Joints and connections – Axially split or separable member
Reexamination Certificate
2000-09-08
2001-10-30
Browne, Lynne H. (Department: 3629)
Joints and connections
Axially split or separable member
C074S551100, C403S373000, C403S374100, C403S408100, C403S409100
Reexamination Certificate
active
06309135
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to the field of mechanical connectors and clamps, and more particularly, to a clamp for connecting to an object, such as the steering tube of a bicycle.
BACKGROUND OF THE INVENTION
A number of applications require connection or clamping to an object, such as a tube, rod or shaft, for example. One example of such an application is for clamping to the steering tube of a bicycle.
Bicycles are widely used for transportation and recreation. A typical bicycle includes a rear wheel carried by a frame and a front wheel carried by a fork which, in turn, is rotatably connected to a forward portion of the frame. In particular, a steering tube is connected at its lower end to the fork and extends through a corresponding passageway defined in the forward portion of the frame. An upper portion of the steering tube is connected to a bicycle stem.
The bicycle stem includes a steering tube clamping portion which clamps to the upper end of the steering tube. A body portion extends generally forwardly and at an upward incline from the steering tube clamping portion and terminates at a handlebar clamping portion. The incline is generally upward for mountain biking and downward for road biking, as desired by the rider. Of course, the medial portion of the handlebar is connected to the handlebar clamping portion of the stem. The rider is thus able to steer the front wheel by turning the handlebar.
The stem is important for proper orientation and positioning of the rider relative to the bicycle. In addition, the stem is desirably relatively strong to avoid potentially catastrophic failure, and is also desirably lightweight to reduce the burden on the rider. Mountain or off-road biking can put especially high demands on the strength of the stem. Road bikes may also place high demands in terms of both required strength and being relatively lightweight on the bicycle stem.
The stem also desirably has relatively high torsional stiffness, that is, a resistance to allowing the handlebar to rotate as the rider pushes on one side while lifting on the other. If the torsional stiffness is too low, the rider's energy is more quickly and wastefully depleted in rotating the handlebar.
A widely used type of bicycle stem includes a body portion or tube and a steering tube clamp connected to an end of the body tube. The steering tube clamp is in the form of a split tube with a vertical slot opposite the body tube. One or typically two bolts or other fasteners are used to secure clamp together at the vertical slot. Unfortunately, the clamp and fasteners extend backward toward the rider and may present an object which the rider may strike or bang with his knees, for example, such as during vigorous riding.
Another type of steering tube clamping arrangement attempts to remove the clamp and bolts from protruding backward into the rider's space. This type of stem includes a vertically oriented tubular portion defining a main passageway that receives the upper end of the steering tube. To secure the stem relative to the steering tube a clamp may be positioned within a second passageway that extends transverse to the main passageway and which is in communication with the main passageway. The clamp typically includes two cylindrical halves or clamping members which can be urged together by a single fastener, such as a bolt which extends along an axis defined by the cylindrical halves. More particularly, the cylindrical halves each include corresponding arcuate recesses which when properly aligned will press against an outer circumferential portion of the steering tube upon tightening of the bolt to thus clamp the bicycle stem to the steering tube. Such stems are shown, for example, in U.S. Pat. Nos. 5,687,616 and 5,842,385.
Unfortunately, the transverse clamp for the steering tube has relatively little surface area to contact the steering tube. The outermost ends may define contact points which bite into the steering tube, thus forming dimples in the metal steering tube. Such deformations of the metal steering tube may be undesirable for a number of reasons. For example, the dimples may subsequent fine adjustment, since the clamp will tend to seat into the dimples. In addition, for a composite material steering tube an entirely different type of clamping arrangement may be needed to avoid causing damage in the composite material which may propagate to failure of the steering tube. Such composite steering tubes are often used on high-end road bicycles, for example. Of course, these same shortcomings extend to other similar clamping applications.
SUMMARY OF THE INVENTION
In view of the foregoing background, it is therefore an object of the invention to provide a clamp which securely engages an object without damaging the object.
This and other objects, features and advantages in accordance with the present invention are provided by a clamp comprising a clamping portion having a tubular shape defining an object receiving passageway therethrough, and a clamp receiving passageway transverse to the object receiving passageway and in communication therewith. An object clamp is positioned in the clamp receiving passageway. The object clamp may include a pair of cooperating clamp members aligned in side-by-side relation and comprising respective portions defining an imaginary cylinder and a recess therein for the object. Each clamp member may also have at least one fastener receiving passageway therein offset a predetermined distance from an axis defined by the imaginary cylinder.
The object clamp may also include at least one fastener extending between corresponding fastener receiving passageways of the pair of clamp members for urging the clamp members together to engage the object. The fastener receiving passageways may be offset the predetermined distance from the axis of the imaginary cylinder in a direction away from the recess. The positioning of the fastener receiving passageways, and, hence the one or more fasteners, in the offset relation from the axis of the imaginary cylinder allows the clamp to be more effective and rugged. For example, a greater extent of the object can be engaged.
In some embodiments, the at least one fastener comprises a plurality of fasteners. For example, the fasteners may comprise first and second bolts, each having an enlarged head and a threaded shaft extending outwardly therefrom. These first and second bolts may be positioned to extend in opposite directions. In other embodiments, only a single fastener may be used. In yet other embodiments, one of the clamp members may be integrally formed in a wall portion of the object clamping portion, while the other clamp member is movable.
In accordance with another advantageous feature of the invention, the fastener receiving passageways may also be canted at a predetermined angle from parallel to the axis of the imaginary cylinder. This may allow the fasteners to be tightened with less likelihood of binding as outer portions of the clamp members engage the object and tend to rotate.
In accordance with another advantageous feature of the present invention, the recess for the object may extend for greater than a predetermined angle, such as greater than about 90, 120 or 180 degrees, for example. This also provides greater contact between the clamp members and the object which, in turn, provides for greater holding power and a reduced likelihood of damaging the object.
The pair of clamp members may each have a same shape which simplifies manufacturing, among other advantages. Each clamp member may also comprise an end having a circular shape, or a truncated circular shape.
A number of the advantageous features of the invention may be used independently or in combination. For example, the multiple fasteners may be used with or without the offset. The canting of the angle of the fastener receiving passageways and at least one fastener may also be used alone, or in combination with other features. The provision of the recess to extend greater than a predetermined angle, can also be used alone
McJunkin Mark P.
Thomson Brian
Thomson Loronzo H.
Allen, Doppelt, Milbrath & Gilchrist, P.A.
Browne Lynne H.
Dunwoody Aaron
L.H. Thomson Company, INC.
LandOfFree
Object clamp including clamp members and associated methods does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Object clamp including clamp members and associated methods, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Object clamp including clamp members and associated methods will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2583879