Abstract:
A grill comprises an upper shell, a lower shell, an upper grill pan disposed on the bottom surface of the upper shell and a lower grill pan disposed on the top surface of the lower shell, wherein the upper shell connects to the lower shell by hinge mechanisms such that the distance between the two grilling pans is adjustable to accommodate to-be-grilled food items of varying thickness.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a grill, more particularly to a grill with adjustable grilling space. 
     RELATED ART 
     Common grill usually comprises an upper grill pan and a lower grill pan that is pivoted to the upper grill pan. The food is laid between the two grill pans to be cooked. Such a grill is acceptable for grilling lamellar foods. But when thick food or lumpish food are placed between the two grill pans, the front side of the upper grill pan will incline upwards, and as a consequence the two grill pans will form an angle, resulting in the rear part of the food item to be burnt due to being clamped too tightly while the front part of the food is undercooked due to not being clamped firmly. 
     To overcome the problem, grills have been designed with adjustable distance between the upper grill pan and the lower grill pan. A common design for this type of grills uses a U-shaped pan support on the lower grill pan, wherein the rear ends of the two side poles of the pan support are pivoted to the two rear corners of the lower grill pan; the front side pole of the grill pan forms a handle; the middle of the two sides of the upper grill pan is pivoted to the insides of the middle of the two side poles of the U-shaped pan support; and the upper grill pan can turn relatively to the pan support by the axis of the connecting line between the two pivot points. The U-shaped pan support can move up and down following the changing distance between the upper grill pan and the lower grill pan, yet the upper grill pan remains parallel to the lower grill pan by turning relatively to the U-shaped pan support. Grills of the above design, however, still have many disadvantages. For example, when the distance between the upper grill pan and the lower grill pan increases, although the upper grill pan can remain parallel with the lower grill pan, the lower grill pan is moved off its vertical position. The bigger the distance between the upper grill pan and the lower grill pan, the greater the displacement of the upper grill pan off its vertical alignment with the lower grill pan. In other words, in order to accommodate thicker food times, vertical alignment between the upper grill pan and the lower grill pan is sacrificed. 
     The present applicant has also filed a Chinese patent application, number 200520125193.X, entitled “A grill with liftable top cover,” which discloses a grill that comprises an upper shell, a lower shell, an upper grill pan embedded into the lower surface of the upper shell and a lower grill pan embedded into the upper surface of the lower shell. The back side of the lower shell has a connecting piece that can move up and down. The upside of the connecting piece protrudes above the lower shell and is pivoted to the back side of the upper grill pan. The lower shell has an elevator mechanism that is connected to the connecting piece and drives the connecting piece to move up and down as well. The distance between the upper grill pan and lower grill pan can be adjusted by the elevator mechanism. However, the elevator mechanism has high production cost, and the elevator mechanism tends to breakdown easily under the weight of the upper grill pan. 
     Furthermore, with the same grill, users may need to change different grill pans with different depths for adjusting grilling space. If the distance between the upper grill pan and the lower grill pan can&#39;t be adjusted or the upper grill pan and the lower grill pan can&#39;t be aligned at vertical direction after adjusting, the different grill pans with different depths will not be able to be changed. 
     SUMMARY OF THE INVENTION 
     The present invention provides a grill with adjustable grilling space, whose primary object is to overcome the disadvantages of known grills which cannot adjust the distance between the upper grill pan and the lower grill pan, or of the unsatisfactory adjusting mechanisms of known grills. 
     The present invention adopts the following technical solution. A grill with adjustable grilling space comprises an upper shell, a lower shell, an upper grill pan that is disposed on the bottom surface of the upper shell and a lower grill pan that is disposed on the top surface of the lower shell. The upper shell is connected to the lower shell by hinge mechanisms. The hinge mechanism comprises an upper oscillating rod and a lower oscillating rod. The adjacent ends of the upper oscillating rod and the lower oscillating rod are pivoted to each other, and the removed ends of the upper oscillating rod and the lower oscillating rod are pivoted to the upper shell and lower shell respectively. 
     In one embodiment of the grill with adjustable grilling space, the removed ends of the upper oscillating rod and the lower oscillating rod are connected to the upper shell and the lower shell by an upper shaft seat and a lower shaft seat respectively. The upper shaft seat and the lower shaft seat are fixed to the upper shell and the lower shell respectively. The removed ends of the upper oscillating rod and the lower oscillating rod are pivoted to the upper shaft seat and the lower shaft seat respectively. 
     Both the adjacent ends of said upper oscillating rod and said lower oscillating rod have front locating surfaces and back locating surfaces. When the upper shell and the lower shell are closed, the front locating surfaces of the upper oscillating rod and the lower oscillating rod abut against each other. When the upper shell and the lower shell are open, the back locating surfaces of the upper oscillating rod and the lower oscillating rod abut against each other. 
     Further, a side of the end that is connected to the lower oscillating rod of said upper oscillating rod forms an arc gap; two end surfaces of the arc gap form said front locating surface and back locating surface. The corresponding connecting end of the lower oscillating rod is embedded into the arc gap; the shape of the connecting end is matched with the arc gap. 
     The end that is connected to the upper shaft seat of said upper oscillating rod has a front abutting surface and a back abutting surface, correspondingly the upper shaft seat has a front abutting surface and a back abutting surface that abut against the front abutting surface and the back abutting surface of the upper oscillating rod. When the upper shell and the lower shell are closed or the upper shell and the lower shell are opened to the most, the back abutting surfaces of the upper oscillating rod and the upper shaft seats abut against each other. 
     Further, the end that is connected to the upper shaft seat of said upper oscillating rod has a circular arc groove. Two end surfaces of the circular arc groove form said front abutting surface and back abutting surface. Said upper shaft seat forms a raised part that is used to being inserted into the groove; the shape of the raised part is matched with the groove. 
     The end that is connected to the lower shaft seat of said lower oscillating rod has a front abutting surface and a back abutting surface, correspondingly the lower shaft seat has a front abutting surface and a back abutting surface that abut against the front abutting surface and the back abutting surface of the lower oscillating rod. When the upper shell and the lower shell are closed, or the upper shell and the lower shell are opened to the most, the back abutting surfaces of the lower oscillating rod and the lower shaft seats abut against each other. 
     Further, the end that is connected to the lower shaft seat of said lower oscillating rod has a circular arc groove. Two end surfaces of the circular arc groove form said front abutting surface and back abutting surface. Said lower shaft seat forms a raised part that is used to being inserted into the groove; the shape of the raised part is matched with the groove. 
     Further, the removed ends of the upper oscillating rod and the lower oscillating rod are connected to the upper shaft seat and the lower shaft seat by interference fit; the adjacent ends of the upper oscillating rod and the lower oscillating rod are connected to each other by clearance fit. 
     Further, there are two said hinge mechanisms, which are disposed at the rear ends of left sides and the right sides of the upper shell and the lower shell respectively. 
     Further, there are pre-tension mechanisms between the upper shaft seat and the upper oscillating rod and between the lower shaft seat and the lower oscillating respectively. The pre-tension mechanism comprises a sliding rod that is disposed in the upper shaft seat or the lower shaft seat slidably, a spring that makes the sliding rod protrude towards the upper oscillating rod or the lower oscillating rod and a locating groove that is matched with the protruding part of the sliding rod and is disposed in the upper oscillating rod or the lower oscillating rod. 
     As shown in above-mentioned descriptions and compared with the related art, the present invention has advantages as follows. Firstly, the upper shell is connected to the lower shell by adjustable hinge mechanisms, and the distance between them is adjustable, so it can adjust the grilling space between the upper grill pan and the lower grill pan by changing grill pans with different depths, at the same time it can assure that the upper grill pan is aligned with the lower grill pan in vertical direction. Secondly, in grilling thick food, the distance between the upper grill pan and the lower grill pan can be adjusted to fit the food by adjusting hinge mechanisms that are connected to the upper shell and the lower shell. Thirdly, the hinge mechanisms have simple structure, are not broken easily and have low cost. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of embodiment 1 when a deep grill pan is used. 
         FIG. 2  is a side view of hinge mechanism of embodiment 1 when a deep grill pan is used. 
         FIG. 3  is a side view of embodiment 1 when a flat grill pan is used. 
         FIG. 4  is a side view of hinge mechanism of embodiment 1 when a flat grill pan is used. 
         FIG. 5  is a side view of embodiment 1 when the upper grill pan and the lower grill pan are open. 
         FIG. 6  is a side view of hinge mechanism of embodiment 1 when the upper grill pan and the lower grill pan are open. 
         FIG. 7  is an explosive view of hinge mechanism of embodiment 1. 
         FIG. 8  is a perspective view of hinge mechanism of embodiment 2. 
         FIG. 9  is a cutaway view of the connection of the lower oscillating rod of hinge mechanism and the lower shaft seat of embodiment 2. 
         FIG. 10  is an explosive view of hinge mechanism of embodiment 2. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention will be further described according to the drawings and the embodiments. 
     Embodiment 1 
     Referring to  FIGS. 1 and 3 , a grill with adjustable grilling space, comprises an upper shell  1 , a lower shell  2 , an upper grill pan  3  that is disposed on the bottom surface of the upper shell  1  and a lower grill pan  4  that is disposed on the top surface of the lower shell  2 . The upper shell  1  is connected to the lower shell  2  by hinge mechanisms  5 . The hinge mechanism  5  comprises an upper oscillating rod  51  and a lower oscillating rod  52 . The adjacent ends of the upper oscillating rod  51  and the lower oscillating rod  52  are pivoted to each other, and the removed ends of the upper oscillating rod  51  and the lower oscillating rod  52  are pivoted to the upper shell  1  and lower shell  2  respectively. There are two hinge mechanisms  5 , which are disposed at the rear end of both the left side and the right side of the upper shell  1  and the lower shell  2  respectively.  FIG. 1  and  FIG. 3  are side views, so there is only one hinge mechanism  5  shown. 
     Referring to  FIG. 7 , the removed ends of the upper oscillating rod  51  and the lower oscillating rod  52  are connected to the upper shell  1  and the lower shell  2  by an upper shaft seat  53  and a lower shaft seat  54  respectively. The upper shaft seat  53  and the lower shaft seat  54  are fixed to the left sides and the right sides of the upper shell  1  and the lower shell  2  respectively. The removed ends of the upper oscillating rod  51  and the lower oscillating rod  52  are pivoted to the upper shaft seat  53  and the lower shaft seat  54  respectively, and the pivot shaft are bolts  55  and  57 . The pivot shaft of the adjacent ends of the upper oscillating rod  51  and the lower oscillating rod  52  is bolt  56 . 
     Referring to  FIGS. 2 ,  4 ,  6  and  7 , a side of the end that is connected to the lower oscillating rod  52  of the upper oscillating rod  51  forms an arc gap  512 ; the center of the arc gap  512  is the bolt  56 . Two end surfaces of the arc gap  512  form a front locating surface  5121  and a back locating surface  5122 . The corresponding connecting end of the lower oscillating rod  52  is embedded into the arc gap  512 ; the shape of the connecting end is matched with the arc gap  512 . The lower oscillating rod  52  has a front locating surface  5221  and a back locating surface  5222  that are matched with the front locating surface  5121  and the back locating surface  5122 . Referring to  FIGS. 3 and 4 , when the upper shell  1  and the lower shell  2  are closed, the front locating surface  5121  of the upper oscillating rod  51  and the front locating surface  5221  of the lower oscillating rod  52  abut each other. Referring to  FIGS. 5 and 6 , when the upper shell  1  and the lower shell  2  are open, the back locating surface  5122  of the upper oscillating rod  51  and the back locating surface  5222  of the lower oscillating rod  52  abut each other. Referring to  FIGS. 1 and 2 , when deep grill pan is adopted or when the upper grill pan  3  and the lower grill pan  4  are parallel and there is some distance between them, the front locating surfaces  5121  and  5221  or the back locating surfaces  5122  and  5222  do not abut each other. 
     Referring to  FIGS. 2 ,  4 ,  6  and  7 , the end of the upper oscillating rod  51  that is connected to the upper shaft seat  53  has a circular arc groove  511  with the center being the bolt  55 . Two end surfaces of the circular arc groove  511  form a front abutting surface  5111  and a back abutting surface  5112 . The upper shaft seat  53  forms a raised part  531  that is used to being inserted into the groove  511 ; the shape of the raised part  531  is matched with the groove  511 . The raised part  531  has a front abutting surface  5311  and a back abutting surface  5312  that are matched with the front abutting surface  5111  and the back abutting surface  5112  of the groove  511 . Referring to  FIGS. 3 and 4 , when the upper shell  1  and the lower shell  2  are closed, the back abutting surface  5112  of the upper oscillating rod  51  abuts against the back abutting surface  5312  of the upper shaft seat  53 . Referring to  FIGS. 5 and 6 , when the upper shell  1  and the lower shell  2  are opened to the most, the back abutting surface  5112  of the upper oscillating rod  51  abuts against the back abutting surface  5312  of the upper shaft seat  53  as well. 
     Referring to  FIGS. 2 ,  4 ,  6  and  7 , the end that is connected to the lower shaft seat  54  of the lower oscillating rod  52  has a circular arc groove  521  with the center being the bolt  57 . Two end surfaces of the circular arc groove  521  form a front abutting surface  5211  and a back abutting surface  5212 . The lower shaft seat  54  forms a raised part  541  that is used to being inserted into the groove  521 ; the shape of the raised part  541  is matched with the groove  521 . The raised part  541  has a front abutting surface  5411  and a back abutting surface  5412  that are matched with the front abutting surface  5211  and the back abutting surface  5212 . Referring to  FIG. 4 , when the upper shell  1  and the lower shell  2  are closed, the back abutting surface  5211  of the lower oscillating rod  52  abuts against the back abutting surface  5411  of the lower shaft seat  54 ; when the upper shell  1  and the lower shell  2  are opened to the most, the back abutting surface  5211  of the lower oscillating rod  52  abuts against the back abutting surface  5411  of the lower shaft seat  54  as well. 
     Further, the removed ends of the upper oscillating rod  51  and the lower oscillating rod  52  are connected to the upper shaft seat  53  and the lower shaft seat  54  by interference fit; the adjacent ends of the upper oscillating rod  51  and the lower oscillating rod  52  are connected to each other by clearance fit. So in normal state, the upper oscillating rod  51  cannot turn relatively to the upper shell  1  and the lower oscillating rod  52  cannot turn relatively to the lower shell  2 . Only when grill pans with different depths are changed, relative angles between the upper oscillating rod  51  and the upper shell  1  and the lower oscillating rod  52  and the lower shell can be adjusted. 
     Embodiment 2 
     Referring to  FIGS. 8 and 10 , the embodiment has a similar structure to embodiment 1. The difference= is that there are pre-tension mechanisms between the upper shaft seat  53  and the upper oscillating rod  51  and between the lower shaft seat  54  and the lower oscillating rod  52 . 
     The pre-tension mechanism between the lower shaft seat  54  and the lower oscillating rod  52  is illustrated below as an example. Referring to  FIGS. 8 and 10 , the pre-tension mechanism comprises a sliding rod  543  disposed slidably in the lower shaft seat  54 , a spring  544  that makes the sliding rod  543  protrude towards the lower oscillating rod  52  and a locating groove  5430  that is matched with the protruding part  5431  of the sliding rod  543  and is disposed in the lower oscillating rod  52 . 
     When there is some distance between the upper grill pan  3  and the lower grill pan  4 , just as shown in  FIG. 1 , the protruding part  5431  of the sliding rod  543  is matched with the locating groove  5430  of the lower oscillating rod  52  to ensure that the lower oscillating rod  52  is located relatively to the lower shaft seat  54 . The lower shaft seat  54  has an integrative U-shaped piece  542 . The sliding rod  543  gets through and is disposed slidably between the two side walls of the U-shaped piece  542 . The spring covers the sliding rod  543 . 
     Referring to  FIGS. 8 and 10 , the pre-tension mechanism between the upper shaft seat  53  and the upper oscillating rod  51  has the same structure with the pre-tension mechanism between the lower shaft seat  54  and the lower oscillating rod  52 . Corresponding parts are the sliding rod  533 , the protruding part  5331 , the spring  534 , the U-shaped piece  532  and the locating groove  5330 . 
     The foregoing description of the exemplary embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teachings. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.