Patent Publication Number: US-2004050202-A1

Title: Adjustable and foldable stem and bearings for wheeled vehicles

Description:
I. BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] This invention relates to a bicycle stem that can be raised and lowered to adjust the handle bar height and rotated 90 degrees and then folded down so that the handle bar is close to and parallel to the frame of the bicycle for storage. The stem works simply and safely with threaded or threadless steerer tubes using a minimum of materials and parts which are basically standard to the industry.  
       [0003] 2. Prior Art  
       [0004] Bicycles and other wheeled vehicles are often only used occasionally and stored frequently. Yet, due to the laterally protruding handlebars, storage is not particularly convenient. To date, there have been no successful foldable handlebars to alleviate this problem. In addition, consumers are demanding more comfortable bicycles with highly adjustable handlebar positions. In recent years, a large number of adjustable stems have entered into the marketplace. These stems are, for the most part, quite heavy and only adjustable using a tool. In the prior art, there have been no stems whose height is adjustable by hand, that fold-down or that are safe, strong and not too heavy. A great number of stems have focused on being light and strong with U.S. Pat. No. 5,095,770 representative of those proposals but, all are very limited in use by not being adjustable in height by hand, and do not even consider a storage fold-down feature. U.S. Pat. Nos. 5,517,878, 5,540,457, 5,588,336, 5,687,616, 5,680,798 and 5,865,069 show stems that have become progressively heavier and more complicated without offering any adjustability, fold-down, or other meritorious features. U.S. Pat. Nos. 5,737,967 and 5,727,427 with partially folding stems, address the question of storability. U.S. Pat. No. 5,737,967 has the handle bars fold in half and back. These are held by a heavy non-adjustable stem. U.S. Pat. No. 5,727,427 rotates the handle bars 90 degrees to a vertical position in a questionable manner.  
       [0005] The techniques for producing a fully folding stem have in the past been limited to employing a single fixed skewed exterior hinge which in the folding process carried the handle bars through both a 90 degree turn and a drop-down of 90 degrees so that they end up parallel to and close to the frame of the bicycle. In some cases in order to end up in this same parallel position, the stem was rotated up and then down through 270 degrees which achieved the same results.  
       [0006] In all cases, the fundamental principle was that by positioning the hinge in one fixed skewed position, the folding process could be done with a single motion. Although this seems a simpler concept than dividing the folding motion into two parts as done in accordance with this invention, it relies on concept which weakens the stem in the rideable position. That is, a hinge becomes a structural component of the stem when the vehicle is being ridden and this weakens the stem. No matter how well the hinge is made, it allows motion between the connected parts which translates into unwanted motion in the handlebar during riding and weakens the performance of the bicycle. In addition, when the hinge is skewed to one side it creates an unbalanced fastening situation. Finally, when a single rotation of the handle bars is up, back over, and down to reach the folded position, the length of the brake and the derailleur cables must be extra long to handle this extended travel. U.S. Pat. Nos. 5,269,550 and 5,440,948 with their rear hinges show all these defects, and require a tool to operate.  
       [0007] None of the prior art incorporates methods that allow for user error. In many cases, after folding, the handlebar and stem assembly may appear to be ready to be ridden but in fact is not locked into place. Consequently, there is a serious safety issue in these prior art mechanisms.  
       II. SUMMARY OF INVENTION  
       [0008] To overcome the above-noted defects in the prior art, this invention uses a very simple, exterior mounted locking means on the extended threaded or threadless steerer tube. It keeps the interior of the steerer tube clear, and employs an interior, hand-adjustable, full range height adjusted stem and handle bar. The invention uses the extended steerer tube for strength and does not use the pivot hinge as a structural member during riding by placing the folding hinge inside or as part of a non-stressed outside position for safety. The invention is accomplished with a minimum of materials, using those that are standard with the industry. Implementation of the invention is extremely easy to use the very first time—simply unlock by hand, lift, turn, and fold down, Finally the invention works on standard large or small wheel folding or non-folding bicycles.  
       [0009] It is the objective of this invention to define a safe, adjustable, folding stem for a bicycle, a folding bicycle, a motor bicycle, or other wheeled vehicle. This invention comprises a stem which can be adjusted in height without the use of tools, and which can be easily folded down and out of the way for storage. The folding process is accomplished simply by unlocking a quick release, lifting the stem, rotating it approximately 90 degrees, and folding it downward. A frame mounted bracket could be included to hold them handlebar in the folded position.  
       [0010] The invention employs a stem section holding the handlebars at one end and a pivoted and hinged mechanism at the other end which is restrained from pulling out or off the steerer tube. This stem section is able to rotate 90 degrees and in addition, drop down 90 or more degrees so that the handle bars in the folded position are set close to and approximately parallel to the frame of the bicycle.  
       [0011] While performing the fold-down feature the handle bars and interior stem are adjustable by hand for different riding heights. Both interior and exterior hinges include a safety feature against lateral turns with their grooved construction, and a safety feature against folding down during riding by using the interior and exterior surface of the extended steerer tube to prevent the hinging motion, meanwhile remaining light in construction and easy to build.  
       [0012] Using the interior hinge, the steerer tube is fixed onto the stem using a standard slotted clamping device with a quick-release. This clamping collar is bolted to the steerer tube or for threaded steerer tubes, is threaded, then bolted on. Because this clamping collar has protrusions that fit into the stem&#39;s continuous slots, it permits the stem to be raised and lowered while always keeping its alignment. This allows the rider to steer the bicycle even if he or she forgets to lock the quick release clamping device. When the stem is pulled all the way up where the protrusions come out of the slots, the stem can be rotated. At this point the hinge is outside the headset and the bottom section of the hinged stem hits the protrusions forcing it to remain inside the steerer tube.  
       [0013] The means of hinging can be as flexible as a bungee cord or rigid using pinned metal construction. The final positioning of the handle bars is determined when using interior metal hinges by: (a) the length of the vertical and forward-thrust sections of the stem; (b) the basic alignment offset between hinge and the line of the bicycle; (c) the amount of skewing to the side of the hinge; and (d) the angle of rotation before folding down and the amount of fold-down. The handlebars may end up on either side of the vehicle at a wide range of angles. All these are adjusted for folding, non-folding, large wheel or small wheel bicycles. Minor adjustments are made for when a threaded or threadless steerer tube is used, but in general, the threaded construction has a smaller and lighter locking nut and washer than the three-part locking necessary for the threadless construction.  
       [0014] When the rotating quill device is used, the interior bolt, as in a standard quill is tightened and draws the sloping surfaces against one another jamming the quill section against the inside of the steerer tube, thus locking the headset. To fold this version, the sloping (approximately 45 degrees) surfaces rotate relative to one another forming approximately a 90 degree fold. 
     
    
    
     IV. BRIEF DESCRIPTION OF THE DRAWING  
     [0015]FIG. 1 is a perspective view with a pulled-up and then folded steering assembly using a threadless steerer tube;  
     [0016]FIG. 2 is a bottom view section through the hinge area;  
     [0017]FIG. 3 a  is a front view of the hinge area;  
     [0018]FIG. 3 b  is a front view of a skewed hinge;  
     [0019]FIG. 3 c  is a front view of the hinge area with a elastic cord;  
     [0020]FIG. 4 a  is a top view of the top collar showing the hinge mechanism;  
     [0021]FIG. 4 b  is a side view section through a threadless steerer tube with a headset quick release collar with the stem not illustrated;  
     [0022]FIG. 4 c  is a view of the tightening flange for a threadless steerer tube;  
     [0023]FIG. 4 d  is a view of the headset threaded flange for a threadless steerer tube;  
     [0024]FIG. 4 e  is a side view section through the threaded steerer tube without the stem;  
     [0025]FIG. 4 f  is a view of one embodiment of the threaded top quick release clamping collar;  
     [0026]FIG. 4 g  is a view of the headset top nut set with a gap between it and the top quick release clamping collar for threaded steerer tube;  
     [0027]FIG. 4 h  is a view of the threaded steerer tube standard headset washer;  
     [0028]FIG. 5 a  is a side view section of the angled headset showing the folded stem beyond parallel to the bicycle;  
     [0029]FIG. 5 b  is a top view of the angled headset showing the folded stem beyond parallel to the bicycle;  
     [0030]FIG. 6 a  is a side view of the front end of a bicycle showing the folding stem raised out of the headset;  
     [0031]FIG. 6 b  is a side view showing the raised folding stem turned 90 degrees;  
     [0032]FIG. 6 c  is a side view showing the folding stem folded down parallel to the bicycle;  
     [0033]FIG. 6 d  is a side view showing the  22  degree offset-hinge folding stem folded down parallel to the bicycle;  
     [0034]FIG. 6 e  is a side view showing the offset-hinge folding stem folded down parallel to a center fold folding bicycle;  
     [0035]FIG. 6 f  is a side view showing the offset-hinge folding stem with a seat tube fold on a folding bicycle;  
     [0036]FIG. 7 a  is a side view section of a composite ride and fold position illustration of a threadless steerer assembly with a stem quick release surround;  
     [0037]FIG. 7 b  is a partial front view of FIG. 7 a;    
     [0038]FIG. 8 a  is a side view section showing the folded position of a threadless steerer tube with an exterior hinge,  
     [0039]FIG. 8 b  is a partial front view of FIG. 8 a  in the riding position;  
     [0040]FIG. 9 a  is a side view showing the folded position of a threadless steerer tube with an exterior hinge and star nut;  
     [0041]FIG. 9 b  is a front view of FIG. 9 a;    
     [0042]FIG. 10 a  is a front view of a rotating quill interior hinge design in the folded position with the handle bars parallel to the bicycle;  
     [0043]FIG. 10 b  is a front view of a rotating quill interior hinge design in the unfolded, raised position with the handle bars rotated to the opposite side;  
     [0044]FIG. 10 c  is a side view of a rotating quill interior hinge design in the riding position with the entire quill and handle bars turned to the front, in the riding position; and  
     [0045]FIG. 11 is a side view of a rotating quill design with the hinge located below the quill. 
    
    
     V. DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0046] In all of the embodiments, the parts which raise and lower with the stem are designated with odd numbers and the fixed stem parts and bicycle connecting parts are designated with even numbers. In FIG. 1, the vehicle head tube  10  holds the standard top and bottom bearings  8  and  12  of a standard threadless headset. The top clamping collar  26  is bolted to the steerer tube. Below the clamping collar, as illustrated in FIG. 4 b  but shown in FIG. 1, is the smooth interior-threaded exterior flange  22  that has a tooth projection  24  which fits up into the quick release slot of the upper collar. Threaded on this flange is an adjuster-tightening flange  18  with wrench slots  20  which tightens down onto the slotted clamp  14  with its Allen key bolt  16 . This pressure adjuster system is clearly shown in FIG. 4 b  which illustrates the quick release  28 , slot  30 , and nut  32  on the slotted collar  26  secured to the steerer tube  6  with the set screw  36 .  
     [0047] The clamping collar, as shown in FIG. 4 a,  has projection  38  which guides the vertical section of the stem. In FIG. 1, the top and bottom vehicle tubes  40  and  42  complete the fixed elements.  
     [0048]FIG. 1 along with FIGS. 4 a,    4   b,    4   c  and  4   d  illustrate an adjustable folding stem used with a standard threadless steerer tube and headset. FIGS. 4 e,    4   f,    4   g  and  4   h  show a threaded steerer tube setup and this head set construction can be substituted for  4   a,    4   b,    4   c  and  4   d  using the same stem as shown in FIG. 1. FIG. 4 e  shows the steerer tube threaded all the way down to the top race  108  which is wedge fit into the outer head tube  10 . The ball bearings  106  ride between the race  108  and the upper bearing cup  104  which is threaded onto the steerer tube  6 . The standard head set washer  92  shown in FIG. 4 h  with inward set tooth  94  slides down on the bearing cup  104 , its tooth  94  fitting in the groove  96  below the slot  34  which as the arrow indicates belongs under the collar quick release slot shown on FIG. 4 f.    
     [0049]FIG. 4 g  shows the standard headset nut  90  which tightens down onto to the bearing construction but does not touch the top collar  98  shown in FIG. 4 f.  This collar  98  is threaded onto the top thread portion  100  of the steerer tube and is correctly secured so the projections  38  are perpendicular to the bicycle with the small bolt  36  coming through the hole  102 .  
     [0050] In FIG. 1 the stem is shown pulled all the way up ready to turn and fold. The bottom plug  1  of the lower part of the stem cannot be raised higher because of the collar  26  projections  38 . When the lower tooth of the hinge  3  is rotated it does not hit the projections  38 . The lower tooth  3  is pinned to the upper teeth  7  with the pin  5 . The vertical stem  9  can be of varying lengths depending on the range of adjustability desired and whether it is used with large or small wheel bicycles. The indentations  11  house the collar projections  38  and keep the stem from rotating in case binder  28  is not locked during riding. The standard stem forward thrust member  13  holds the standard clamp  15  and handle bars  17 .  
     [0051]FIG. 2 is a bottom sectional view looking up showing the 22 degree offset between the hinge direction and the forward-thrust stem section. Variations of the 22 degree angle change the folded position of the handlebar. If the 22 degrees is reduced to zero, the handlebars will end up folded perpendicular to the steerer tube. A negative angle can also be used to position the folded handlebars on the opposite side of the bicycle. FIG. 3 a  is a front view of the hinge construction showing the skewed stem slots  11 . FIG. 3 b  is a front view of the hinge construction showing the variation of skewing the hinge to change the position of the folded members. FIG. 3 c  shows the introduction of an elastic chord  35  to replace the hinge in a less expensive model.  
     [0052]FIG. 5 a  is a side view using the threadless head set and stem construction of FIGS. 4 a,    4   b,    4   c  and  4   d  and with the stem and handle bars in a folded position parallel to the bicycle. As shown in FIG. 5 a  the 22 degree skewed angle of hinge with vertical stem section  9  in a horizontal position causes the throw section of the stem  13  to drop vertically and the handle bars to be approximately parallel to the ground as shown also in FIG. 6 d.  FIG. 5 b  is a top view of FIG. 5 a.    
     [0053] The diagrams of FIG. 6 a  through  6   f  show the handle bar positioning as it relates to folding and non-folding bicycles. FIG. 6 a  is the diagram as shown in FIG. 1 with the handle bar and stem pulled all the way up. FIG. 6 b  shows the handle bar rotated 90 degrees. FIG. 6 c  shows the handle bar folded down and perpendicular to the head set as if the offset angle were zero. FIG. 6 d  shows the handle bar folded down and parallel to the ground as if the offset angle were 22 degrees. FIG. 6 e  shows the same fold but used with a center folding bicycle with the front and back wheels lined up, and FIG. 6 f  shows the same with a seat tube folding bicycle with the front wheel removed. The standard front frame construction is made up of the top tube  40 , down tube  42 , and seat tube  54  with crank  60  and chain wheel  62 . The center fold bicycle shown in FIG. 6 e  has a center bar  44 , a center member  50 , a center pivot  52 , and a seat tube restraint plate  46  with locking bolt  48 . The back frame has seat stay  70  and chain stay  72  holding rear axle  74  and rear wheel  76 . In FIG. 6 f,  the seat tube fold has top and bottom seat tube collars  56  and  58 .  
     [0054]FIG. 7 illustrates a second embodiment which employs an extended steerer tube and an internal hinge, but does not slot the upper steerer tube for clamping on to the stem. FIG. 7 a  shows a standard threadless steerer tube with a threaded slotted locking nut  22  tightened onto the steerer tube and threaded onto a second slotted locking nut  18  which applies pressure on the standard threadless headset bearing member  12 . As in the other configurations illustrated in FIGS.  1  to  6 , the steerer tube extends beyond the bearing for locking and securing the folding stem. In the case of FIG. 7 a,  however, the locking quick release rides with the vertical folding stem section  21  with slotted area  19  which wraps around and is squeezed onto the steerer tube  6 .  
     [0055] A wedge  33  is pinned to the steerer tube and the member  21  has a wedge slot that fits onto this during riding to prevent rotation in case the quick release is not tightened during riding. This wedge and slot are clearly shown in the front view in FIG. 7 b  but could be replaced with the channel  11  and protrusions  38  of FIG. 1. FIGS. 7 a  and  7   b  show a folding, non-adjustable stem. However, if the steerer tube was threaded on the inside and an additional inside threaded tube were added, this tube could house the smaller diameter vertical stem and telescope up to adjust the handle bar height.  
     [0056]FIG. 8 shows a third embodiment which employs the extended steerer tube found on other embodiments but in this case the top is not slotted and there is no internal hinge. FIG. 8 a  is a front view of a folded threadless steerer tube with an exterior collared vertical upper stem section  19  and lower section  27  raised and lowered onto the steerer tube and hinged at  25 , stopped from pulling out with pin  29  and having a handle  31 . As shown in FIG. 7 a,  a locking and tightening threaded nut and flange apply pressure on the bearing set. FIG. 8 b  shows the locked riding position of FIG. 8 a.  FIG. 9 a  is a threadless steerer tube with the same folding system but with a star-nut head set construction in lieu of the standard flange and nut of FIG. 7 a.  FIG. 9 b  illustrates the riding position of this embodiment.  
     [0057]FIG. 10 shows a fourth embodiment which employs the internal hinge concept of other embodiments, however, it uses a quill type method for locking and it does not use the extended steerer tube used in all other embodiments. FIG. 10 a  shows the handle bar in the folded position parallel to the bicycle. The upper section of quill stem  9  has the continuous anti-rotation slots  11  on each side and allen key or quick release  37  tightens the hinge quill bolt  39 , turning in the threaded section  41 . This is attached to the upper hinge section  7  with pins to lower section  3  which is part of the bolt  43  which is screwed in to the lower section of the quill  45  which is partially slotted  11  as shown. When folding the stem, the lower quill section  45  is being pulled up it is stopped by a protrusion collar  49  which has been screwed onto and pinned to the standard top threaded nut  22  after it has been set. These protrusions and slots are an alignment guide for the head set and are optional.  
     [0058]FIG. 10 b  shows the handle bar rotated 180° to the opposite side. Since bolt  39  rotates freely with respect to the upper quill section  9 , it and the hinge and the lower section  43  can remain unturned always aligned with the quill 45° sloping surfaces. The next step is the entire quill stem is turned 90° to face front. FIG. 10 c  shows the side view with bolt  39  tightened down in the threading  41  activating the sliding quill action and securing the handle bars in the standard manner.  
     [0059]FIG. 11 shows the entire hinge mechanism set below and attached to the bottom section  45 . Again the protrusions and slots would be optional.  
     [0060] It will be appreciated that modifications of this invention may be practiced without departing from the scope of this invention. For example, the quick release used in the embodiments could be replaced by a bolt or wing nut or other tightening technique.