitudinal extension.

The thin plate 100 can be inserted into the videocassette so that the free end of the rounded portion 102 constitutes a contact in the pivot 103 formed on the axis of the rail 104.

In the middle portion of the elastic thin plate 100, it consists of a through hole 105 into which the means for connection to the inner surface of the video cassette cover 106 can be coupled.

It is a feature of the present invention that the protrusions are configured on the sheet to reinforce the sheet to obtain the resilient thrust required for the rail, while also reducing the thickness of the sheet to reduce the material used. .

More specifically, the projection 11 extends in the longitudinal direction on the thin plate starting from the region where the hole 105 is formed and reaches close to the contact area with the pivot 103.

More specifically, the protrusions can be configured by a stamping operation to change the surface continuity and linearity according to the conventional scope, whereby significant reinforcement is achieved, thereby increasing the elastic properties. In a region having the largest protrusion in the region where the maximum moment of bending is applied, the protrusion may be configured to protrude from the surface facing the rail or to the opposite surface.

The protrusion preferably extends towards the ends in order to act on the pivot 103 because in a known manner the maximum stress generally occurs at the center of the sheet.

The projections in the region where the maximum moment for bending of the thin plates occurs are applicable to thin plates having any of the configurations currently adopted.

In order to increase the elastic properties of the thin plate as well, the thin plate is constructed with at least one foldability 120 at the portion comprised between the area where the hole 105 is formed and the contact end with the pivot 103, A concave fractional rail is constructed on the side facing 103).

In addition, the thin plate is composed of the protrusions by the protrusion 110 which reinforces it remarkably, and by the fact that it can be obtained with a metal material which is less expensive than stainless steel, it can achieve the intended functional requirements. It is possible to reduce the width as well.

It is therefore evident from the above that the present invention achieves its intended purpose, in particular with respect to conventional springs, which generally have a curved shape that substantially dissipates the force in the central region where the sheet is bonded to the cover. It constitutes a leaf spring having a fractional line configuration which distributes well.

In fact, commercially available Ad Fragmented Line Springs simply structurally simplify the curved springs because they do not form pivot points for any folded leading elastic vibrations.

In practice, the best results can be obtained using metal materials, but any shape as well as the materials and dimensions used can vary depending on the requirements.

Claims (14)

It is provided with an elastic thin plate 1 having an elongated configuration that can be engaged with the cover 5 of the cassette at its middle part and close to its free end 2 on the central pivot 6 of the magnetic tape feed rail 7. Concave piece rails having at least one fold line 10 in a portion formed between the free end 2 and the engagement region with the occa 5, for magnetic tape cassettes, in particular for video cassettes. A configuration is provided on the side facing towards the rail 7, and is brought into contact with the elastic thin plate 1 inserted into the cassette, and the supporting point is connected to the pivot 6 and the cama 5. A leaf spring structure, characterized in that it has a distance from the pivot (6) of the rail (7) less than the distance between the joining areas. 2. A leaf spring structure according to claim 1, characterized in that the thin plate (1) has a substantially constant width with respect to its entire longitudinal extension. The portion of the thin plate (1) formed between the fold line (10) and the coupling area of the cover (5) is between the coupling area of the cover (5) and the coupling point of the pivot (6). Leaf spring structure, characterized in that between 35% and 65% of the thin plate (1) portion formed in. 2. The leaf spring structure according to claim 1, wherein the fold line (10) is substantially constructed at half the distance between the engagement area with the cover (5) and the point of contact with the pivot (6). 2. A leaf spring structure according to claim 1, comprising an initial fold line (20) configured substantially in close proximity to the coupling area with the cover (5). 6. A plate according to claim 5, characterized in that the initial fold line 20 is substantially constructed at one sixth of the distance formed between the joining area with the cover 5 and the joining point with the pivot 6. Spring structure. 2. The leaf spring structure according to claim 1, wherein a force directed from the outside to the cover is applied to the cover in the joining region with the cover (5). It has an elastic thin plate 100 having an elongated configuration that can be engaged with the cover 106 of the cassette at its middle, and closes to its free end 102 on the central pivot 103 of the magnetic tape feed rail 104. In a magnetic spring cassette for a magnetic tape cassette, in particular a video cassette, a spring spring structure, the elastic thin plate 100 being positioned along at least one longitudinal portion in a region in which a maximum moment for bending of the thin plate 100 acts. Leaf spring structure, characterized in that it comprises at least one reinforcing projection (110) extending. 9. The leaf spring structure according to claim 8, wherein the projection portion (110) has a width that decreases toward the free end portion (102) starting from the joining region with the cover (106). 9. The leaf spring structure according to claim 8, wherein the protrusions (11) are obtained by plastic deformation of the material. The apparatus of claim 8, further comprising at least one fold line (120) formed by the protrusion (110) and configured at a portion configured between the free end portion (102) and the defect area of the cover (106). A line 120 is brought into contact with the cover 106 to form a supporting point against the elastic vibration of the thin plate 100 together with the elastic thin plate 100 inserted in the cassette, and the supporting point is And a distance from the pivot (103) of the rail (104) less than the distance between the pivot (103) and the engaging region of the cover (106). 12. The distance according to claim 11, wherein at least one fold line 120 of the thin plate 100 having protrusions 110 is configured between the engagement area with the cover 106 and the pivot 103 of the rail 104. Leaf spring structure, characterized in that substantially formed in half of. 9. The leaf spring structure according to claim 8, wherein said elastic thin plate (100) having protrusions (110) has a substantially constant width with respect to its entire longitudinal extension. 9. The leaf spring structure according to claim 8, wherein the elastic thin plate (100) having a protrusion (110) has a concave fragmentary line shape on a side facing the rail (104).

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