Pole base assembly driving device for tape recorder

A pole base assembly driving device for a tape recorder is disclosed. Manufacturing of decks becomes simpler and at lower cost. The pole base assembly driving device has a loading gear rotatably disposed on the deck, and rotated by a driving force which is transmitted from a driving source installed on the deck. The pole base assembly further comprises an elastic rod connected by one end to the loading gear, and connected by the other end to a link member which is connected with the pole base assembly. The elastic rod is preferably made of a material which is elastically bendable by an external force, and preferably comprises a deformation restricting means for restricting a deformation of the elastic rod when the elastic rod is deformed by the rotation of the loading gear, such as protrusions on the concave side of the rod when deformed and a reinforcement member. As a result, the number of parts and manufacturing cost is reduced, and deterioration of durability due to breakage of parts can be avoided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit under 35 U.S.C. § 119(a) from Korean Patent Application No. 2002-86840 filed on Dec. 30, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a tape recorder, and more particularly, to a driving device for moving a pole base assembly along a deck so as to move a magnetic tape into and out of close contact with a head drum during magnetic tape loading and unloading.

2. Description of the Related Art

Generally, tape recorders such as a video tape recorders (VTR), camcorders, and the like, have deck mechanisms to record and reproduce data as a magnetic tape runs along a predetermined path defined inside the deck.

FIG. 1illustrates one example of a moving deck100, which is typically employed in the tape recorder. The deck100of the tape recorder includes a pair of pole base assemblies140, and a driving device for moving the pole base assemblies140along a guide rail130of the deck100during the loading or unloading of the magnetic tape.

Each of the pole base assemblies140includes a base member141slidably connected with a guide rail130, a pole member145protruding from an upper surface of the base member141and/or a roller member144. While the guide rail130is depicted as being integrally formed with the head drum base120, which is for seating the head drum110on the deck100, many other variations are available for the structure of the guide rail130, as will be appreciated by one of ordinary skill in the art.

As shown inFIG. 2, the pole base assembly driving device150includes first and second loading gears153a,153b, and first and second link members155a,155b.

The first and the second loading gears153a,153bare disposed on the deck100to correspond to the pair of pole base assemblies140, respectively, and are driven by the force which is transmitted from a loading motor151(FIG. 1) via a predetermined gear train including a main gear152(FIG. 1).

The first link member155ais rotatably connected at one of its ends to the base member141of the pole base assembly140. The second link member155bis rotatably connected at both of its ends to the other end of the first link member155aand to the loading gears153a,153b, respectively. As a result, the pole base assemblies140are moved along the guide rail130in association with the rotation of the loading gears153a,153b.

In order to ensure stable data recording or reproducing with respect to the magnetic tape (not shown), during the loading of the magnetic tape, the pole base assemblies140should be in close contact to the terminal end of the guide rail130toward the head drum110, and should also maintain the close contact stably.

To this end, conventionally, the loading motor151has been driven for an extra time after the pole base assemblies140have contacted the end of the guide rail130toward the head drum110so as to rotate the loading gears153a,153bfor a predetermined rotation angle.

However, this way causes excessive pressure on the link members155a,155bwhen the loading gears153a,153bare driven past that the point at which the pole base assemblies140have contacted the end of the guide rail130. Also, as the loading and unloading of the magnetic tape is repeated, such over pressure is repeatedly exerted on the link members155a,155b, causing the link members155a,155bto break and subsequently, causing the durability of the deck100to degrade.

In order to solve the above-mentioned problem, conventionally, the pole base assembly driving device150added torsion springs (S) inside the loading gears153a,153b, respectively, as shown inFIG. 3. The torsion springs (S) are disposed to surround the axes153cof the loading gears153a,153b. The torsion springs preferably have one end fixed to an inner sidewall of the loading gear153a,153band the other end fixed to the second link member155bwhich is pivotally connected to the loading gear153a,153b.

By this structure, as the loading gears153a,153bare rotated past the point at which the pole base assemblies140are in contact with the end of the guide rail130toward the head drum110, the loading gears153a,153bcan be elastically rotated with respect to the second link member155bwithin the movement range permitted by the torsion springs (S). Accordingly, the pole base assemblies140are in close contact with the end of the guide rail130, and stay in close contact by the recovery force of the torsion springs (S).

Recently, demand for compact-sized tape recorders has been increasing, and accordingly, components of smaller size and less number are required. However, because the conventional tape recorder requires the loading gears153a,153band the second link member155bto be pivotally connected with the loading gears153a,153b, and also requires torsion springs (S) for the loading gears153a,153b, the manufacturing process is relatively complicated and lots of components are required for assembly.

SUMMARY OF THE INVENTION

Accordingly, it is an aspect of the present invention to provide a pole base assembly driving device which requires fewer components and thus has a simpler manufacturing process. It is a further aspect of the present invention to provide a pole base assembly driving device which is capable of elastically moving a pole base assembly to the end of a guide rail tightly during loading of a magnetic tape.

In an effort to achieve the above aspects and other features of the present invention, a pole base assembly driving device for a tape recorder includes a loading gear which is rotatably disposed on a deck and rotated by a driving force from a driving source mounted on the deck. The pole base assembly driving device also includes an elastic rod which is connected by one end to the loading end and to a link member by the other end. The link member is connected with the pole base assembly. The elastic rod is made of a material which is elastically bendable by external force.

Further provided is a deformation restricting means, which restricts inelastic deformation of the elastic rod by restricting bending deformation of the elastic rod to an extent that the elastic rod is deformed to a predetermined shape.

According to the present invention, a number of additional parts such as a torsion spring can be omitted, and the manufacturing process can be simplified. Also, the cost of manufacture advantageously decreases. Further, by restricting inelastic deformation of the elastic rod by the compression load during loading and unloading of the magnetic tape, reliability of the deck is improved.

The deformation restricting means preferably includes a plurality of protrusions which are protruded from the side of the elastic rod approximately at the center portion of the elastic rod, and spaced from each other along a length of the elastic rod.

The protrusions are protruded from a side of the elastic rod which is inwardly (concavely) curved during the deformation of the elastic rod.

When the elastic rod is deformed to the predetermined shape, the protrusions restrict extra deformation of the elastic rod beyond the predetermined shape by contact between leading ends of respective protrusions.

The elastic rod and the protrusions are preferably integrally formed with each other, and the elastic rod and the loading gear are preferably integrally formed with each other by molding of synthetic resin material.

Meanwhile, the deformation restricting means also preferably includes an elastic reinforcement member which reinforces the elastic recovery force of the elastic rod during the unloading of the magnetic tape.

The elastic reinforcement member is preferably an iron core which is disposed across the length of the elastic rod.

Throughout the drawing figures, it should be understood that like reference numerals refer to like features and structures.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Throughout the description, elements having the same construction and function as those of the conventional tape recorder as described above with reference toFIGS. 1 to 3will be referred to by the same reference numerals, and further description thereof will be omitted.

Referring toFIG. 4, a pole base assembly driving device250for a tape recorder according to an embodiment of the present invention includes a pole base assembly140, first and second loading gears253,254, two elastic rods255and two link members155.

More specifically, a pair of pole base assemblies140are slidably provided to a pair of guide rails130which are formed adjacent to left and right portions of a head drum110(FIG. 1). Each pole base assembly140includes a base member141which is slidably disposed on the guide rail130. At least one pole member145and/or a roller member144are formed on the upper surface of the base member141. A link member155is hinged to the lower surface of the base member141. Meanwhile, the guide rails130are preferably integrally formed on a head drum base120(FIG. 1) on which the head drum110is seated. It should be understood that the construction of the guide rail130is not limited to the same depicted in this embodiment, but rather can be modified appropriately in accordance with the type of the deck100employed.

The first and second loading gears253,254are rotatably disposed on the head drum base120and correspond to the pole base assemblies140, respectively, and are rotatably driven by the force which is transmitted from the loading motor151(FIG. 1) via the gear train including the main gear152(FIG. 1). According to an embodiment of the present invention, the first loading gear153is engaged with the main gear152, and is driven by the force transmitted from the loading motor151via the main gear152. Also, the second loading gear254is engaged with the first loading gear153, and is driven by the force transmitted from the main gear152via the first loading gear253. To this end, the first loading gear253has a dual-gear structure consisting of a gear part tooth-engaged with the main gear152, and another gear part tooth-engaged with the second loading gear254. Again, the structure of the first loading gear253is modifiable depending on the type of the deck100as employed. Generally, the loading gears253,254are formed of metal material, but it is preferable to form the loading gears253,254with a material which is inexpensive and allows easy shaping. For example, the loading gears253,254may be formed by a molding with a synthetic resin material. The loading gears253,254are connected to the pole base assemblies140through at least one link member, and in the present embodiment, the loading gears253,254are connected to the pole base assemblies140through the link member155and the elastic rod255.

FIG. 5illustrates the second loading gear254and an elastic rod255as shown inFIG. 4. Referring toFIG. 5, the elastic rod255is preferably integrally formed with the second loading gear254. Accordingly, as the elastic rod255is protruded from a side of the second loading gear254, one end of the elastic rod255is fixed to the second loading gear254, while the other end is hinged to the link member155(FIG. 4). Accordingly, substituting for the conventional second link member155b(FIG. 2), the elastic rod255pivotally connects the second loading gear254with the link member155. It is preferable that the elastic rod255is made of a material which is elastically bendable by an external force. Accordingly, the elastic rod255is bent by the pressure which is generated when the second loading gear254is further driven in the magnetic tape loading direction after the pole base assemblies140have contacted the end of the guide rails130toward the head drum110. The elastic rod255is preferably made by a molding of synthetic resin material. In this case, the elastic rod255can advantageously be formed in the process of forming the second loading gear254.

The technical structure of the first loading gear253and the elastic rod255is similar to that of the second loading gear254and the elastic rod255as described above with reference toFIG. 5. Accordingly, the description thereof will be omitted.

Further provided is a deformation restricting means, which prevents inelastic deformation of the elastic rod255. In the present embodiment, the elastic rod255is deformed by the loading gears253,254only to a predetermined shape. To this end, the deformation restricting means of the present embodiment includes a plurality of protrusions256formed on the elastic rod255. Preferably, the protrusions256are integrally formed with the elastic rod255. Accordingly, the elastic rod255, the protrusions256and one of the loading gears253,254can advantageously be integrally formed by a molding of a synthetic resin material which is easy to form and also inexpensive.

The protrusions256are formed approximately on the middle side of the elastic rod255, and at predetermined intervals from each other along the lengthwise direction of the elastic rod255. More specifically, the protrusions256are formed on a side of the elastic rod255, which is concave when the elastic rod255deforms. Further, the protrusions256preferably take the form of ribs on the elastic rod255. The protrusions256are formed at intervals along the length of rod255, which allow the protrusions256to contact respective neighboring protrusions256at the leading ends when the elastic rod255is deformed to the predetermined shape by the rotation of the loading gears253,254. Because the leading ends of the protrusions256contact each other, further undesired deformation of the elastic rod255can be avoided.

There is an iron core257functioning as an elastic reinforcement member for the elastic rod255so as to allow the elastic rod255to return to its original shape more easily during the unloading of the magnetic tape. The iron core257is seated on a seating groove257awhich is defined in the outer circumference of the elastic rod255so that the iron core257is disposed in the elastic rod255with its lengthwise direction parallel to the lengthwise direction of the elastic rod255.

The operation of the pole base assembly driving device250according to an embodiment of the present invention will now be described in greater detail. As shown inFIG. 6, with the loading of the magnetic tape, the main gear152is rotated in the ‘B’ direction by the driving force transmitted from the loading motor151(FIG. 1). Accordingly, the first loading gear253is rotated. The second loading gear254is also rotated in association with the first loading gear253. Accordingly, the pole base assemblies140, which are connected with the first and the second loading gears253,254via the elastic rod255and the link member155, are moved to the ends of the guide rails130(FIG. 4) toward the head drum110(FIG. 1).

When the pole base assemblies140contact the ends of the guide rails130toward the head drum110, the pole base assemblies140are prevented from moving further. However, the main gear152is rotated an extra rotation angle to tightly contact the pole base assemblies140against the ends of the guide rails130. As a result, the first and second loading gears253,254are further driven.

As the first and second loading gears253,254are rotated, pressure is exerted inside the elastic rod255. Accordingly, as shown inFIG. 7, the elastic rod255is elastically bent to tightly contact the pole base assemblies140to the ends of the guide rails130, while also elastically supporting the pole base assemblies140. The elastic rod255is bent by the rotation of the loading gears253,254. As the rotation of the loading gears253,254exceeds a predetermined range, the protrusions256on the side of the elastic rod255contact with each other, thereby preventing further bending of the elastic rod255. As a result, inelastic deformation of the elastic rod255due to excessive bending is avoided.

During the unloading of the magnetic tape, the loading gears253,254are rotated in the reverse direction (B,FIG. 6). Accordingly, the elastic rod255is subject to a recovery force and returns to its original shape. At this time, as the recovery force of the iron core257adds to the recovery force of the elastic rod255, the elastic rod255returns to its original shape more quickly.

While the present invention has been described as above with reference to a particular embodiment, this example should not be considered limiting. That is, the present invention can also be applied to other types of tape recorders such as a video tape recorder (VTR) and the like which has a loading gear rotating in the loading of magnetic tape by an extra rotation angle after the pole base assemblies are contacted at the ends of the guide rails, and a link member pivotally connecting the loading gear with the pole base assemblies.

According to the present invention as described above, instead of a conventional second link member and torsion springs, an elastic rod, which is integrally formed with a loading gear and elastically deformable by an external force, is used. As a result, time for assembling the deck is reduced, and the assembly process becomes simpler.

Further, the pressure exerted on the elastic rod due to excessive rotation of the main gear can be absorbed by the elastic bending of the elastic rod, and also the inelastic deformation of the elastic rod can be prevented due to the presence of protrusions on the side of the elastic rod and the iron core. As a result, the durability of components is prolonged, and the product reliability is ensured even for frequent loading and unloading of the magnetic tape.