Abstract:
A securing apparatus that releasably secures two or more mechanical elements is provided. The securing apparatus may be attached to one mechanical element and include abutment surfaces that abut at least one additional mechanical element. Forces exerted by the at least one additional mechanical element and the securing apparatus on each other serve to maintain the securing apparatus in a locked position. The securing apparatus may include a locking member that includes a protruded portion that extends at least partially beneath the securing apparatus and at least one mechanical element. A pull-ring may be provided to rotate the locking member and release the mechanical elements being secured. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained herein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims.

Description:
FIELD OF THE INVENTION 
   The present invention generally relates to a securing apparatus releasably securing two or more mechanical elements, and a method of operation. 
   BACKGROUND OF THE INVENTION 
   Devices for securing mechanical elements are known. Such devices include clamps, nuts and bolts, screws, staples, rivets, etc. Some of these devices require maintaining multiple mechanical elements in a particular relation to ensure that the mechanical elements are secured in a desired manner. This may be difficult if there is only one operator securing the mechanical elements. For example, an operator may be required to hold a bolt with one hand and/or a tool while using another hand or tool to rotate a nut onto the bolt. This may be awkward depending on a location of the bolt and nut. 
   Additional devices may be required to assist an operator in maintaining the mechanical elements in a desired position. For example, there may be difficulty in orienting the elements in a required securing position. Therefore, the operator may require other devices to assist in maintaining one or more of the mechanical elements in the desired position. Such an additional devices can include clamps, pliers or other gripping devices. Additional disadvantages include the amount of time required for securing the components, slippage and the requirement for sufficient space for working to secure the mechanical elements as desired. 
   Moreover, operation of securing elements requiring complexity or dexterity for operation can be unnerving to use where speed is desired. For example, a screw and nut type of securing apparatus can be unnerving to use, even if a relatively short period is required to operate the screw and nut mechanism, since it requires threading the nut on the bolt and then turning the nut (or bolt) to secure the mechanism. 
   Therefore, there exists a need for a securing apparatus that optionally is self-orienting, and relatively easy to operate and release. 
   SUMMARY OF THE INVENTION 
   The present invention alleviates to a great extent the disadvantages of known securing apparatus, by providing a securing system releasably securing two or more mechanical elements in a relatively fixed orientation. One embodiment of the present invention includes a securing apparatus that can be used with a foldable bicycle to releasably secure one or more of its elements. However, it will be appreciated that the apparatus can be used to releasably secure any type of elements. 
   The securing apparatus includes a substantially rigid member, which is referred to herein as a plate or hinged plate. The plate member is rotatably or pivotally mounted on at least one of the mechanical elements such as using a hinge assembly. The plate has abutment surfaces. The abutment surfaces of the plate are adapted to engage corresponding engagement surfaces of one or more of the components being secured—other than the component(s) to which the plate is hingedly mounted. Preferably the securing apparatus includes a biasing mechanism that biases the plate towards an engaged position. 
   Another aspect of the invention is a locking assembly that secures the plate and the component in the locked position. The locking assembly can include a locking member, which includes an engagement portion extending therefrom. The engagement portion overlaps a portion of at least one of the abutment surfaces in the locking or secured position. That way, the engagement surface(s) and corresponding abutment surface(s) are retained in position. Likewise in the locked position, preferably the abutment and corresponding engagement surfaces exert opposite and opposing forces on one another, thereby resulting in self-orienting biasing forces. A locking member biasing assembly optionally is provided to bias the locking member in the securing position. 
   In another aspect of the invention, the securing apparatus is operated to disengage, by rotating the locking member such that its engagement portion is clear of the corresponding abutment surface. Then the hinged plate is rotated about its hinge such that the abutment surface(s) and corresponding engagement surface(s) are clear of one another. 
   In one embodiment of the invention, the securing apparatus is used to secure two or more components of a foldable bicycle in a riding position. For example, the hinged plate may be rotatably mounted by a hinge assembly to one or more top tubes of a foldable bicycle adjacent the seat tube. The hinged plate is secured to the top tube(s) such that the hinge plate may be rotated from the secured position to a clear, i.e. unlocked position. The locking member in this embodiment is rotatably attached to the hinged plate by a pivot assembly. The locking member includes a protruding engagement portion such that when the securing apparatus is in the secured position, the engagement portion extends at least partially beneath the at least one of the abutment surfaces of the hinged plate. The locking member also includes a biasing assembly that biases the engagement portion of the locking member in a direction toward a locking position. The locking member also may mount a grappling structure, such as a pull-ring. The pull-ring enables an operator to rotate the locking member about the pivot between the locked and unlocking positions. To releasably secure seat stays of the foldable bicycle, abutment surfaces of the hinged plate are aligned to mate with corresponding engagement surfaces at the ends of the seat stay(s) of the foldable bicycle. The hinged plate is moved downwardly toward the ends of the seat stays. The forces exerted by the abutment portions and the corresponding engagement surfaces of the seat stay(s) on each other serve to lock the securing apparatus in place. In a preferred embodiment, the surfaces are slightly angled off perpendicular so as to further secure and orient their relative positions. To release the securing apparatus, an operator optionally rotates the locking member in a direction away from the hinged plate until the engagement portion is no longer beneath the hinged plate. The locking member and hinged plate together are directed in an unlocking direction (for example upwards) to cause the hinged plate to rotate about its hinge to a disengaged position. This causes the abutment surface(s) of the hinged plate to disengage from the corresponding surface(s) of the seat stays, allowing the seat stays to move. Thus it is seen that the seat stays are releasably secured in a fixed relation to the top tube(s) and/or seat and/or seat tube and/or frame of the folding bicycle. 
   Although a preferred embodiment of the present invention is used in conjunction with a foldable bicycle, it should be appreciated that the present invention may be used for any structure where it is desired to releasably secure two or more mechanical elements. For example, the securing apparatus may be used to releasably secure components in foldable motorcycles, strollers, trolleys, box covers, container door locks, specialty furniture, windows, doors, military equipment, airplanes or other applications where two or more mechanical elements may be releasably secured. 
   The securing apparatus preferably is structured for operation without using any tools and may securely lock the two or more mechanical elements in a desired position. 
   These and other features and advantages of the present invention will be appreciated from review of the following detailed description of the invention, along with the accompanying figures in which like reference numerals refer to like parts throughout. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side view of an embodiment of a foldable bicycle in accordance with the one embodiment of the present invention; 
       FIG. 2  is a side view of a securing apparatus for a foldable bicycle in accordance with the one embodiment of the present invention; 
       FIG. 3  is a cross-sectional view of the securing apparatus taken along line  3 - 3  as shown in  FIG. 2 , in accordance with the one embodiment of the present invention; 
       FIG. 4  is a top perspective view of a hinged plate of a securing apparatus in accordance with the one embodiment of the present invention; 
       FIG. 5  is a top perspective view of a locking member of a securing apparatus in accordance with the one embodiment of the present invention; 
       FIG. 6  is a top cross-sectional view of the locking member shown in  FIG. 5 , in accordance with the one embodiment of the present invention; 
       FIG. 7  is a top perspective view of a securing apparatus in a locked position on a foldable bicycle in accordance with the one embodiment of the present invention; 
       FIG. 8  is a side view of a securing apparatus in an unlocked position mounted on a foldable bicycle in accordance with one embodiment of the present invention; 
       FIG. 9  is a side view of a seat stay connecting rod in accordance with the one embodiment of the present invention; 
       FIG. 10  is a side view of an end portion of a seat stay of a foldable bicycle in accordance with the one embodiment of the present invention; 
       FIG. 11  is a top view of an end portion of a seat stay of a foldable bicycle in accordance with the one embodiment of the present invention; and 
       FIG. 12  is a block diagram of a method of assembling a portion of a foldable bicycle using a securing apparatus in accordance with the one embodiment of the present invention. 
   

   It will be recognized that some or all of the Figures are schematic representations for purposes of illustration and do not necessarily depict the actual relative sizes or locations of the elements shown. 
   DETAILED DESCRIPTION OF THE INVENTION 
   In the following paragraphs, the present invention will be described in detail by way of example with reference to the drawings. Throughout this description, the preferred embodiment and examples shown should be considered as exemplars, rather than as limitations on the present invention. As used herein, the “present invention” refers to any one of the embodiments of the invention described herein, and any equivalents. Reference to various feature(s) of the “present invention” throughout this document does not mean that all claimed embodiments or methods must include the referenced feature(s). 
   The present invention relates to a securing apparatus (also referred to as “assembly”) releasably securing two or more mechanical elements. According to one embodiment of the present invention, the securing apparatus may be used to releasably secure portions of a foldable bicycle to one another. However, it should be noted that the securing apparatus of the present invention may be used any application in which it is desired to secure two or more elements to one another. Examples of applications of the securing apparatus is in securing elements in motorcycles, strollers, trolleys, box covers, container door locks, specialty furniture, windows, doors, military equipment, airplanes or other applications where two or more mechanical elements may be releasably secured. 
   An example of a foldable bicycle  10  including one example of a securing apparatus  20  of the present invention is illustrated in  FIG. 1 . The foldable bicycle  10  can have any construction. As one example the bicycle has a frame including frame elements such as optionally a down tube  30  assembly that optionally may include spatially separated tubes  30 A,  30 B, a seat tube  40  corresponding to the tube beneath the seat  45  and into which the seat post  48  can slidably fit, a top tube assembly  50  optionally including separated top tubes, and a bearing tube  60 . One end of the top tube  50  is attached to the bearing tube  60 , as is one end of the down tube assembly  30 . If a single down tube  30  is used, the single down tube may be provided with a split in the middle as well in effect creating a split down tube. The split may be shaped to accommodate a front wheel of the foldable bicycle  10  when the front wheel is in a folded position. 
   The foldable bicycle  10  may also include a handlebar assembly  70  that is foldable. The handlebar assembly is rotatably mounted to the bearing tube  60 , as is the front wheel assembly  80 . Optionally the front wheel assembly  80  is foldable in some fashion so as to bring the front wheel  85  into closer proximity to the down tube  30  than it is in the unfolded position illustrated in  FIG. 1 . In one embodiment the front wheel assembly  80  is foldable such that the front wheel  85  can be positioned adjacent the down tube  30 , such as between the two tubes  30 A and  30 B. The down tubes  30 A,  30 B preferably have a gap between them, which is sufficiently wide to accommodate a front wheel of the foldable front wheel assembly  80 . A foldable rear wheel assembly  90  is also provided, which is foldable such that the rear wheel  95  is moved closer to the seat tube  40  than it is when in the unfolded position. Although a single top tube  50  is shown in  FIG. 1 , spatially separated top tubes also may be used. The foldable rear-wheel assembly  90  may include one or more seat stays  100 A,  100 B. 
   In an example discussed herein, the securing apparatus  20  is used to releasably secure a seat stay assembly  100  (also referred to as the “seat stays”  100 ,  100 A and/or  100 B or “seat stay”) to the bicycle frame, such as at seat tube  40  and/or the top tube assembly  50  and/or the downtube assembly  30 . In brief summary of the operation of this particular embodiment, in order to fold the rear wheel assembly  90 , the securing apparatus  20  is operated to release the seat stay assembly  100  from a fixed relation connection to the frame of the bicycle (and the seat tube  40  and/or the top tube assembly  50 ) to allow the wheel  95  to rotate about a pivot location (illustrated with reference number  105 ) into a fold position. In order to restore the bicycle  10  to a riding position, the seat stays  100 A and  100 B can be restored to a secure position using the securing apparatus  20 . It should be noted that the pivot location can be situated at any location wherein the rear wheel  95  can be moved relative to the frame of the bicycle. 
     FIG. 2  is a side view of an embodiment of a releasable securing apparatus  20  in a locked position used in conjunction with a foldable bicycle  10  according to one embodiment of the invention. The securing apparatus  20  includes a securing member  110 , which also is referred to as a “rigid member”, a “plate”, a “plate member” or a “hinged plate member”. This securing member  110 , refers to any element with sufficient structural strength to secure the securing apparatus  20  and withstand the forces applied during typical or expected use. Although a particular example of a structure is used herein, it should be understood that other structural shapes and arrangements can be used. The hinged plate member  110  optionally has a raised portion  120  and a biasing assembly mounting location  130 , also called a first eyelet  130 , hinged plate biasing member  140 , hinge assembly  150 , abutment surfaces  160 , locking assembly including locking member  170 , and engagement surface  180  (also called a “pull-ring” in the illustrated embodiment). The seat tube  40  optionally has a biasing assembly mounting location  200 , which will be referred to as second eyelet  200 . The foldable bicycle  10  may include any known seat clamp  210  and seat  45 . The foldable bicycle  10  may also include one or more seat stays  100  having an optionally curved connector portion  230 . The connector  230  engages an mounting rod  240 . The mounting rod  240  is preferably secured to the seat tube  40  of the foldable bicycle  10  by, for example, a weld, although other securing devices and locations may be used. 
   A hinge assembly  150  is provided to rotatably or pivotally mount the plate  110  to one or more of the elements being secured by the securing apparatus  20 . In the foldable bicycle embodiment, the hinge assembly  150  is used to secure the plate  110  to the frame of the bicycle  10 , such as on one or more of the top tubes  50 , seat tube  40  or the down tube assembly  30 . In the illustrated embodiment, the hinge assembly  150  hingedly connects the plate  110  to the top tube assembly  50 . The hinge  150  enables the hinged plate  110  to rotate in directions toward and away from the top tubes  50  described in further detail below. 
   A biasing assembly is provided to bias the plate  110  in a desired, i.e. locked position. In the illustrated embodiment, a spring  140  is used to provide the biasing force, although it should be understood that any form of biasing device may be used, such as linear or torsional springs (leaf springs), magnetic elements and so on. In the illustrate embodiment, the plate  110  includes a mounting location for one end of the biasing member, i.e. spring  140 . The spring is attached to the plate  110  at a first aperture  130 , also referred to as a first eyelet  130  situated on the raised portion  120 . It should be understood that the biasing assembly my be situated to link with the plate  110  at any location or locations that can provide sufficient biasing force to bias the plate  110  in the desired direction. In the illustrated embodiment, the spring  140  is anchored at another end of the spring to the seat tube  40 . Again, it should be understood that any desired anchoring location may be used, such that a sufficient anchoring strength is provided adequately to anchor the biasing assembly. In the illustrated embodiment, the spring is mounted at mounting location  200  on the seat tube  40 . This mounting location  200  eyelet is referred to as the second eyelet. In the illustrated embodiment, the plate  110  is hinged at location  150  whereby the biasing assembly exerts a torsional force on the plate  110  biasing it in the desired direction. In the illustrated embodiment, the direction is rotationally generally downwards, toward the top tube assembly  50  about the hinge  150 . It should be noted that although a rotational biasing direction is illustrated, whereby the biasing assembly imparts the biasing force at a single location (the first eyelet  130 ) spatially separated from the corresponding pivot location, about hinge  150 , in other embodiments, multi-point forces can be provided by the biasing assembly. For example, the biasing assembly can alternatively provide force at two or more separated location such as to provide a linear bias in a desired direction, or the rotational bias already discussed, by way of example. 
   In one embodiment, the hinged plate  110  optionally includes abutment surfaces  160  that engage corresponding engagement surfaces  165  on other elements. Preferably each of the abutment surfaces  160  is a generally flat surface that has a matching (i.e. opposite) angle to that of the corresponding engagement surface  165 . The angle selected (illustrated as angle “A” in  FIG. 4 ) can be any angle, but preferably is slightly off of perpendicular with respect to a corresponding adjacent surface, illustrated with reference numbers  163  and  164  in  FIG. 4 . Preferably the angle is between 80 and 100 degrees, although it should be appreciated that any desired angle can be used, even perpendicular or angles substantially off of perpendicular, so long as the corresponding end surfaces  165  are provided at a mating orientation, whereby they exert opposing forces upon one another when the plate is in a locked position. The abutment surfaces  160  can be at any location on the hinged plate  110  such that they can impinge upon the corresponding end surfaces  160 . In the illustrated embodiment, they are at respective ends or extension members  270 A,  270 B. 
   In the illustrated embodiment, the corresponding end surfaces  165  are provided on respective ends of seat stays  100 . The end surfaces  165  of the seat stays  100  also include the optionally curved connector portion  230 , which can have any shape and optionally includes dropouts that engage the mounting rod  240 . As illustrated in greater detail in  FIGS. 10 and 11 , the inner surface portion  235  of the connector portion  230  is shaped to engage and retain the seat stays in fixed relation to the mounting rod  240  when locked in such as using the securing apparatus  20 . The outer surface portion  237  in the illustrated embodiment includes a substantially curved shape. The mounting rod  240  can be fixedly attached to the bicycle frame in any fashion. In the illustrated embodiment, it is attached to the seat tube  40 , such as by welding, or any other fastening technique or apparatus. 
   The mounting rod  240  preferably also includes recesses  300  to assist in positioning the connectors  230  when they engage the rod  240 . The seat stays  100  preferably form part of a foldable rear-wheel assembly  90  of the foldable bicycle  10 . When the foldable bicycle  10  is an unfolded or a riding position, the connecting portion  230  connects to the mounting rod  240  such as by positioning each of the drop-outs  235  into the corresponding recess  300 . The abutment surfaces  160  of the plate  110  abut the corresponding end surfaces  165  of the seat stays  100  and the opposed forces exerted by the end abutment surfaces  160  and the seat stays  100  (such as at end surfaces  165 ) on each other serve to maintain the securing apparatus  20  in a locked position. It should be noted that the outer surface  237  can be shaped to assist in positioning the seat stays  100  into the secured position. In the illustrated embodiment, the outer surface(s)  237  are curved so as to slidably engage the securing apparatus  20  at or near the abutment surfaces  160 . 
   Optionally a locking assembly  175  including locking member  170 , and related apparatus described below, is provided to secure the securing apparatus  20  in a locked position. The locking member  170  includes engagement surface  250  (shown in  FIG. 3 ) that is positionable at least partially adjacent (for example, beneath as in the illustrations) at least one of the abutment surfaces  160 . The locking member  170  is movably mounted such that the engagement surface  250  can be moved to its resting position adjacent at least one of the abutment surfaces  160 , to an unlocking position where it is clear of the abutment surfaces  160 . Preferably the locking member  170  is rotatably mounted such that the engagement surface  250  can be rotated into and out of its locking position. In the illustrated embodiment, the locking member  170  is pivotally mounted to the locking plate  110 , such as at the pivoting assembly  289  of the locking assembly  175 . The locking plate  110  is hingedly mounted to one of the components via hinge assembly  150  providing for motion in a first rotational direction and the locking member  170  is pivotally mounted to the locking plate  110  in a second rotational direction via the pivoting assembly  289 . In the illustrated embodiment, the first and second rotational directions are orthogonal or perpendicular to one another, although it should be understood that different angular relationships may be selected so long as the abutment surfaces  160  of the locking plate  110  can be moved and the locking member  170  can be moved into and out of position. Likewise other movable mounting structures, allowing either the locking member  170  and/or the locking plate  110  to move as desired can be used, such as linear or sliding linkages. It also should be noted that “pivoting”, “hinge” and “rotating”, and “pivotally”, “hingedly” and “rotatably” are used in this description interchangeably; the word “hinge assembly”  150  and “pivoting assembly”  289  are described with different words so as to distinguish them, but use of the different words does not mean that they are performing different functions in different ways, although optionally different mechanisms may be used to achieve the hinged connections. 
   In the illustrated embodiment, the pivoting assembly  289  includes a screw or hinge pin (not shown) is inserted through aperture  285  in hinge post  287  and a corresponding aperture  288  in hinge mount  280 , providing a pivotable mount of the locking member  170  to the plate  110 . In the fully locked position of the securing apparatus  20 , the locking member is positioned so that its engagement surface  250  is slid adjacent at least one of the locations where the abutment surfaces  160  abut corresponding respective end surfaces  165 . For example, the engagement surface  250  of the locking member optionally can extend to overlap partially with one of the abutment surfaces  160  and corresponding end surface  165  or alternatively can overlap fully with one of the abutment surfaces  160  and corresponding end surface  165 , or alternatively can extend to overlap with two of the abutment surfaces  160  and corresponding two end surfaces  165  and so on. Any size or shape engagement surface  250  can be provided that will extend sufficiently adjacent the locking plate  110  such that it acts to retain the plate  110  in a locked position. Thus, the engagement surface  250  of the locking member  150  aids in maintaining the securing apparatus  20  and the seat stays  100  in a desired position by reducing movement of the hinged plate  110 , and the seat stays  100 . 
   It should be noted that in an alternative embodiment of the invention, a locking mechanism including locking member  170 , engagement surface  250  and associated optional hinge and biasing elements are not required. Instead this alternative embodiment, the plate  110 , and the forces applied by surfaces  160  and  165  on each other are sufficient to secure the components being releasably secured. 
     FIG. 3  illustrates a cross-section of the securing apparatus  20  as taken along line  3 - 3  shown in  FIG. 2 . In this illustration, the top tube assembly  50  includes tube  50 A and  50 B. In that illustration, the engagement portion  250  (also called “engagement surface”) of the locking member  170  extends at least partially beneath plate  110 . The locking member  170  optionally includes a grappling structure  180  that a user can use to assist in grasping and moving the locking member  170 . Optionally the grappling structure is a pull ring  180 , which is mounted via an optional third eyelet  260 . The pull ring  180  optionally can be used to assist an operator in grasping and rotating the locking member  170  about a pivot axis. Although an eyelet  180  and ring are illustrated as one example of a structure to assist the operator in grasping and pulling on the locking member, it should be appreciated that any grappling structure may be provided, such as tabs, hooks, indentations, etc., that allows an operator to grasp and move the locking member  180  about its pivot axis. In one embodiment, the locking member  170  is spring biased so that the engagement portion  250  is biased towards the plate  110 , i.e. towards its engaged, or locked, position. An example of a biasing mechanism  290  is illustrated in  FIG. 6 , in which a spring is used to push one end of the locking member  170  away from the locking plate  110 , wherein the spring engages the locking member  170  on the opposite side of the pivot axis from the engagement portion  250 , thereby biasing the engagement portion in the opposite direction, namely towards the plate  110 . It should be appreciated that any type of biasing assembly can be used that biases the locking member in the desired direction. For example torsional forces can be applied via leave springs mounted in a desired location, or in the pivot assembly. Alternatively, linear biasing forces can be applied at any desired location, such as illustrated, or alternatively on the other side of the pivot assembly, i.e. the engagement portion  250  side, whereby the linear bias would be applied towards the plate  110 . The pivot biasing assembly  290  assists in maintaining the engagement portion  250  remain at least partially beneath the mechanical elements being releasably secured when in a locked position. This is achieved because the pivot biasing member  290  urges the engagement portion  250  of the locking member  170  adjacent the pull-ring towards the hinged plate  110 . 
   Illustrations showing the operation of an illustrated embodiment of the securing apparatus of the present invention can be found in  FIGS. 7 and 8 .  FIG. 7  shows a perspective view of the securing apparatus  20  in a locked position, and  FIG. 8  illustrates the securing apparatus  20  in an unlocked position. When in the locked position, the abutment surfaces  160  of the hinged plate  110  abut corresponding engagement surfaces  165 . The protruding engagement portion  250  of the locking member  170  extends beneath one of the abutment surfaces  160  in the illustration. An end portion of the engagement portion  250  is shown in solid lines extending into the space between the two illustrated abutment surfaces  160 . A portion of the engagement portion that is beneath the abutment surface (and portion of seat stay  100  and its engagement surface  165 ) is illustrated in broken lines. The pivot biasing assembly  290  attaches to a portion of the locking member  170  that is on the opposite side of the pivot assembly (shown with number  289 ) from the engagement portion  250 . The biasing assembly  290  also is mounted to the plate  110 . The force exerted is away on the locking member  170  from the plate  110  and thereby biasing the engagement portion  250  towards and beneath the abutment surface  160  (and seat stay  100  and engagement surface  165 ), acting to bias at least a portion of the engagement surface  250  in the locking position. The pull-ring  180  may be used to rotate the locking member  170  about the pivot mounting assembly  289 . By rotating the locking member  170  sufficiently away from the hinged plate  110 , the engagement surface  250  no longer extends beneath the seat stays  100  and the hinged plate  110 . The securing apparatus  20  may then be released as described in further detail below. 
   The locking member  170  is in an unlocking position wherein the engagement surface  250  is not located beneath the abutment surfaces  160  (and their corresponding extension members  270 A,  270 B of the hinged plate  110 . This may be performed using the pull-ring  180  as described above. In order to disengage the securing apparatus  20 , the locking member  170  is moved to an unlocked position, and the hinged plate  110  is disengaged from the linked component. In the illustrated embodiment, the linked component includes the seat stays  100 . In disengaging the securing apparatus, the hinged plate is rotated about hinge assembly  150  so that the abutment surfaces  160  disengage their corresponding engagement surfaces  165  on the seat stays  100 . This allows the seat stays to move freely in their natural folding direction, which in the illustrated embodiment is towards and overlapping with seat tube  40 . Thusly the folding force of the seat stays  100  and their rear wheel assembly  90  is released to move in the direction previously blocked by the locking plate  110 , and specifically engaged by surfaces  160 . 
   In the unlocked position, the hinged plate  110  may be rotated in an upward direction about the hinge  150 . The hinged plate  110  may be rotated such that abutment surfaces  160  are no longer in contact with end portions of the seat stays  100 . Alternatively, the abutment surfaces  160  may abut the end portions of the seat stays, however, the hinged plate  110  may be fairly easily rotatable because the abutment surfaces  160  and the seat stays  100  exert only minor forces on each other. 
     FIGS. 10 and 11  provide exemplary detail views of a seat stay  100  of a foldable bicycle having a connecting portion  230  according to one embodiment of the invention. The connecting portion  230  is preferably inserted into the notches  300  of the connecting rod  240 . The notches  300  assist to maintain the connecting portion  230  in a desired position. 
   The method of the present invention now will be described in greater detail with reference to  FIG. 12 .  FIG. 12  illustrates a method of assembling a foldable bicycle  10  using a securing apparatus  20  according to one embodiment of the present invention. In step  1010 , the seat stays  100  of the foldable bicycle are rotated in a direction toward a seat tube  40  of the foldable bicycle about the pivot axis  105  of the rear wheel assembly  90 . In step  1020 , connecting portions  230  of the seat stays  100  are coupled with a connecting rod  240 , such as in the engagement recesses  300 . In step  1030 , the locking member  170  is rotated about its pivot axis in the pivot assembly  289  such that the engagement portion  250  is clear of the abutment surfaces  160 , putting the assembly in condition for moving into a locked position. This may be performed by pulling on pull-ring  180  with sufficient force to overcome the bias force from biasing assembly  290 , or alternatively by impinging on surface  237 . In step  1040 , the hinged plate  110  of the securing apparatus  20  is rotated about its hinge  150  such that abutment surfaces  160  are urged into mating position with corresponding engagement surfaces  165  of the seat stays  100 . This can be accomplished by allowing the spring force exerted by biasing mechanism  140  to operate to urge the plate  110  into the desired orientation, and alternatively the operator can assist this motion, such as by pulling downward on ring  180  or by pushing downward on the plate  110 . This step is continued until the securing apparatus reaches a locked position. As a result of this operation, the seat stays  100  and the plate  110  exert linear opposing forces upon one another. In step  1050 , the locking member  170  is rotated about its pivot axis in the pivot assembly  289  such that the engagement portion  250  is under at least one of the abutment surfaces  160 , thereby locking the plate  110  from rotating away from the engagement position where surfaces  160  and  165  abut one another. This can be performed by releasing the pull-ring  180  allowing the biasing forces imparted by biasing assembly  290  to act to pivot the locking member about its axis of rotation. In some instances, an operator may push on the ring  180  or a portion of the locking member  170  to assist its movement into the locking position. It should be appreciated that the method steps discussed herein can be performed in any order that can accomplish a securing or unsecuring operation. For example, the steps in a securing operation can alternatively be performed in which step  1030  is performed at the same time as or otherwise overlapping with step  1040 . 
   In one possible mode of operation of unfolding or assembling foldable bicycle  10 , as the seat stays  100  of the rear wheel assembly are positioned, as indicated in reference number  1010 , the leading edges  237  of the connector portions  230  of the seat stays  100  impinge upon the plate  110  at or near the abutment surfaces  160  and exert a force upon the plate  110  that acts as a torque expressed about the hinge  150  causing displacement at the respective ends of the displacement members  270 A and  270 B having the abutment surfaces  160 . Thus, in step  1010 , optionally, the plate  110  is displaced by virtue of positioning of the seat stays  100 . In this mode of operation, the displacement members  270 A and  270 B move upwards under the forces exerted by the leading edges  237  of the seat stays  100  while the opposite end of the plate  110  remains pivotally mounted at hinge  150 . In other words, the leading edges  237  slide on the lower edges of  270 A and  270 B, which also are at or near the respective abutment surfaces  160 . This movement pushes the plate  110  upwards at that location. When the leading edges  237  slide past the lower edges of the displacement members  270 A and  270 B as far as possible, the inner surfaces  235  also are then seated in the respective recesses  300  of the mounting rod  240 , as indicated in the exemplary step  1020 . At or close to the end of the movement of the end portions  230  of the seat stays  100  (which include the surfaces  235 ,  237 ), members  270 A and  270 B are free of the leading edges and become free to move back to a resting position as indicated by step  1040 . 
   Although this discussion concerns impingement of surface  237  on the plate  110 , it should be understood that in an alternative mode of operation, the engagement surface  250  of the locking member  170  has not been retracted, such as by pulling on ring  180 . In such a mode of operation the plate  110  is moved by virtue of the surface  237  impinging upon a portion of the engagement surface  250 . 
   Preferably the plate is biased towards the resting position by biasing assembly  140  as well as previously discussed—allowing the plate  110  to rebound downward to its resting position—which will be as far as the mating abutment surfaces  160  and engagement surfaces  165  are structured to permit. In an embodiment in which the engagement surface  250  has been retracted, such as by pulling on the ring  180 , once the lower edge of the plate  110  is clear of the engagement surface  250  of the locking member  170  can return to its resting position, such as the position biased by biasing assembly  290 , whereby it locks the securing apparatus and seat stays from further motion, as indicated in step  1050 . Optionally a biasing assembly is not provided and a user can manually operate the securing apparatus  20  to return the plate to its resting position. In an embodiment in which the engagement surface has not been retracted, it should be understood that a step or rotating the plate  1040  downward can serve to impinge a portion of the engagement surface  250  with edge  237 . In such an embodiment, it is preferred the engagement surface has a curved profile whereby the contact forces urge it outwards, i.e. to rotate the locking member about the pivot axis of pivot assembly  289 . Once the engagement surface  250  is clear of the bottom edge of the end portion of the seat stay  230 , it can then snap back to a securing position by virtue of operation of biasing assembly  290 , or by manual operation, as indicated in step  1050 . 
   Unlocking the securing mechanism and folding a bicycle  10  of the present invention can be accomplished by performing the steps illustrated in  FIG. 12 , in opposite order. In other words, the assembly is unlocked by rotating the pivot member ( 1050 ), until the engagement surface  250  is clear of the plate  110  and seat stays  100 , then pulling up on the plate  110 , i.e. rotating it out of engagement with the surfaces  165  ( 1040 ), then optionally releasing the locking member to return to its resting position as biased by the biasing assembly  290  ( 1030 ), uncoupling the seat stays ( 1020 ), and finally folding the bicycle as desired, such as by folding the rear wheel assembly  90  ( 1010 ) and optionally folding the front wheel assembly  80  and handlebar assembly  70  as desired. 
   Thus, it is seen that a releasable securing apparatus is provided. One skilled in the art will appreciate that the present invention can be practiced by other than the above-described embodiments, which are presented in this description for purposes of illustration and not of limitation. The description and examples set forth in this specification and associated drawings only set forth embodiment(s) of the present invention. The specification and drawings are not intended to limit the exclusionary scope of this patent document. Many designs other than the above-described embodiments will fall within the literal and/or legal scope of the following claims, and the present invention is limited only by the claims that follow. It is noted that various equivalents for the particular embodiments discussed in this description may practice the invention as well.