DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] As shown in FIGS. 2 to 13, a seat 10 of a tourist coach of the present invention comprises a cushion 11, a pair of backrests 12, a pair of bolsters 13, and a pair of armrest pads 14. The cushion 11 of the seat 10 has a width of double seat, and is elevated by a seat foot 15. The backrests 12 are perpendicularly joined with the rear end of the cushion 11. The backrest 12 has a width of single seat.

[0020] The bolster 13 also has a width of single seat. The bolster 13 has a front face 16 and a back face 17 as wide faces. The bolster 13 is joined on the backrest 12. The front face 16 has a concave arc portion 18, and the back face 17 has a slanting arc portion 19 tilting toward the adjacent bolster. When the cushion 11 is used for a double seat, the front faces 16 face forwards. When the cushion 11 is used for a single seat, the back faces 17 face forwards. If a single seat is to be formed, the bolsters 13 are turned 180 degrees, and the slanting arc portions 19 of the back faces 17 of the bolsters 13 are used as a special arc face. That is, the two bolsters 13 form a shape with a recessed middle portion. This describes the change from a double seat shown in FIG. 3 to a single seat shown in FIG. 4.

[0021] The armrest pads 14 have a pair of armrests 21 and a pair of pads 22. The armrests 21 are joined at two sides of the cushion 11. The armrests 21 can join the seat foot 15 if only the lower ends of the armrests 21 are fixed at appropriate positions. The pads 22 are joined on the armrests 21. The pads 22 have narrow face portions 23 and wide face portions 24. The pads 22 can be turned. When the cushion 11 is used for a double seat, the narrow face portions 23 face upwards. When the cushion 11 is used for a single seat, the wide face portions 24 face upwards.

[0022] As shown in FIGS. 5 and 6, a fixing device 30 is disposed between the bolster 13 and the backrest 12. The fixing device 30 comprises an insertion pole 31, a bushing 32, and a press fastener 34. The insertion pole 31 is joined at the center of the bottom face of the bolster 13. The bushing 32 is joined in the backrest 12. The insertion pole 31 is inserted into the bushing 32 and then positioned by the press fastener 34.

[0023] As shown in FIGS. 8 and 9, the bushing 32 does not protrude out of the top face of the backrest 12, and the press fastener 34 is joined at the upper end of the bushing 32. The press fastener 34 has an inner ring 35 and an outer ring 36. The inner ring 35 has a press head 37. The outer ring 36 has a through hole 38. The press head 37 protrudes out of the through hole 38. A small resilient part 39 is disposed between the inner ring 35 and the outer ring 36. The small resilient part 39 is a small spring. The small resilient part 39 is positioned at a gap 40 of the outer ring 36. The inner ring 35 can be used to lock an annular groove 41 of the insertion pole 31. If the insertion pole 31 has a plurality of annular grooves 41 thereon, the press fastener 34 can be used to adjust the position of the insertion pole 31, hence adjusting the height of the bolster 13. A miniature portion 33 is disposed near the lower end of the insertion pole 31. A main resilient part 42 is joined between the miniature portion 33 and the inner bottom face of the bushing 32. The main resilient part 42 is a compression spring. When the press fastener 34 releases its restriction to the insertion pole 31, the insertion pole 31 will automatically spring upwards to facilitate the adjustment of the bolsters 13 from a double seat to a single seat or vice versa.

[0024] The backrests 12 can be turned over. The mechanism letting the backrests be turned over is a standard equipment and has nothing to do with the present invention. The seat of the present invention is basically a double seat, and is primarily seated by two persons side by side. Each of the backrests has a hydraulic supporting structure for adjusting the slanting angle of the backrest. When the seat is used as a single seat, separate adjustment cannot be performed. The two backrests need to be adjusted together to let them move synchronously. One of the hydraulic supporting structures can be temporarily disabled. This control action can be performed and set by the driver or the carmen. Additionally, because the two backrests move synchronously, a joining device 25 is required to join the two backrests together so that they can be turned over simultaneously. As shown in FIG. 7, the joining device 25 is an inversely U-shaped fastener 26 inserted into the insertion holes 27 of the two backrests 12. However, the joining device 25 is not limited to the inversely U-shaped fastener. Any structure capable of joining the two backrests can be used as the joining device 25. If smoothness is required, a thin pad 28 shown as a dotted line in FIG. 6 can cover over the backrest.

[0025] As shown in FIGS. 11 and 12, a turn control device 50 is disposed in the armrest pad 14. The turn control device 50 can be used to let the pad 22 be turned within the range of 90 degrees. The turn control device 50 comprises an inner bushing 51 and an outer bushing 52. The inner bushing 51 joins the armrest 21, while the outer bushing 52 joins the pad 22. The outer bushing 52 is sleeved onto the inner bushing 51. The inner bushing 51 joins an annular sleeve 53 outside. The annular sleeve 53 has an embedding portion 54. The outer bushing 52 has a sleeving portion 55. The sleeving portion 55 and the embedding portion 54 are joined and positioned. A resilient part 56 in the inner bushing 51 can be joined at an appropriate position, preferably being the outer end face, of the outer bushing 52. The resilient part 56 is a long spring.

[0026] The turn control device 50 mainly exploits a dual bushing to support the pad 22. The outer bushing 52 and the pad 22 are connected together. The pad 22 can be pulled outwards to stretch the resilient part 56 so that the tooth-shaped sleeving portion 55 no longer tightly press the embedding portion 54 of the annular sleeve 53. Therefore, the outer bushing 52 can be turned. Because the narrow face portions 23 of the pads 22 face upwards when used for a double seat, the pads 22 can only be turned 90 degrees inwards and fixed there. The sleeving portion and the embedding portion are then joined together to facilitate the placement of the elbows of a passenger when used for a single seat. The use state of a double seat can be accomplished by reversing the above actions. The actions of turning over the bolsters and the pads shown in FIG. 13 are exploited to achieve free change between a double seat and a single seat.

[0027] To sum up, in the present invention, the bolsters and the pads of the armrest pads are exploited so that change between a double seat and a single seat can be accomplished with minimal actions. The double faces of the bolsters can be utilized so that the head of a passenger can be placed thereon more comfortably. The bolsters are matched with the positioning of the press fasteners so that both the use states of a single seat and a double seat can be accomplished. Additionally, the turn of the pads can be exploited to shrink part space of the cushion so that a passenger can seat more comfortably on the seat used as a single seat.

[0028] Although the present invention has been described with reference to the preferred embodiment thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and modifications have been suggested in the foregoing description, and other will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.