Patent Publication Number: US-2022219611-A1

Title: Multifunction Ladder Structure

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to a ladder structure, and more particularly, to a multifunction ladder structure that can either be used as a tire ladder or as an A-shaped ladder and can be applied to a variety of types or models of cars. 
     2. Description of Related Art 
     As cars are being in wide use nowadays for leisure activities or in recreations, MPVs, SUVs or CUVs are gaining more and more popular for people to acquire a car. With common characteristics and in nature, those vehicles are generally higher and are thus usually inconvenient when putting things on or fetching things from the car top, or just attempting to clean the car top. Sometimes, it may even unconsciously cause some unpredictable dangers. A ladder, or more specifically, a tire ladder for car use then often provides a general and popular solution. 
     While the tire ladders or ladders used on cars nowadays are mostly ladders of limited function that can either be used as a standing stairs or be used as a stairs leaning on the car, and are either lacking structure stability in use or standing stability on rough or inclined roads that often causes slipping or tumbling of the ladder in use, or being inconvenient or not easy to store or transport after using them. All those disadvantages generally lead to unpredictable dangerous situations and thus poor willingness to use on the user side, and eventually slow down the development of whole relating industry. 
     That results in the needs for an innovative ladder structure that is easy to apply or operate; can be used as a tire ladder putting stably on above a tire and in between the tire and its wheel fender; can be used as an A-shaped ladder standing firmly by a car or in other places; can be securely folded for transportation or storage; can be applied instantly on tires with different tread size and thus can be applied to almost all car types or models; and more importantly, a ladder structure that can instantly stand firmly on rough or inclined ground, roads or object surfaces, thus provide not only a great innovation and improvements to car application and relating industries, but also a more convenient and safer use of cars. 
     SUMMARY OF THE INVENTION 
     The present invention discloses a multifunction ladder structure, it includes a first ladder frame; a second ladder frame; and a pair of combining assemblies that combine the second ladder frame with the first ladder frame, altogether with an optional adjustable band and plural optional foot rods each slides or fixes individually in the first or the second ladder frame. With the implementation of the present invention, the multifunction ladder structure has the special benefit of being easy to install or operate; being able to insert and set firmly in between a tire and the wheel fender as a tire ladder; being able to stand firmly beside a car or places as an A-shaped ladder; with further adding of an adjustable band on the first ladder frame to encircle the tire for even better stability when being used as a tire ladder, or to encircle the second ladder frame for safer storing or transporting; adopting plural foot rods each slides or remains still individually in the first or the second ladder frame, the multifunction ladder structure further applies better on tires of different size, and stands firmly on rough or inclined ground, roads or object surfaces; and with the top rod of the first ladder frame or the further installing of a second stepping unit, the stepping height of the A-shaped ladder can be further raised for even more convenient applications. 
     The present invention provides a multifunction ladder structure, comprising: a first ladder frame that includes a top rod, which is a sturdy U-shaped tube; two first frame tubes, each being fixed firmly on one end to a different end of said top rod, and contains a tube opening on the other end; at least one first stepping unit, being connected firmly in between and joining said two first frame tubes; and two first buckling units, each being fixed firmly on one said first frame tube; a second ladder frame that includes two second frame tubes, being sturdy tubes set in relative and next to said first frame tubes, and contains a tube opening on one end; two second buckling units, each being fixed in relative to a said first buckling unit and firmly on one said second frame tube; and at least one stepping tube, being a sturdy tube connected firmly in between and joining said two second frame tubes; and a pair of combining assemblies, each being fixedly connected to a meeting position of the top rod and a first frame tube, wherein the two combining assemblies combine the second ladder frame to the first ladder frame. 
     Implementation of the present invention at least involves the following inventive steps: 
     1. Easy to set up or to operate. 
     2. Can be used as a tire ladder putting stably on above a tire and in between the tire and its wheel fender. 
     3. Can be used as an A-shaped ladder standing firmly by a car or in other places. 
     4. The U-shaped top rod or the further implemented second stepping unit effectively increases the stepping height when using as an A-shaped ladder, and thus increases the practicality and convenience of using of the multifunction ladder structure. 
     5. With embracing of the tire by a further implemented adjustable band, the multifunction ladder structure can be even more stable when used as a tire ladder. 
     6. The multifunction ladder structure can be further securely folded for transportation or storage by wrapping the second ladder frame close and tight to the first ladder frame with the adjustable band. 
     7. Each of the further implemented foot rods can be adjusted separately that makes the multifunction ladder structure being able to be applied instantly on tires with different tread size and thus can be applied to almost all car types or models. 
     8. With the further implemented foot rods being able to be adjusted separately, the multifunction ladder structure can stand firmly on rough or inclined ground, roads or object surfaces. 
     The features and advantages of the present invention are detailed hereinafter with reference to the preferred embodiments. The detailed description is intended to enable a person skilled in the art to gain insight into the technical contents disclosed herein and implement the present invention accordingly. In particular, a person skilled in the art can easily understand the objects and advantages of the present invention by referring to the disclosure of the specification, the claims, and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The invention as well as a preferred mode of use, further objectives and advantages thereof will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a schematic three-dimensional view of a multifunction ladder structure according to an embodiment of the present invention. 
         FIG. 2A  is a schematic three-dimensional view of a first ladder frame according to an embodiment of the present invention. 
         FIG. 2B  is a schematic three-dimensional view of a second ladder frame according to an embodiment of the present invention. 
         FIG. 2C  is a schematic three-dimensional view of combining assemblies according to an embodiment of the present invention. 
         FIG. 3  is a schematic three-dimensional view of a supporting rod further connected at the joints of the top rod and the two first frame tubes according to an embodiment of the present invention. 
         FIG. 4A  is a schematic three-dimensional view of a multifunction ladder structure further includes plural foot rods according to an embodiment of the present invention. 
         FIG. 4B  is another schematic three-dimensional view of a multifunction ladder structure further includes plural foot rods according to an embodiment of the present invention. 
         FIG. 5A  is a schematic three-dimensional view of the foot rods each contains a positioning protrusion, and each first frame tube and each second frame tube contains plural corresponding positioning holes according to an embodiment of the present invention. 
         FIG. 5B  is another schematic three-dimensional view of the foot rods each contains a positioning protrusion, and each first frame tube and each second frame tube contains plural corresponding positioning holes according to an embodiment of the present invention. 
         FIG. 6A  is a schematic three-dimensional view of a multifunction ladder structure being used as a tire ladder according to an embodiment of the present invention. 
         FIG. 6B  is a schematic three-dimensional view of a multifunction ladder structure being used as an A-shaped ladder according to an embodiment of the present invention. 
         FIG. 7  is a schematic three-dimensional view of a multifunction ladder structure further includes an adjustable band in an embodiment of the present invention. 
         FIG. 8  is a schematic three-dimensional view of the second ladder frame being rotated close to the first ladder frame and enwrapped by an adjustable band according to an embodiment of the present invention. 
         FIG. 9  is a schematic three-dimensional view of a multifunction ladder structure being used as a tire ladder and an adjustable band encircles the tire for even better stability according to an embodiment of the present invention. 
         FIG. 10A  is a schematic three-dimensional view of a multifunction ladder structure further includes a second stepping unit according to an embodiment of the present invention. 
         FIG. 10B  is a schematic three-dimensional view of a multifunction ladder structure further includes a second stepping unit being formed as an extension of the first stepping unit according to an embodiment of the present invention. 
         FIG. 11  is a schematic three-dimensional view of a multifunction ladder structure wherein each of the two first frame tubes being a bending extension to a same direction extended from either end of the top rod according to an embodiment of the present invention. 
         FIG. 12  is another schematic three-dimensional view of a multifunction ladder structure wherein each of the two first frame tubes being a bending extension to a same direction extended from either end of the top rod according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION 
     Embodiments together with illustrating graphs reference are provided hereafter for further understanding and recognizing of the realization of the present invention. 
     Firstly, please refer to  FIG. 1 , in an embodiment of the present invention, is a multifunction ladder structure  100  that comprises a first ladder frame  10 ; a second ladder frame  20 ; and two combining assemblies  30 . 
     Please refer to  FIG. 1  and  FIG. 2A , the first ladder frame  10  of the multifunction ladder structure  100  includes a top rod  11 , two first frame tubes  12 , at least one first stepping unit  13 , and two first buckling units  14 . Wherein said top rod  11 , being a sturdy U-shaped tube, can be made of metal tube, alloy tube or one of durable polymer materials. 
     As can be seen in  FIG. 1  and  FIG. 2A , the first frame tubes  12 , that are aligned to a same direction, are formed in a way that each first frame tube  12  connects in one end to a different end of the top rod  11 , while a tube opening  121  is being formed in the other end of each first frame tube  12 . Further, an included angle is also formed between each of the first frame tubes  12  and the U-shaped top rod  11 . 
     As for the forming material of the first frame tubes  12 , same forming material that forms the U-shaped top rod  11  can be chosen, and in a performing embodiment, the first frame tubes  12  can be integrated in one piece together with the top rod  11 . And at the same time, the two first frame tubes  12  can be formed aligned parallel to each other, or aligned nearly parallel to each other, wherein nearly parallel means the included angle between the two first frame tubes  12  being zero degree or less than 5 degrees. 
     As shown in  FIG. 1  and  FIG. 2A , the distance between the two first frame tubes  12  can be formed that with the tube opening  121  pointing at the tire  810 , the first ladder frame  10  inserts freely in the space in between the tire  810  and its wheel fender  820  and rest on the tire  810 . 
     Please refer again to  FIG. 1  and  FIG. 2A , at least one first stepping unit  13  is being connected firmly in between and joins said two first frame tubes  12 , wherein the first stepping unit  13  can be a stepping pedal formed by a sturdy mesh tread, a sturdy tread pedal, a sturdy tread pedal with plural through holes, or at least two tubes placed in parallel to each other to form a sturdy tread surface for stepping on. Further, for safer use in applications, the first stepping unit  13  can be formed of one of anti-slip materials. 
     As also shown in  FIG. 1  and  FIG. 2A , the first buckling units  14  are formed such that each being connected to a first frame tube  12 . Said first buckling units  14  can be a linking rod, a hook, a bendable linking rod, a bendable hook, or a webbing ribbon with at least a buckle or a buttonhole. 
     Please refer then to  FIG. 1  and  FIG. 2B , the second ladder frame  20  of the multifunction ladder structure  100  includes two second frame tubes  21 , two second buckling units  22 , and at least one stepping tube  23 . 
     As shown in  FIG. 1  and  FIG. 2B , the second frame tubes  21  are set corresponding to the first frame tubes  12  and can also be sturdy tubes. The two second frame tubes  21  can also be aligned parallel or nearly parallel to each other. Further, a tube opening  211  is being formed at one end of each second frame tube  21 . 
     As for the thickness or size of any of the second frame tubes  21 , same thickness value or size as the corresponding first frame tube  12  can be chosen. While the distance of the two second frame tubes  21  at any position can also be chosen to be same as the distance of the two first frame tubes  12  at a corresponding position. 
     As also shown in  FIG. 1  and  FIG. 2B , the second buckling units  22  are formed such that each second buckling unit  22  being connected to a second frame tube  21 , and in the multifunction ladder structure  100 , each said second buckling unit  22  is either linked together with or detached from a corresponding first buckling unit  14 . 
     That is to say, the second ladder frame  20  can be further connected with the first ladder structure  10  with the two second buckling units  22  being linking together with the two corresponding first buckling units  14 . 
     Please refer again to  FIG. 1  and  FIG. 2B , the stepping tube  23 , being a sturdy tube connected firmly in between and joining the two second frame tubes  21 , functions as a stepping stair of the second ladder frame  20 . 
     Please refer now to  FIG. 1  and  FIG. 2C , the two combining assemblies  30  of the multifunction ladder structure  100 , each being fixedly connected to a meeting position of the top rod  11  and a first frame tube  12 , combine the second ladder frame  20  to the first ladder frame  10  in a way that the second ladder frame  20  being either rotating at the combining assemblies  30  relative to the first ladder frame  10 , or connected firmly on the first ladder frame  10  at the combining assemblies  30 . 
     As such, the multifunction ladder structure  100  is formed when combining the second ladder frame  20  with the first ladder frame  10  by the combining assemblies  30 . The second ladder frame  20  is then firmly fixed after rotating at the combining assemblies  30  with a required included angle with the first ladder frame  10  to make the multifunction ladder structure  100  a tire ladder or an A-shaped ladder. 
     Wherein the combining method can be that the second ladder frame  20  is being riveted or screwed and being rotating or securely fixed at the combining assemblies  30  and is thus fixedly connected to the first ladder frame  10  by the combining assemblies  30 . 
     Next, please refer to  FIG. 3 , a supporting rod  40  can be further connected at the joints of the U-shaped top rod  11  and the two first frame tubes  12  to make the multifunction ladder structure  100  even more stable, firm and durable. 
     And as shown in  FIG. 4A  and  FIG. 4B , with or without a supporting rod  40 , the multifunction ladder structure  100  can further include plural foot rods  50 , wherein each foot rod  50  is being placed in one first frame tube  12  or in one second frame tube  21  through the tube opening  121  or the tube opening  211  and being either sliding or fixedly contained in the first frame tube  12  or the second frame tube  21 . 
     In embodiments, the foot end of each foot rod  50  extends outside the tube opening  121  or the tube opening  211 , while at the same time the forming material of the foot end can be chosen from materials with greater friction or better elasticity for better standing stability of the multifunction ladder structure  100  and helping to prevent scratching the tire  810  or car body when inserting it to the spacing in between the tire  810  and the wheel fender  820 . 
     And as shown in  FIG. 5A  and  FIG. 5B , a positioning protrusion  60  can be formed on each of the foot rods  50 , and, at the same time, plural positioning holes  70  corresponding to the positioning protrusion  60  are being formed on each first frame tube  12  and each second frame tube  21 . Each foot rod  50  can thus slide or remain still in a first frame tube  12  or a second frame tube  21  with the positioning protrusion  60  slides in the first frame tube  12  or the second frame tube  21  or stops at a positioning hole  70 . 
     As such, each foot rod  50  can be independently sliding or remaining still in a certain position in a first frame tube  12  or a second frame tube  21  making each foot rod  50  extends a different required length outside the first frame tube  12  or the second frame tube  21 , and thus making the multifunction ladder structure  100  be able to stand firmly even on rough or inclined ground, roads or object surfaces and apply better on tires of different size or with different tread size, and thus can be applied to almost all car types or models. 
     And as shown in  FIG. 1  and  FIG. 6A , the second ladder frame  20  can be securely fixed at the combining assemblies  30  possessing an included angle θ greater than 90 degrees to the first ladder frame  10  and forms a tire ladder for car applications together with the first ladder frame  10 . 
     While as shown in  FIG. 1  and  FIG. 6B , the second ladder frame  20  can also be securely fixed at the combining assemblies  30  and forms an A-shaped ladder together with the first ladder frame  10 . At this time, each second buckling unit  22  linking connects to one first buckling unit  14  and helps to form an even more stable A-shaped ladder for placing beside a car, a tire or other places for different applications. 
     In the embodiments, the method of connecting the first frame tubes  12  to the U-shaped top rod  11  can be any connection that prevents the U-shaped top rod  11  from interfering the second ladder frame  20  when the multifunction ladder structure  100  is being formed as a tire ladder; while at the same time, the U-shaped top rod  11  provides a stepping surface that is level or almost level for increasing the stepping height provided when the multifunction ladder structure  100  is being formed as an A-shaped ladder. 
     Please refer now to  FIG. 7 , an adjustable band  80  can further be fixedly attached to the first ladder frame  10  of the multifunction ladder structure  100 , wherein the adjustable band  80  is formed across the first frame tubes  12  and one end of the adjustable band  80  is fixedly attached to one first frame tube  12  and the other end of the adjustable band  80  is fixedly attached to the other first frame tube  12 , with the length or tightness of the adjustable band  80  being adjusted by the user when adopted for applications. 
     While as shown in  FIG. 8 , when storing or transporting the multifunction ladder structure  100 , the second ladder frame  20  and the first ladder frame  10  can be folded close to each other with the adjustable band  80  encircles tight the second ladder frame  20  such that the second ladder frame  20  does not accidently evert from the first ladder frame  10  for safer and more convenient transportation or storage. 
     And as shown in  FIG. 9 , when the multifunction ladder structure  100  is formed and used as a tire ladder and being inserted into the spacing between a tire  810  and its wheel fender  820 , the adjustable band  80  on the first ladder frame  10  can further be used to encircle the tire  810 , or more specifically the upper part of the tire  810 , on its surface, preventing the first ladder frame  10  and thus the whole multifunction ladder structure  100  from slipping out the tire  810  for even better stability and safety of use. 
     Please refer then to  FIG. 10A , the multifunction ladder structure  100  can further include a second stepping unit  90  which can be formed across the U-shaped top rod  11 . As such, when the multifunction ladder structure  100  is being used as an A-shaped ladder, the second stepping unit  90  provides a safer and easier stepping area together with the U-shaped top rod  11  to increase effectively the overall stepping height of the A-shaped ladder. 
     Said second stepping unit  90  can also be a stepping pedal formed by a sturdy mesh tread, a sturdy tread pedal, a sturdy tread pedal with plural through holes, or at least two tubes placed in parallel to each other to form a sturdy tread surface, and for safer use in applications, the second stepping unit  90  can also be formed of one of anti-slip materials. 
     And as shown in  FIG. 10B , the second stepping unit  90  can also be an extension from the first stepping unit  13 , the production complexity of the multifunction ladder structure  100  is then reduced and the structure strength and durability of the first stepping unit  13  and the second stepping unit  90  are also increased. 
     Further, as shown in  FIG. 11  and  FIG. 12 , in all embodiments, the two first frame tubes  12  in the multifunction ladder structure  100  can be bending extensions from both ends of the U-shaped top rod  11  in the same direction, that is to say, one first frame tube  12  is a bending extension to a direction extended from one end of the top rod  11 , and the other first frame tube  12  is a bending extension to the same direction extended from the other end of the top rod  11 , thus providing not only the benefit of easier preparation of materials and smoother outlook, but also an enhancement of structure strength due to the reducing number of junctions in the multifunction ladder structure  100 . 
     In conclusion, as shown in the embodiments and in the illustrating figures  FIG. 1  to  FIG. 12 , with the special improved structural characteristics, multiple improvements as follows, which cannot be achieved by known existing solutions, can be achieved by the multifunction ladder structure  100  of the present invention: being easy to set up or to operate; can be used as a tire ladder putting stably on above a tire  810  and in between the tire  810  and its wheel fender  820 ; can be used as an A-shaped ladder standing firmly by a car or in other places; with embracing of the tire  810  by a further implemented adjustable band  80 , the multifunction ladder structure  100  can be even more stable when used as a tire ladder, and can be further securely folded for transportation or storage by wrapping the second ladder frame  20  close and tight to the first ladder frame  10  with the adjustable band  80 ; each of the further implemented foot rods  50  can be adjusted separately to make the multifunction ladder structure  100  being able to be applied instantly on tires with different tread size and thus can be applied to almost all car types or models, and being able to stand further firmly on rough or inclined ground, roads or object surfaces; and the U-shaped top rod  11  or the further implemented second stepping unit  90  effectively increase the stepping height when using as an A-shaped ladder, and thus increase the practicality and convenience of using of the multifunction ladder structure  100 . 
     The embodiments described above are intended only to demonstrate the technical concept and features of the present invention to enable a person skilled in the art to understand and implement the contents disclosed herein. It is understood that the disclosed embodiments are not to limit the scope of the present invention. Therefore, all equivalent changes or modifications based on the concept of the present invention should be encompassed by the appended claims.