Abstract:
A foldable electric fan, comprising: a fan head, a support tube and a base, a turnover mechanism for turning the fan head up or down is provided between the top of the support tube and the fan head, is disclosed. Further, the base is foldable, and the electric fan can be arranged into a desk fan or a floor fan by turning the fan head up or down, and can be used for several different purposes in more broad fields. The fan head and the base of the electric fan can be folded-up, which reduces the space it occupies and cuts down the cost of package and transportation. Moreover, the foldable electric fan effectively reduces the inconvenience of traditional electric fans which need to be detached into several parts during package and transportation, and then assembled together for use.

Description:
FIELD OF TECHNOLOGY 
     The following relates to electric fans, and more particularly relates to a foldable electric fan. 
     BACKGROUND 
     A regular floor fan, as shown in  FIG. 1 , generally comprises a fan head  1 ′, a support shank  2 ′ and a base  3 ′, which sequentially connected with each other. The support shank  2 ′ is retractable, so the upright height of the fan head  1 ′ is adjustable by raising the support shank  2 ′ up or drawing it down. However, the adjustable range of height of the fan head  1 ′ is restricted, because the retractable length of the support shank  2 ′ is limited, such an electric fan can be arranged into a floor fan only, and can not be arranged into a desk fan. Moreover, the fan head  1 ′, the support shank  2 ′ and the base  3 ′ need to be detached during package and transportation, and the user has to reassemble them together before using. The process of detachment is time-consuming, and the operation is complicated. A risk of losing some tiny parts may also exist. Further, influenced by the size of the base which is usually a regular disc-like base and the length of the support shank, the electric fan after detachment also occupies a large space even if it can be detached into several parts and packed up separately. Thus, the cost of package and transportation is greatly increased. 
     SUMMARY 
     In view of the problems and drawbacks, an object of the present invention is to provide a foldable electric fan which can be arranged into a floor fan or a desk fan by turning the fan head up or down. Moreover, the fan head and the base of this fan can be folded-up, which greatly reduce the space it occupies and cut down the cost of package and transportation. Moreover, the present invention effectively avoid the inconvenience of traditional electric fans which need to be detached into several parts during package and transportation, and then the parts need to be assembled together for use. It also reduces the process of packing, saves time and energy, with high practicability. 
     To achieve the above object, the present invention employs the following technical solution: 
     A foldable electric fan, comprising a fan head, a support tube and a base, a turnover mechanism is provided between the top of the support tube and the fan head for turning the fan head up or down. 
     The support tube comprises two erect tubes and two height-adjusting tubes which engaging with the two erect tubes respectively. The turnover mechanism is connected between the top of the two height-adjusting tubes and the fan head. 
     The turnover mechanism according to the invention comprises a connecting block connected on the top of the two height-adjusting tubes, and a fan head joining tube connected on the middle part of the top of the connecting block. Two axes are respectively provided on both sides of the connecting block, each axis goes through a hole on the height-adjusting tube and hinge connects with a nut. 
     As an improvement of the present invention, an automatic position-limit and locking mechanism is arranged on the top of the connecting block and the height-adjusting tube to limit and lock the turnover mechanism for locking the fan head tighter when the electric fan stands upright. As a further improvement of the present invention, the automatic position-limit and locking mechanism is a spring bolt provided on the connecting block, comprising a seat fixed on said connecting block, a rod through a hole on the seat, a compression spring surrounding the rod, and a locating hole on the top of the height-adjusting tube for mating with the rod. 
     Moreover, the automatic position-limit and locking mechanism may be a pawl ratchet assembly installed between the end of the connecting block and the height-adjusting tube. A pivot on the end of the connecting block sequentially passes through a center hole of the ratchet and a mounting hole on the top of the height-adjusting tube, and then connects with a nut. The pawl engaging with the ratchet is configured between the end of the connecting block and the ratchet. A rotatable handle is fixed joint on the outside surface of the pawl, and a V-shape spring providing the elastic resilience of the pawl is configured between the connecting block and the pawl. 
     The base according to the present invention has three types as follows: 
     Firstly, the base comprises a stationary base paralleled with the fan head, a vertical moveable base which can be turned upwardly, and a horizontal moveable base which can be horizontally folded toward a side of the stationary base. The vertical moveable base is articulated with the middle part of the stationary base by a horizontal first door hinge assembly. Further, the horizontal moveable base is also articulated with the stationary base by a vertical second door hinge assembly. Safety bolts are provided on the corresponding place of the stationary base to fasten the vertical moveable base and the horizontal moveable base. The vertical moveable base can be turned upwards and the horizontal moveable base can be folded toward a side of the stationary base while storing the base, then the whole base can be folded-up, which greatly reduces the space it occupied. 
     Secondly, the base comprises a stationary base paralleled with the fan head, and a rotatable base under the stationary base. The rotatable base can be folded to the stationary base. And the rotatable base is detachable joint with the stationary base by a lock nut, a fastening bolt and a lock screw. The lock nut, the lock screw and the fastening bolt can be loosen, and the rotatable base can be turned and engaged with the lower part of the stationary base while storing the base, this greatly reduces the space it occupied. 
     Thirdly, the base comprises a stationary base paralleled with the fan head, and a rotatable base under the stationary base. The rotatable base can be folded towards the stationary base. And the rotatable base is detachable joint with the stationary base by a fastening bolt. The fastening bolt can be loosen and the rotatable base can be turned and engaged with the lower part of the stationary base while storing the base, this greatly reduces the space it occupied. 
     The present invention has the following advantageous effects as compared with the prior art: 
     (1) The fan head can be turned up or down by the turnover mechanism, so that the electric fan can be arranged into a desk fan or a floor fan , this means that the electric fan can be used for several different purposes in more broad fields; 
     (2) The fan head can be turned down, which helps to fold-up and store and greatly reduces the space in the height direction it occupied. Furthermore, the base of the electric fan can be folded-up for storing, which efficiently reduces the space the base taken. Thus the electric fan is overall structurally compact, which reducing the space it occupied and cutting down the cost of package and transportation; 
     (3) The electric fan according to the invention can be packed and transported without detaching and reassembling, which greatly reduces the inconvenience during detachment and reassembly, saves time and energy, with high practicability. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       To make the present invention more clearly comprehensible, preferred embodiments of the present invention will be described with reference to the drawings. 
         FIG. 1  is a schematic view of a conventional floor fan; 
         FIG. 2  is a schematic view of a floor fan according to the present invention. 
         FIG. 3  is a schematic view of a desk fan according to the present invention. 
         FIG. 4  is a first schematic view of a folded electric fan according to Embodiment 1 of the present invention; 
         FIG. 5  is a second schematic view of an electric fan with the horizontal moveable base opened according to Embodiment 1 of the present invention; 
         FIG. 6  is a third schematic view of an electric fan with the vertical moveable base opened according to Embodiment 1 of the present invention; 
         FIG. 7  is a fourth schematic view of an electric fan with its fan head turned according to Embodiment 1 of the present invention; 
         FIG. 8  is a fifth schematic view of an electric fan being arranged into a floor fan according to Embodiment 1 of the present invention; 
         FIG. 9  is a sixth schematic view of an electric fan being adjusting its height according to Embodiment 1 of the present invention; 
         FIG. 10  is an exploded view of an electric fan according to Embodiment 1 of the present invention; 
         FIG. 11  is a first stereoscopic view of the back of an electric fan according to Embodiment 1 of the present invention; 
         FIG. 12  is an enlarged view of part A of  FIG. 11 ; 
         FIG. 13  is a second stereoscopic view of the back of an electric fan according to Embodiment 1 of the present invention; 
         FIG. 14  is an enlarged view of part B of  FIG. 13 ; 
         FIG. 15  is a first stereoscopic view of the front of an electric fan according to Embodiment 1 of the present invention; 
         FIG. 16  is an enlarged view of part C of  FIG. 15 ; 
         FIG. 17  is a third stereoscopic view of the back of an electric fan according to Embodiment 1 of the present invention; 
         FIG. 18  is an enlarged view of part D of  FIG. 17 ; 
         FIG. 19  is a schematic view of the internal structure of the safety bolt; 
         FIG. 20  is an exploded view of the safety bolt; 
         FIG. 21  is a schematic view of the turnover mechanism according to Embodiment 1 of the present invention; 
         FIG. 22  is a schematic view of the turnover mechanism according to Embodiment 2 of the present invention; 
         FIG. 23  is a first schematic view of the pawl ratchet assembly according to Embodiment 2 of the present invention, showing the engagement of the ratchet and the pawl when the fan is folded; 
         FIG. 24  is a second schematic view of the pawl ratchet assembly according to Embodiment 2 of the present invention, showing the engagement of the ratchet and the pawl when the fan is turning; 
         FIG. 25  is a third schematic view of the pawl ratchet assembly according to Embodiment 2 of the present invention, showing the engagement of the ratchet and the pawl when the fan is a floor fan; 
         FIG. 26  is an exploded view of the base according to Embodiment 3 of the present invention; 
         FIG. 27  is an assembly view of the base according to Embodiment 3 of the present invention; 
         FIG. 28  is a schematic view of the base in use according to Embodiment 3 of the present invention; 
         FIG. 29  is an exploded view of the base according to Embodiment 4 of the present invention; 
         FIG. 30  is an assembly view of the base according to Embodiment 4 of the present invention; 
         FIG. 31  is a schematic view of the base in use according to Embodiment 4 of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiment 1 
     As shown in  FIGS. 2-17 , a foldable electric fan according to the present invention comprises a fan head  1 , a support tube  2  and a base  3 . A turnover mechanism  4  for turning the fan head  1  up or down is provided between the top of the support tube  2  and the fan head  1 . Further, the base  3  according to the present invention is foldable. 
     The support tube  2  comprises two erect tubes  21  and two height-adjusting tubes  22  which engage with the two erect tubes respectively. The turnover mechanism  4  is connected between the top of the two height-adjusting tubes  22  and the fan head  1 . 
     As shown in  FIGS. 6 ,  8 - 11 ,  21 , the turnover mechanism  4  comprises a connecting block  41  on the top of the two height-adjusting tubes  22 , and a fan head joining tube  42  connected on the middle part of the top of the connecting block  41 . An axis  411  is provided on both sides of the connecting block  41 , passing through a rubber pad  43  and a hole  222  on the height-adjusting tube  22  sequentially, and then hinge connected by a nut  44 . 
     Furthermore, an automatic position-limit and locking mechanism is provided on the top of the connecting block  41  and the height-adjusting tube  22  to limit and lock the turnover mechanism  4  for locking the fan head  4  tighter when the electric fan stands upright. The automatic position-limit and locking mechanism is a spring bolt  5  arranged on the connecting block  41 , comprising a seat  51  fixed on the connecting block  41 , a rod  52  through a hole in the seat  51 , a compression spring  53  surrounding the rod  52 , and a locating hole  221  on the top of the height-adjusting tube  22  for mating with the rod  52 . 
     When the fan head  1  needs to be turned downwardly, pulling the rod  52  out and disengaging it from the locating hole  221 , then the turnover mechanism  4  can be unlocked, and the fan head  1  can be turned up or down freely, as shown in  FIGS. 6-9 . When the fan head  1  of the electric fan needs to be arranged from a folded fan into a floor fan, the turnover mechanism  4  is turned so as to turn the fan head  1  upwardly until it stands upright, here the rod  52  can be moved back into the locating hole  221  of the height-adjusting tube  22  by the compression spring  53 , and then the turnover mechanism  4  can be locked, preventing the hidden security troubles caused by not tightening or locking the nuts of the turnover mechanism  4 . 
     According to this embodiment, as shown in  FIGS. 7-17 , the base  3  comprises a stationary base  31  paralleled with the fan head  1 , a vertical moveable base  32  which can be turned upwardly, and a horizontal moveable base  33  which can be horizontally folded toward a side of the stationary base  31 . The vertical moveable base  32  is articulated with the middle part of the stationary base  31  by a horizontal first door hinge assembly  34 . The horizontal moveable base  33  is also articulated with the stationary base  31  by a vertical second door hinge assembly  35 . Thus, the vertical moveable base  32  may be turned upwardly around the first door hinge assembly  34  which acts as a pivot, and the horizontal moveable base  33  may be turned towards the side of the stationary base  31  around the second door hinge assembly  35  which acts as a pivot. This helps to fold and store the base and reduces the space it occupied. 
     As shown in  FIGS. 10 ,  15 - 20 , two first safety bolt assembly  6  are provided on the corresponding place of the stationary base  31  for locking and limiting the vertical moveable base  32 , and a second safety bolt assembly  7  is provided for locking and limiting the horizontal moveable base  33 , wherein the first safety bolt assembly  6  is fixed on a place of the stationary base  31  which corresponding to the vertical moveable base  32 , and the second safety bolt assembly  7  is fixed on a place of the stationary base  31  which corresponding to the horizontal moveable base  33 . The structure of the first safety bolt assembly  6 , the second safety bolt assembly  7  and the spring bolt  5  are similar. As shown in  FIGS. 19-20 , both of them comprises a seat  61 / 71 , a rod  62 / 72  through a hole in the seat  61 / 71 , a compression spring  63 / 73  surrounding the rod  62 / 72 . A first oriented groove  321  and a first bore  322  copulating with the rod  62  are provided on the bottom of the vertical moveable base  32 . The first oriented groove  321  is convenient for inserting the rod  62  into the first bore  322 . A second oriented groove  331  and a second bore  332  copulating with the rod  72  are provided on the bottom of the horizontal moveable base  33 . The second oriented groove  331  is convenient for inserting the rod  72  into the second bore  332 . 
     The locking and limiting principle of two first safety bolt assembly  6  and the second safety bolt assembly  7  are completely the same with the spring bolt  5  of the turnover mechanism  4 , which may not be described herein. 
     Furthermore, according to the present invention, two wheels  9  are provided in the front of the bottom of the base  3 , so the electric fan is easy to move whenever it needs to. 
     Embodiment 2 
     The structure according to this embodiment and Embodiment 1 are almost the same, but the structure of the automatic position-limit and locking mechanism of the turnover mechanism  4  in this embodiment is different. As shown in  FIG. 22 , the automatic position-limit and locking mechanism is a pawl ratchet assembly  8  installed between the end of the connecting block  41  and the height-adjusting tube  22 . A pivot  411  on the end of the connecting block  41  passes through a center hole of the ratchet  81  and a mounting hole on the top of the height-adjusting tube  22  sequentially, and then connected with a nut  44 . The pawl  82  engaging with the ratchet  81  is articulated with the inside of the top of the height-adjusting tube  22 . A rotatable handle  83  is fixed joint on the outside of the pawl  82 . As shown in  FIGS. 23-25 , a V-shape spring  84  is tightened on the inside of the top of the height-adjusting tube  22  for providing the elastic resilience of the pawl  82 . 
     As shown in  FIG. 23 , when the fan head  1  is folded-up, the pawl  82  can be engaged and limited by the ratchet  81 , thus the fan head  1  can be turned upwardly only. As shown in  FIG. 24 , when the fan head  1  is turned on betweenness, the fan head  1  can not be turned downwardly and can be fixed on any arbitrary angle because the ratchet  81  is fastened by the pawl  82 . As shown in  FIG. 25 , when the fan head  1  is being arranged into a floor fan, the ratchet  81  can be turned and locked by the automatic position-limit and locking mechanism, the pawl  82  can be locked on the present state for a better effect of limiting and locking. Moreover, when the fan head  1  need to be folded-up, the rotatable handle  83  may be rotated, then the pawl  82  is disengaged with the ratchet  81 , and the fan head  1  can be turned and arranged into a folded fan. 
     Embodiment 3 
     The difference between this embodiment and Embodiment 1 is shown in  FIG. 26 , the base  3  comprises a stationary base  31  paralleled with the fan head  1 , and a rotatable base  36  under the stationary base  31 . The rotatable base  36  can be engaged with the bottom of the stationary base  31 . The rotatable base  36  is detachable joint with the stationary base  31  by a lock nut  37 , a fastening bolt  38  and a lock screw  39 . 
     As shown in  FIGS. 26-27 , when the electric fan needs to be folded, the lock nut  37 , the lock screw  39  can be loosen, and the fastening bolt  38  can be taken off, and the rotatable base  36  can be rotated and engaged with the lower part of the stationary base  31 . As shown in  FIG. 28 , when the electric fan needs to be arranged into a floor fan or a desk fan, the rotatable base  36  and the stationary base  31  cross and tighten with each other, insuring the stability of the electric fan. 
     Embodiment 4 
     The structure according to this embodiment and Embodiment 3 are almost the same. The difference is that only a fastening bolt  38  is provided on the center of the stationary base  31  and the rotatable base  36  for engagement in this embodiment. 
     As shown in  FIGS. 29-30 , when the electric fan needs to be folded, the fastening bolt  38  can be loosen, and the rotatable base  36  can be engaged with the lower part of the stationary base  31 . As shown in  FIG. 31 , when the electric fan needs to be arranged into a floor fan or a desk fan, the rotatable base  36  and the stationary base  31  cross and tighten with each other, insuring the stability of the electric fan. 
     Furthermore, the height-adjusting tube  22  according to the present invention can be demounted, i.e. the turnover mechanism  4  is directly arranged on the erect tubes  21 . 
     The present invention is not limited to the above embodiments. If various modification or variations to the present invention do not depart from the spirit and scope of the present invention, the present invention also intends to contain the various modifications and variations if they fall within the scope of claims of the present invention and equivalent technologies.