Patent Application
20220340188
Wheels are used on various apparatuses to provide movement and portability. A wheel may be locked to provide stability and may be unlocked to allow movement.
Lockable wheels may be used to conveniently move and position computing equipment, such as desktop or gaming computer tower cases, which may be heavy and too cumbersome to move comfortably. For example, a computing device may be positioned at a location that is out of the way, such as under a desk, between pieces of furniture, adjacent a wall, etc., only to be brought out occasionally when access to the case is desired. Lockable wheels allow long-term stowage of computing devices in a way that preserves convenient access when desired. Moreover, lockable wheels reduce or eliminate the need to lift a computing device, which can allow for greater accessibility by a wide variety of users.
Wheel locking and unlocking is often achieved with a brake mechanism that includes several moving parts. Such mechanisms may be quite complex and have multiple points of failure. When multiple wheels are to be locked and unlocked, the user has to actuate each wheel's brake mechanism individually or additional linkage components are used to link the individual brake mechanisms. Such systems tend to be complex, cumbersome to use, and unreliable.
This disclosure provides examples of automatic locking wheels for a chassis or case of a computing device or similar container, in which a wheel normally locks by way of a coaxial locking body with flat surface (e.g., an octagonal plate) that abuts a flat surface of the chassis. When the case is depressed towards a surface on which the case is disposed, e.g., a person presses down on the case, the wheel deflects a plate spring or other deflectable member, which disengages the flat surfaces and allows the wheel to roll. The plate spring serves to both capture the wheel and engage/release the locking body. This mechanism has reduced complexity and fewer points of potential failure. In addition, multiple of such automatic locking wheels provided to the same chassis or container may be actuated simultaneously without additional linkage components.
The wheel apparatus 100 includes a base 102 that provides a first locking surface 104. The base 102 may be part of the chassis of a computing device, such as a bottom wall, or a wall or panel that is closest to or facing a surface on which the computing device is resting or disposed. The first locking surface 104 may be a flat surface or other feature that acts as a stop.
The wheel apparatus 100 further includes a wheel 106, a locking body 108, and a deflectable member, such as a plate spring 110. As discussed below, the plate spring 110 secures the wheel 106 to the base 102 and further provides for locking and unlocking of the wheel 106 with respect to the base 102 by the locking body 108.
The wheel 106 is generally cylindrical and includes a cylindrical central axle 112 about which the wheel 106 rotates. The wheel 106 rotates in unison with the axle 112, which may be rotatably held by the plate spring 110. The wheel 106 is of larger diameter than the axle 112 and protrudes from an opening 114, such as an opening in the bottom of the chassis or other object that is carried by the wheel apparatus 100, which in this example is an opening in the base 102. The wheel 106 may be formed monolithically with the axle 112 or may be a separate part that is attached to the axle 112.
The locking body 108 is disposed at the axle 112 of the wheel 106 and rotates in unison with the axle 112 and the wheel 106. The locking body 108 may be positioned at an end of the axle 112. The locking body 108 may be a plate or have a plate shape. The locking body 108 may be formed monolithically with the axle 112 or may be a separate part that is attached to the axle 112. Any number of locking bodies 108 may be provided. In the example depicted, two locking bodies 108 are provided, one at each distal end of the axle 112 on opposite sides of the wheel 106.
In this example, the wheel 106, axle 112, and locking body 108 are coaxial and rotate in unison.
The locking body 108 includes a second locking surface 116 to engage the first locking surface 104 of the base 102 to lock the wheel 106 against rotation. The first and second locking surfaces 104, 116 may be brought into mutual abutment or contact that restricts free rotation of the second locking surface 116 and thus restricts free rotation of the axle 112 and wheel 106. In the example depicted, the second locking surface 116 is a flat surface that abuts the flat first locking surface 104 to stop rotation of the axle 112 and wheel 106. In other examples, the first and second locking surfaces 104, 116 are provided with other complementary shapes, such as non-circular shapes, that provide locking contact or engagement.
The locking body 108 may include any suitable number of second locking surfaces 116 in any suitable arrangement that allows each second locking surface 116 to engage the first locking surface 104 of the base 102. The locking body 108 may be a plate-shaped body with a polygonal perimeter that provides the second locking surfaces 116. In the example depicted, eight second locking surfaces 116 are provided as the outside surfaces of a regular octagonal locking body 108.
The first and second locking surfaces 104, 116 are selectively engageable to lock and release the wheel 106 by way of the plate spring 110.
The plate spring 110 captures the axle 112 in a rotatable manner to allow the axle 112 and wheel 106 to rotate. In this example, the plate spring 110 includes an arcuate portion 118 complementary to the round shape of the axle 112. The arcuate portion 118 receives the round portion of the axle 112. The plate spring 110 may have ends 120, 122 affixed to the base 102. The arcuate portion may be positioned about midway between the ends 120, 122. The plate spring 110 may be considered a support bracket with ends 120, 122 attached to the base 102.
The plate spring 110 may further include bends 124, 126 to offset the arcuate portion 118 from the base 102 to provide space between the arcuate portion 118 and the base 102 to capture the axle 112.
The plate spring 110 may include a deflectable portion 128 between the ends 120, 122. The deflectable portion 128 may include a flat elongated portion, which may be made of thin metal or stiff plastic to provide a resilient spring force, which may result from elastic deformation of the deflectable portion 128 under external force and return to its initial shape after removal of external force.
The plate spring 110 may include a slot 130 to accommodate the wheel 106. The slot 130 may be bounded by two deflectable portions 128 on either side. The axle 112 may be captured by the plate spring 110 at two opposing sides of the slot 130, for example, by two arcuate or round portions 118.
The wheel 106, axle 112, and locking body 108 may be captured between the plate spring 110 and the base 102 by the constraints of the locking body 108 abutting the base 102 and the axle 112 abutting the arcuate portion 118 of the plate spring 110.
The wheel 106, axle 112, locking body 108, and plate spring 110 may be considered a lockable wheel assembly that is attachable to a base 102, such as a wall or other structure of a chassis or container, by the ends 120, 122 of the plate spring 110, which acts as a deflectable support bracket to carry the weight of chassis or container.
The plate spring 110 urges the second locking surface 116 of the locking body 108 against the first locking surface 104 of the base 102 to lock the wheel 106. Under application of an external force, the plate spring 110 deflects, which separates the second locking surface 116 of the locking body 108 from the first locking surface 104 of the base 102 to allow the wheel 106 to roll.
The number of second locking surfaces 116 may be selected as different from the examples discussed herein. The second locking surfaces 116 are arranged to be angularly separated from one another such that, at any given angular position of the wheel 106, the external force can be removed and there will be a second locking surface 116 sufficiently aligned with the first locking surface 104 to be able to lock the wheel 106. That is, at any given rotation of the locking body 108, a corner or edge that terminates a second locking surface 116 will be able to contact the first locking surface 104 to impart rotation to the locking body 108 to bring the second locking surface 116 into locking contact with the first locking surface 104. The larger the number of second locking surfaces, the higher the fidelity or precision with locking the chassis in its current location after movement.
In
As shown in
When the applied external force, FA, is removed, the apparatus 100 automatically returns to the locked state shown in
The spring force provided by the plate spring 110 may be selected to support an expected range of loading or weight, FW, while keeping the wheel locked, and further to release the brake under a desired range of applied force, FA. A suitable spring force may be selected by the sizing, thickness, and/or material of the plate spring 110, as well as the shape of the deflectable portion 128 and bends 124, 126.
The axle 112 includes a round surface 402 to provide for rotation of the wheel assembly 400 and a flat surface 116 to provide for locking of the wheel assembly 400. The round surface 402 is sized to nest within an arcuate portion 118 (
With reference to
In other examples, any suitable shape of locking body with multiple locking surfaces may be provided. It should be recognized that fewer locking surfaces may provide for stronger locking effect, by way of larger locking surfaces, with the tradeoff of fewer angular increments at which to stop.
In view of the above it should be apparent that a lockable wheel apparatus may include a deflectable member that urges a locking body into contact with a stop, such as an inside surface of a container or chassis to which the lockable wheel apparatus is provided. A wheel may thus be normally locked. When an external force is provided, such as by a person's hand, the deflectable member deflects and separates the locking body from the stop to allow the wheel to rotate and the container or chassis to be rolled. Release of the external force locks the wheel again irrespective of its rotational position. The apparatus has reduced complexity by way of the deflectable member providing both support and locking/release action. In addition, multiple of such lockable wheel apparatuses may be simultaneously released and then relocked with a simple press-and-release action and without the need for linking mechanism.
It should be recognized that features and aspects of the various examples provided above can be combined into further examples that also fall within the scope of the present disclosure. In addition, the figures are not to scale and may have size and shape exaggerated for illustrative purposes.
