Abstract:
A stepwise powerful suction device includes suction holders, suction elements, resilient elements, a support frame, and rotary knobs. The support frame and the three suction holders are integrally formed together. A portion of the support frame forms a handle. Each suction element forms an upright post extending through the respective resilient element and suction holder. Each suction holder forms a multi-step stepwise recess, and each rotary knob has a handgrip that forms a multi-step stepwise projection overlappingly engaging the multi-step stepwise recess and including a safety button, a spacer ring, and a bolt extending through the handgrip of the rotary knob to engage an inner-threaded hole defined in the respective suction element. Each suction holder forms a stop, and the handgrip of the respective rotary knob forms a counterpart raised portion. When the handgrip of the rotary knob is rotated from a released position to first, second, and third engaging position, respective suction forces, which are sequentially of small, intermediate, and large magnitudes, are induced to effect various sucking operations on plates of different materials and thicknesses.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a suction device, and in particular to a stepwise powerful suction device that is controlled to selectively generate suction forces of different magnitudes for different applications in holding panels or boards of different thicknesses. 
         [0003]    2. The Related Arts 
         [0004]      FIGS. 1 and 2  of the attached drawings illustrate a conventional suction device, which comprises two suction holders  11 , two suction elements  12 , two springs  13 , two switch levers  14  and a support frame  15 . A portion of the support frame  15  forms a handle. Each suction holder  11  forms a central hole  112  and has a top forming a platform  111 . The suction element  12  is made of a deformable material and forms an upright post  122 . The upright post  122  forms at an upper end section thereof a pin hole  123  that receives therein a pin  124 . Each switch lever  14  has an end forming a pivoting portion  141  in which a pivot hole  143  is defined. The pivoting portion  141  also has a camming edge  142 . The spring  13  encompasses the upright post  122  of the suction element  12 . The upright post  122  of the suction element  12  extends through the hole  112  of the suction holder to position the suction element  12  under the bottom of the suction holder  11  with the spring  13  normally biasing the suction element  12  away from the bottom of the suction holder  11 . The upright post  122  is set to have the pin hole  123  thereof aligned with pivot hole  143  of the switch lever  14  to allow the pin  124  to extend through both, whereby the switch lever  14  is rotatable with respect to the suction holder  11 . In operation, the rotatable and thus position-changeable switch lever  14  is arranged to have the camming edge  142  thereof engaging the platform  111  of the suction holder  11  so that rotation of the switch lever  14  causes, via the pivotal joint thereof with the upright post  122 , the suction element  12  to be forced upward. With the suction element  12  positioned on a smooth surface of for example a glass panel or a board or the likes, vacuum is induced inside the suction element  12  thereby generating a suction force to hold the glass panel or the board to the suction element  12 . 
         [0005]    The conventional suction device has disadvantages. For example, the suction force so induced by the suction element is not adjustable so that it only provides a constant magnitude. This works for holding thick glass panels or thick boards that are capable to endure a large force without breaking or fracture, but when applied to a glass panel or a board of a small thickness, which is capable to sustain a large force, the fixed magnitude suction force generated by the conventional suction device may unexpectedly break the glass panel or board, leading to property loss or even damage to people. 
         [0006]    In view of the above discussed drawbacks, it is desired to have a suction device that overcomes the above problems. 
       SUMMARY OF THE INVENTION 
       [0007]    Thus, the present invention aims to solve the problem that the conventional suction device provides only a fixed-magnitude suction force by switching a lever to lift an upright post of a suction element and that the suction force is not adjustable and is thus only applicable to panels or boards of sufficient thicknesses and not applicable to panels or boards of small thicknesses that may be broken by the fixed magnitude of the suction force. 
         [0008]    To solve such problems and drawbacks, the present invention provides a stepwise powerful suction device comprising a plurality of suction holders, a plurality of suction elements, a plurality of resilient elements, a support frame, and a plurality of rotary knobs. The support frame and the rotary knobs are integrally formed together. A portion of the support frame forms a handle. Each suction element has an upright post extending through the corresponding resilient element and the corresponding suction holder. Each suction holder forms a multi-step stepwise recess and the corresponding rotary knob has a handgrip forming a multi-step stepwise projection mating the multi-step stepwise recess in a stacked manner. Safety locking means is provided between the multi-step stepwise recess and the multi-step stepwise projection. A spacer ring and a bolt are received in a bore of the handgrip to secure the upright post of the suction element to the handgrip. The suction holder forms a stop on an outside surface thereof and the handgrip forms a corresponding raised portion. When the handgrip is switched by rotation from a neutral position to a first engaging position, the multi-step stepwise projection is caused to move respect to the multi-step stepwise recess to have steps of multi-step stepwise projection engaging different steps of the multi-step stepwise recess thereby moving the suction element upward by a first distance that induce a first magnitude of suction force. Further rotation of the handgrip toward subsequent engaging positions causes the multi-step stepwise projection to set at different steps of the multi-step stepwise recess and lifting the suction element by different distances that induces different magnitudes of the suction force. This allows the suction device of the present invention to be applicable to panels or boards of different size without applying excessive suction force thereto. 
         [0009]    The effectiveness of the present invention is that, compared to the conventional suction device that generates only a fixed magnitude suction force that is only applicable to panels or boards of sufficient thicknesses and may break panels or boards of small thicknesses, the stepwise suction device of the present invention is controllable to provide a suction force of various magnitudes for applications to panels or boards of a wide range of thickness without applying an excessive force to undesirably cause breaking of the panel or board held thereby. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The present invention will be apparent to those skilled in the art by reading the following description of a preferred embodiment thereof, with reference to the attached drawings, wherein: 
           [0011]      FIG. 1  is a perspective view of a conventional two-suction-element suction device; 
           [0012]      FIG. 2  is a cross-sectional view of the conventional suction device illustrating the operation of the suction element thereof; 
           [0013]      FIG. 3  is an exploded view of a stepwise powerful suction device constructed in accordance with a preferred embodiment of the present invention; 
           [0014]      FIG. 4  is a perspective view illustrating an arrangement of a multi-step stepwise recess and a multi-step stepwise projection of the stepwise powerful suction device of the present invention; 
           [0015]      FIG. 4A  is view illustrating spatial relationship between the multi-step stepwise recess and multi-step stepwise projection; 
           [0016]      FIG. 5  is a cross-sectional view of the stepwise powerful suction device of the present invention; 
           [0017]      FIG. 6  is another cross-sectional view of the stepwise powerful suction device of the present invention; 
           [0018]      FIG. 7  is a top view of the stepwise powerful suction device of the present invention that comprises three suction elements; 
           [0019]      FIG. 8  is a perspective view of the stepwise powerful suction device of the present invention that comprises three suction elements; 
           [0020]      FIG. 9  is an exploded view of a stepwise powerful suction device constructed in accordance with another embodiment of the present invention that comprises two suction elements; 
           [0021]      FIG. 10  is a top view of the stepwise powerful suction device of the present invention that comprises two suction elements; 
           [0022]      FIG. 11  is a perspective view of the stepwise powerful suction device of the present invention that comprises two suction elements; and 
           [0023]      FIG. 12  is a perspective view illustrating a stepwise powerful suction device constructed in accordance with a further embodiment of the present invention that comprises a single suction element. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0024]    The present invention provides a stepwise powerful suction device, which is particularly illustrated in  FIGS. 3 ,  4 , and  4 A, which are respectively an exploded view of the stepwise powerful suction device in accordance with a preferred embodiment of the present invention, a perspective view illustrating an arrangement of a multi-step stepwise recess and a multi-step stepwise projection of the stepwise powerful suction device of the present invention, and a view illustrating spatial relationship between the multi-step stepwise recess and projection. The suction device in accordance with the first embodiment of the present invention comprises three suction holders  21 , three suction elements  22 , three resilient elements  23 , a support frame  24 , and three rotary knobs  30 . The resilient elements  23  are compression springs. The support frame  24  and the three suction holders  21  are fixed together, preferably by being integrally molded or otherwise integrally formed together. A portion of the support frame  24  forms a handle. Each suction holder  21  forms a central bore  211  and a multi-step stepwise recess  40 , preferably arranged in a concentric manner. The central bore  211  has an inside surface in which slots  212 , preferably opposite to each other, are defined for slidably receiving guide pegs  222  (which will be described hereinafter) therein. The multi-step stepwise recess  40  is comprised of two sets of a first step  41 , which is of a greatest depth, a second step  42 , which is of a second greatest depth, a third step  43 , which is of a second shallowest depth, and a fourth step  44 , which is of a shallowest depth. The steps  41 ,  42 ,  43 ,  44  of the two sets are circumferentially arranged, preferably equally spaced, and respectively correspond at least eight sequentially arranged position marks, respectively denoted as 0, 1, 2, 3, 0, 1, 2, 3, which are formed on an outside surface of the corresponding suction holder  21  in an angularly and equally spaced manner. A stop  45  is also formed on the outside surface of the suction holder  21  at a location adjacent to one of the two fourth steps  44  to correspond to a raised portion  311  formed on a handgrip  31  of the corresponding rotary knob  30 , whereby when the handgrip  31  is angularly moved to an extreme position, the raised portion  311  engages the stop  45  to prevent further rotation or angular movement of the handgrip  31 . 
         [0025]    Each suction element  22  comprises an upright post  221  from which the guide pegs  222  extend sideways to make the suction element  22  vertically movable, but not angularly movable or rotatable. A top end of the upright post  221  forms an inner-threaded hole  223 . Each rotary knob  30  comprises a handgrip  31 , a spacer ring  32 , a bolt  33 , and a cap  34 . The handgrip  31  has an under surface that forms a multi-step stepwise projection  50  corresponding in geometry and size to the multi-step stepwise recess  40  of the corresponding suction holder  21 . The multi-step stepwise projection  50  is comprised of two sets of a fourth step  51 , which is of a greatest height, a third step  52 , which is of a second greatest height, a second step  53 , which is of a second lowest height, and a first step  54 , which is of a lowest height. The steps  51 ,  52 ,  53 ,  54  of the two sets are sequentially arranged and preferably equally spaced and respectively correspond to the eight sequentially arranged position marks of the corresponding suction holder  21  in the sequence of 3, 2, 1, 0, 3, 2, 1, 0. 
         [0026]    To assemble, the upright post  221  of each suction element  22  extends through the corresponding resilient element  23  and the central bore  211  of the corresponding suction holder  21  with the guide pegs  222  slidably received in the slots  212  of the suction holder  21 . The multi-step stepwise projection  50  of each handgrip  31  is set in and overlapping stacked on the multi-step stepwise recess  40  of the corresponding suction holder  21 . Each handgrip  31  forms a stepped bore  312  (see  FIG. 6 ) that receives the corresponding spacer ring  32  therein. The upright post  221  of the suction element  22  is fit through the spacer ring  32  and the bolt  33  extends through the spacer ring  32  to engage the inner-threaded hole  223  of the suction element  22 . Then, the stepped bore  312  of the handgrip  31  is closed by the cap  34 . This completes the assembling of the stepwise powerful suction device of the present invention. 
         [0027]    Safety locking means is provided between the multi-step stepwise recess  40  and the multi-step stepwise projection  50 , comprising a groove  401  formed in each of the steps  41 - 44  of the multi-step stepwise recess  40  and a corresponding rib  501  formed on each of the steps  51 - 54  of the multi-step stepwise projection  50 . When the multi-step stepwise projection  50  undergoes an angular movement with respect to the multi-step stepwise recess  40  to reach each one of a plurality predetermined engaging positions that is defined by inter-engagement between the steps  41 - 44  and the steps  51 - 54 , the rib  501  of the step  51 - 54  of the multi-step stepwise projection  50  and the groove  401  of the inter-engaging step  41 - 44  of the multi-step stepwise recess  40  engage each other to lock the step  51 - 54  of the multi-step stepwise projection  50  with respect to the steps  41 - 44  of the multi-step stepwise recess  40 . This prevents the handgrip  31  that forms the multi-step stepwise projection  50  from unexpectedly disengaging from and moving away from the designated engaging position. 
         [0028]    It is apparent that the multi-step stepwise recess  40  of the suction holder  21  can be comprised of less or more steps, such as three angularly and equally spaced steps that are sequentially of a greatest depth, a second greatest depth, and a shallowest depth, or alternatively six angularly and equally spaced steps, which are sequentially of a greatest depth, a second greatest depth, a shallowest depth, the greatest depth, the second greatest depth, and the shallowest depth. 
         [0029]    Similarly, the multi-step stepwise projection  50  formed on the under surface of the handgrip  31  corresponding to the multi-step stepwise recess  40  of the suction holder  21  can alternatively be comprised of at least three angularly and equally spaced steps that are sequentially of a greatest height, a second greatest height, and a lowest height, or further alternatively at least six angularly and equally spaced steps, which are sequentially of a greatest height, a second greatest height, a lowest height, the greatest height, the second greatest height, and the lowest height. 
         [0030]    Referring to  FIGS. 5 and 6 , to operate, the handgrip  31  is rotated to a desired engaging position, depending upon whether the glass panel or the board  60  that is to be held is a thick panel or board, or a thin panel or board. When the handgrip  31  is rotated in such way that the fourth step  51  (see  FIG. 4 ) of the multi-step stepwise projection  50  thereof is stacked on the third step  43  of the multi-step stepwise recess  40  of the corresponding suction holder  21 , a suction force of a second greatest magnitude is generated, which can be used to suck at and hold a glass panel  60  of a second greatest thickness. In the same way, to suck at and hold a glass panel or board of a different thickness, the handgrip  31  is rotated to an engaging position corresponding to a desired mark of the suction holder  21 . During the rotation of the handgrip  31 , due to the separation realized through the spacer ring  32 , the rotating power is not transmitted to the bolt  33 . When the handgrip  31  undergoes rotation, the multi-step stepwise projection  50  thereof is caused to climb upward the multi-step stepwise recess  40  (see  FIG. 4 ), which lifts the upright post  221  of the suction element  22  upwards. The upward movement of the upright post  221  induces a vacuum suction force inside the suction element  22  that sucks at and holds the glass panel or board  60 . 
         [0031]      FIGS. 7 and 8  show a top view and a perspective view of the three-suction-element stepwise powerful suction device discussed above. The suction device comprises a combination of three suction elements that is supported by the suction holders  21  that are integrally formed with the support frame  24  and that are operated by rotary handgrips  31 . 
         [0032]    Referring to  FIGS. 9-11 , which are an exploded view, a top plan view, and a perspective view of a stepwise powerful suction device constructed in accordance with another embodiment of the present invention, the stepwise powerful suction device of said another embodiment of the present invention comprises a combination of two suction elements that is respectively supported by two suction holders  21  that are integrally formed with a support frame  24 . Each suction holder  21  forms a multi-step stepwise recess  40 , a central bore  211 , and one or more slots  212  that slidably receive guide pegs  222  of an upright post  221  of a corresponding one of the two suction elements  22 . The suction holder  21  forms, on an outside surface thereof, a stop  45  at a location adjacent to the multi-step stepwise recess  40 . Each of the suction elements  22  comprises the upright post  221  and at least one guide peg  222 . The upright post  221  has a top end forming an inner-threaded hole  223 . The upright post  221  extends through a resilient element  23  and the central bore  211  of the corresponding suction holder  21  with the guide peg(s)  222  respectively received in the slot(s)  212 . A rotary knob  30  is associated with each suction holder  21  and the associated suction element  22 . The rotary knob  30  comprises a handgrip  31  that forms a multi-step stepwise projection  50  to stackingly mate the multi-step stepwise recess  40  of the corresponding suction holder  21 . The handgrip  31  forms a stepped bore  312  to receive a spacer ring  32 . A bolt  33  extends through the spacer ring  32  and threadingly engages the inner-threaded hole  223  of the upright post  221 . A cap  34  then closes the stepped bore  312  of the handgrip  31 . As such, a stepwise powerful suction device is formed. When the rotary knob  30  is rotated, the multi-step stepwise projection  50  climbs upward the multi-step stepwise recess  40  to lift the upright post  221  upward, which causes the suction element  22  to generate vacuum suction force. The higher the climbing is, the greater the suction will be, this being applicable to sucking at and holding a glass panel or a board of a large thickness; and the lower the climbing is, the smaller the suction will be, this being applicable to sucking at and holing a glass panel or a board of a small thickness. No climbing indicates no suction force is generated. 
         [0033]    Referring to  FIG. 12 , which shows a perspective view of a stepwise powerful suction device constructed in accordance with a further embodiment of the present invention, the suction device of said further embodiment of the present invention comprises a single suction element that is supported by a suction holder  21  integrally formed with a support frame  240 . The suction holder  21  is provided with a handgrip  31  that operates to change the suction force induced by the suction element in substantially the same way as what described above with reference to the previous embodiments. 
         [0034]    The advantages of the stepwise powerful suction device of the present invention are: 
         [0035]    (1) A novel structure for realizing stepwise powerful suction is provided, which may employ a suction element assembly comprising a single suction element, two suction elements, three suction elements, or more than three suction elements to provide a powerful suction force and which selectively generate a suction force of a proper magnitude in accordance with the thickness of a panel or board to be held, so that the stepwise powerful suction device is applicable to panels or boards of various thicknesses and the suction force generated thereby is of a proper magnitude that does not cause breaking or fracture of the panel or board. The operation is thus safe and risk of breaking glass panels or boards can be reduced. 
         [0036]    (2) A unique feature of the stepwise powerful suction device of the present invention is to replace the conventional switching type suction generating operation with mated multi-step stepwise structures, which are operated through rotation of a rotary handgrip, wherein, in particular, the handgrip forms a multi-step stepwise projection that stackingly mate a multi-step stepwise recess formed in a suction holder so that the rotation of the handgrip causes the multi-step stepwise projection to climb upward the multi-step stepwise recess in a multiple step manner of which each step represents an individual magnitude of the suction force so generated. Thus, the stepwise powerful suction device is applicable to a glass panel or a board of a large thickness by generating a large suction force and is also applicable to a glass panel or a board of a small thickness by generating a small suction force. The stepwise powerful suction device is thus applicable to panels or boards of various thicknesses. 
         [0037]    Although the present invention has been described with reference to the preferred embodiments thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.