Unitary body for mounting tape transport elements

A unitary guide body which includes structural elements for tape loading and unloading, particularly for use in a VCR deck, which is constructed to include as a part of the unitary guide body a pair of guide grooves for guiding a pair of slant bases acting to load a tape to a drum, a guide groove formed adjacent to one of the slant base guide grooves for guiding a tape guide roller, stoppers disposed adjacent to leading ends of the guide groove to position the slant bases and the guide roller, a drum receiving recess for slantly mounting a drum at an inclination angle of a given angle, a plurality of drum fastening holes, a shaft for an I-shaped roller, and a main slant post, which provide for an enhanced production rate of the elements forming parts of the unitary guide body while overall product quality is maintained.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a tape transport and guide structure for a video 
cassette recorder (VCR), which transports a tape and positions a drum in a 
tape loading and unloading apparatus of the VCR, which transfers the tape 
in a cassette to bring it into and out of engagement with the drum. 
2. Description of the Prior Art 
Generally, a drive mechanism of a tape loading and unloading apparatus 
which brings a tape for a video cassette recorder(VCR) into and out of 
engagement with a drum is of any one of two types: a ring type utilizing 
two rotary rings and a cam type utilizing cams. The conventional tape 
loading apparatus of a VCR deck, which has the ring type drive mechanism 
commercially available from Gold Star Co., Ltd. in Korea, under Model NO. 
GS-CIP is in the form as shown in FIGS. 3 to 5 of the accompanying 
drawings, which comprises a pair of slant bases (2) each having a guide 
roller(1) and disposed on a guide rail(4) for movement along a pair of 
guide grooves(3) of the rail, V-shaped stoppers(5) functioning to stop the 
movement of the slant bases(2) along the guide grooves(3), thereby 
determining a final position of the tape, a drum base (not shown in FIG. 3 
because it is located under a drum(6) slantly supporting the drum(6) at an 
incline of a given angle, a main slant post(7) turning round the drum, and 
a main slant post stopper(8) having a stopping groove (8a) for receiving 
the main slant post(7). In addition, a pair of support shafts (9a, 9b) 
defining a reference plane for a cassette are fixedly mounted on a main 
base of the deck, on which the drum base is disposed, at positions 
adjacent to the tape supply and take-up reels, respectively. 
With the construction having such principal elements, as can be seen in 
FIG. 4 showing a tape transport system, the tape(10) is brought into 
engagement with the drum(6) by the movement of the guide rollers(1) 
mounted on the slant bases(2) from stationary positions shown in FIG. 3 to 
positions in FIG. 4 along the guide grooves(3) of the guide rail(4) and 
the movement of the main slant post(7) round the drum. In this loaded 
state, a picture can be recorded on the tape through the drum, or a 
picture previously recorded on the tape may be played back. 
At this point, the turning movement of the main slant post causes the tape 
to be passed through the drum at a given angle which is kept in a 
vertically oriented posture by means of a main slant post turning 
mechanism as shown in FIG. 5. More specifically, when the driving force of 
a loading motor (not shown) is transmitted to a loading gear(11), the gear 
rotates a cam gear(13) through a connecting gear(12) interposed between 
them. At this time, since a pin(17) of a lever cam(14) is received in a 
curved groove (13a) formed in the cam gear(13) to be slidingly movable 
along the groove, the rotation of the loading gear(11) leads to 
counterclockwise rotation of a lower toothed end(14a) of the lever cam(14) 
through a series of gears comprising the loading gear(11), the connecting 
gear(12), the cam gear(13) and the lever cam (14), thereby resulting in 
clockwise rotation of a gear(16) of a post arm(15), which is engaged with 
the toothed end(14a). As a result, the post arm(15) is rotated from a 
position as indicated by the two-dot-and-dash lines in FIG. 5 to a 
position as indicated by the solid line, so that the main slant post (7) 
fixed to a free end of the post arm(15) is moved toward and received in 
the stopping groove(8a) of the main slant post stopper(8), thereby guiding 
the travel of the tape. 
During the turning movement of the main slant post, a pair of the slant 
bases(2) movable along the guide grooves(3) are also moved from a stop 
position of the guide rail as shown in FIG. 3 to a position of the 
V-shaped stopper mounted on the drum base along a pair of the semicircular 
guide grooves (3) formed in the guide rail(4) by means of a loading 
mechanism (not shown), whereby the guide rollers(1) on the slant bases(2) 
bring the tape into engagement with the drum(6). The other of the V-shaped 
stoppers (5) functioning to stop the movement of the slant bases is not 
shown in FIG. 3 because it is positioned behind the drum(6). 
In the cam type drive mechanism (commercially available from SONY Company 
in Japan, under Model No. TR-55) other than the above described ring type 
drive mechanism acting to load the tape by means of the rotary ring gear, 
the basic operation of loading and unloading the tape us substantially the 
same as that of the ring type. The cam type is, however, different from 
the ring type in that the former utilizes a cam gear and a folding lever 
for moving the slant bases so as to engage the tape with the drum, in 
place of the ring gear of the latter. In addition, the cam type drive 
mechanism does not carry out the turning movement of the main slant post 
by the post turning mechanism as described above, but utilizes a main 
slant post fixedly mounted at a given angle and a separate tape guide 
roller movable along a guide groove formed in a guide rail in order to 
permit the tape passed through the main slant post via the guide roller to 
be maintained in a vertically oriented posture. 
As described above, both the ring type and cam type drive mechanisms are 
complex in construction, requiring a plurality of parts. More 
particularly, the ring type drive mechanism comprises a plurality of 
parts, such as the guide rail for guiding the moving slant bases, the drum 
base for mounting the drum, the V-shaped stoppers, the movable main slant 
post, the support shafts for supporting the cassette, and the main slant 
post turning device, all of the them being mounted on a main base, while 
the cam type drive mechanism comprises a plurality of parts, such as the 
guide rail for guiding the moving slant bases, the stoppers mounted on the 
guide rail, the drum base for mounting the drum, the fixedly mounted main 
slant post, and the tape guide roller movable on the guide rail, all of 
them being individually mounted on a main base. As a result, finishing and 
assembly errors of the respective parts may adversely affect stability of 
the entire tape transport system and product quality. Further, the 
requirement for a plurality of the elements results in complicated, 
tedious assembly work and lower manufacturing efficiency. 
SUMMARY OF THE INVENTION 
With the foregoing problem of the prior art in view, it is an object of the 
present invention to provide a tape transport and guide structure for a 
video cassette recorder, comprising a unitary guide body into which a 
plurality of parts as described above are integrated. 
To achieve the above object, there is provided according to the present 
invention a tape transport and guide structure for a video cassette 
recorder, comprising a unitary guide body which is provided with a pair of 
guide grooves for guiding a pair of slant bases acting to load a tape to a 
drum, a guide groove formed adjacent to one of the slant base guide 
grooves for guiding a tape guide roller, stoppers each disposed adjacent 
to each of leading ends of the guide grooves to position the slant bases 
and the guide roller, a drum receiving recess for slantly mounting a drum 
with an incline of a given angle, a plurality of drum fastening holes, a 
pair of support shafts for defining a reference plane for a cassette, a 
shaft for mounting an I-shaped roller, and main slant post.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 1 and 2 which respectively illustrates plan and 
perspective views of an integral tape guide structure according to the 
present invention, a preferred embodiment of the invention provides 
improvements in a drive mechanism of a cam type of the conventional ring 
and cam types as described aboved. 
First, as shown in FIG. 2, the integral guide structure of the present 
invention comprises a guide body(20) formed entirely of unitary casting 
and provided at its central portion with a drum receiving recess(21) for 
seating a slantly mounted drum conforming to a predetermined angle of 
inclination of the drum, and a plurality of holes(22) for fastening the 
drum. There are also formed on the opposite sides of the drum receiving 
recess(21) a pair of guide grooves(23) for guiding slant bases movable to 
load a tape. One of the guide grooves (23) right groove in FIG. 2) has an 
inclined end distal to the drum receiving recess for slantly traveling the 
tape. In addition, stoppers(24) are each disposed adjacent to each of 
leading ends of the guide grooves(23) to stop the slant bases moving along 
the guide grooves, thereby bring the tape into engagement with the drum. 
Further, there are provided on a right side portion of the guide body(20) 
adjacent to the one of the guide grooves(23) a guide groove(26) for 
guiding a guide roller(33)(see FIG. 1) moving toward a main slant 
post(25), and another stopper(27) located adjacent to a distal end of the 
guide groove(26) to stop the movement of the guide roller. The main slant 
post(25) is fixedly mounted with an incline of a given angle at a position 
near an upper end portion (as viewed in the drawing) of the guide 
groove(26). Also a shaft for mounting an I-shaped roller(28) for guiding 
the travel of the tape being fed from a tape supply reel is disposed 
adjacent to the other of the guide grooves(23). Therefore, principal 
elements of a tape loading and unloading mechanism functioning to bring 
the tape into and out of engagement with the drum perform the operation of 
guiding the travel of the tape in combination with the unitary guide 
body(20) as shown in FIG. 2. 
The traveling condition of the tape(10) loaded to the drum(6) on the guide 
body(20) of the invention is shown in FIG. 1. The tape(10) being fed from 
the supply reel(30) passes in order through the I-shaped roller(28) 
mounted on the integral guide body(20), one of rollers(32) of the slant 
bases(31) moved along the guide grooves(23) and then stopped by the 
stoppers(24), the drum(6), and the other of the rollers(32) of the slant 
bases(31). Then, the tape(10) passes through the guide roller(33) moved 
along the guide groove(26) to the distal end of the groove, and then is 
wound on a take-up reel(40) via the main slant post(25) and other guide 
rollers(29a, 29b, 29c). Briefly described again, in the loaded condition, 
the tape travels along the path comprising the supply reel(30), the 
I-shaped roller(28), the roller(32) of the supply side slant base, the 
drum(6), the roller(32) of the take-up side slant base, the guide 
roller(33), the main slant post (25), the guide rollers(29a, 29b, 29c), 
and the take-up reel (40). 
As described above, according to the present invention, since the shaft for 
mounting the I-shaped roller for guiding the travel of the tape, the guide 
grooves for guiding a pair of the slant bases, the drum receiving recess 
for mounting the drum, the guide groove for guiding the tape guide roller, 
and the stationary main slant post are integrally provided on the unitary 
guide body, finishing and assembly errors which are liable to occur in the 
prior art apparatus comprised of a plurality of parts may be considerably 
diminished, resulting in enhancing stability of performance of the tape 
transport system and product quality. 
In addition, the unitary guide body of the present invention enables to 
simply assemble a semiassembly of the elements to the main base, thereby 
greatly simplifying a assembly task. Furthermore, the unitary guide body 
of the invention is also applicable to the ring type drive mechanism other 
than the cam type described above as a preferred embodiment of the 
invention, and may be variously modified to be applied to magnetic 
recording apparatuses, such as a DAT (Digital Audio Tape) player, or the 
like functioning similarly to the VCR without departing from a basic 
concept of this invention. 
Having described but a single embodiment of this invention, it will be 
apparent that many changes and modifications can be made therein without 
departing from the spirit and scope of the invention as defined in the 
appended claim.