Patent Application
20240009044
The present invention relates to an automatic braking device configured to prevent unintended rollback of a manually propelled vehicle (such as a wheelchair, in one instance) as an occupant of the vehicle exits or as the vehicle remains unattended and, more particularly, to a vehicle wheel stopper at least reducing and preferably ceasing the backward rotation of the wheel without human control when standard brakes with which such vehicle is equipped have not been activated.
Embodiments of the invention provide an article of manufacture that includes at least an automatic braking device and, in some implementations, a manually-propelled vehicle structurally and operationally reversibly integrated with such automatic device. The automatic breaking device includes at least a housing structure and a brake pad contained in the housing structure. The housing structure has a front housing shell and a back housing shell configured to be reversibly assemblable together to define a space of the housing structure, and identifies a top portion of the housing structure and a bottom opening that is formed between the front housing shell and the back housing shell opposite the top portion. The brake pad defines a plane of the brake pad and includes a head portion of the brake pad and a brake leg that extends from the head portion. The head portion of the brake pad is configured to be reversibly affixed inside the space at the top portion to the housing structure with the brake leg extending throughout the space towards the bottom opening. Notably, and whether the article of manufacture does or does not include a vehicle in combination with the braking device, such article is devoid of a part controlling a movement of the brake pad in a motorized fashion, and/or devoid of a brake rotor, and/or devoid of a component configured to reposition the brake pad along a radius of the wheel of the vehicle after the device has been cooperated with the wheel. Substantially in every implementation, the housing structure may be dimensioned to permit repositioning of the brake leg in the plane of the brake pad between side walls of the housing structure and/or spatially limit said repositioning at at least a portion of a side wall of the side walls of the housing structure; and/or, when corresponding dimensional extents of the front housing shell and the back housing shell are substantially equal to one another, the housing structure may be dimensioned to define in an assembled state a volume substantially enclosed by the front and back housing shells (such that access to such volume is formed through the bottom opening). Alternatively or in addition, and substantially in every implementation, the article of manufacture may be configured to satisfy at least one of the following conditions: a) the head portion of the brake pad is equipped with an opening throughout the head portion and the housing structure contains or is complemented with a shaft or axle that is fitted into and/or through the opening when the brake pad and the housing structure are assembled together; b) this shaft or axle is integrated with a housing shell of the front and back housing shells, c) such opening throughout the head portion of the brake pad is not a substantially cylindrical opening and has an internal surface, while the article of manufacture additionally includes a washer having an outer surface of the washer that is substantially dimensionally complementary to the internal surface of the opening throughout the head portion of the brake pad; d) the internal surface of the opening throughout the head portion of the brake pad is dimensioned to form at least one dihedral angle; e) the washer includes a washer portion containing such outer surface of the washer, and the washer portion is dimensioned to be received within this opening throughout the head portion of the brake pad to substantially prevent mutual rotation between the brake pad and the washer about the axis of this opening when the washer portion is inserted in this opening.
Generally, the active braking device is configured such as to have an end of the brake leg to remain in frictional contact with a wheel of the manually-propelled vehicle (with which the active braking device is configured to be juxtaposed) while not preventing a rotation of the wheel when the wheel is rotated in a forward direction, and/or the braking device is configured to have the brake leg to at least compress such as to change a shape of the brake leg and increase frictional contact between an end of the brake leg and the wheel when the wheel is rotated in a backward direction, and/or the braking device is configured to have the brake leg reversibly flex in the backward direction when a momentum of rotation of the wheel in the backward direction exceeds a threshold value while, at the same time, to have the brake leg flex in the forward direction when a direction of the rotation of the wheel in changed from the backward direction to the forward direction.
Embodiments of the invention additionally provide a method that includes at least the following steps: (i) cooperating an automatic braking device with a wheel of a manually-propelled vehicle such that an outer surface of the brake leg remains in frictional contact with an outer portion of the wheel regardless of whether the wheel is rotated in a forward direction or in a backward direction; (ii) keeping a level of friction between the brake leg and the outer portion of the wheel below a level of static friction by having the brake leg repositioned in the forward direction (when the wheel is rotated in the forward direction); and (iii) necessarily increasing the level of friction by having the brake leg repositioned in the backward direction (when the wheel is rotated in backward direction). Notably, the step of increasing the level of friction may include increasing said level of friction to the level of static friction, thereby substantially preventing a rotation of the wheel in the backward direction (and/or stopping such rotation of the wheel). As is well recognized in related art, static friction is a force that keep an object at rest on a surface (˜the frictional force between two surfaces that re not moving related to each other, opposing motion in an object at rest). Alternatively or in addition, and substantially in every implementation, the method may include a step of reversibly flexing the brake leg in the backward direction while not preventing the wheel from continued rotation in the backward direction (this step being implemented when the wheel is rotated in the backward direction with a momentum exceeding a threshold momentum). Embodiments of the method are implemented in such a fashion as to ensure that an ability of the occupant to operate the manually-propelled vehicle is not obstructed by the automatic braking device; and/or such as to ensure that the ability of the occupant to remove and/or replace an armrest of the wheelchair required for the occupant's rising from and/or egressing the vehicle is not obstructed by the automatic device.
The invention will be more fully understood by referring to the following Detailed Description of Specific Embodiments in conjunction with the Drawings, of which:
Generally, the sizes and relative scales of elements in Drawings may be set to be different from actual ones to appropriately facilitate simplicity, clarity, and understanding of the Drawings. For the same reason, not all elements present in one Drawing may necessarily be shown in another. Drawings are generally not to scale.
Implementations of the idea of the present invention are configured as a braking mechanism that, in operating, automatically (that is, substantially without the intervention from the user) locks at least one (and preferably—each of) large wheels of a wheelchair (and, generally, a manually-propelled vehicle including, for example, a wheeled walker such as rollator) against the relatively modest movement backwards when the wheelchair user or occupant attempts to exit the wheelchair (and, especially, when the wheelchair occupant has forgotten or is incapable of remembering to lock the standard wheelchair brakes to prevent backward movement). The occupant, therefore, can safely move from the wheelchair to his or her bed, another chair, a toilet seat, or a seat in an automobile or other vehicle without having their wheelchair roll away from them, and without the added risk of a subsequent and often injurious fall.
In a preferred implementation of this feature, discussed below embodiment automatic braking system(s) is(are) added to at least one—or, preferably, each—side of the wheelchair or manually propelled vehicle that has a somewhat flexible (generally but optionally elastic) brake pad within it. The brake pad has a surface that, after the system is operably cooperated with the wheelchair, rides in contact with the wheel substantially without hindrance, as long as the wheel is moving and/or rotating forward. As soon as the wheelchair wheel is directed by the occupant to move in reverse, resistance is automatically immediately applied by an end portion of the brake pad to hinder that motion. The applied frictional resistance is more than sufficient to keep an unoccupied wheelchair from rolling backwards, but can be overcome by even modest effort if the wheelchair occupant simply wishes to move backwards while they are still in the wheelchair, by pushing the wheelchair wheel backward as they normally might. As soon as the occupant moves the wheelchair forward again, the flexible brake pad of the automatic braking system is moved (reloads) to its original position and is, therefore, positioned to again prevent the wheelchair from moving backwards again, if unoccupied.
Accordingly, a problem of operation of manually-propelled vehicles manifesting in an unintentional backward motion and/or roll-back of the vehicle (that is caused by an attempt of the user to exit the vehicle while forgetting to apply a standard vehicle brake and that often results in a fall of the user who assumes that the vehicle is still behind him) is solved by providing an automatic braking device which, when cooperated with a wheel of the vehicle, prevents the vehicle from rolling back while at the same time not interfering with intentional movement of the vehicle in either forward or backward direction.
Unless expressly defined otherwise, the term automatic, as used in reference to a device or a process, implies that such device or process works or operated by itself and with no direct human intention or control. The term manually propelled vehicle, as used here, refers to and covers a wheelchair (employed by a user in case of experiencing difficulties with walking due to injury, illness, or disability, for example), a pram, or another vehicle-like contraption propelled by the weight or force of one or more persons skating, sliding or riding on the vehicle or by one or more other persons pulling or pushing the vehicle. A forward direction as used herein is a term defined to denote and refer to a direction of repositioning of the manually propelled vehicle moving forward and/or a direction of rotation of a wheel of such vehicle when the vehicle is moving forward; a backward or reversed direction is a direction opposite to the forward direction.
The numeral 132 identifies a standard braking mechanism with which a conventional standard wheelchair is equipped in related art, and which requires the input of the user of or attendant to the chair 100 to be activated. Such standard mechanism is often configured as a bracket that is, in operation, pushed against the wheel (the tire of the wheel) until it comes into a reversible frictional contact with the wheel to effectively reduce the ability of the wheel to rotate and/or substantially completely lock the wheel until the user lifts the bracket to free the wheel.
Details of the structure of one embodiment of the braking device 124, on the other hand, are presented in
The embodiment 200 of the brake pad is shown to include a brake plate 212 (with rear and front portions 212R, 212F of the brake plate that are interconnected with one another via a head portion (or bridge portion) 216 of the brake plate and that are mutually oriented to define a slit 220 between the portions 212R, 212F). The head or bridge portion 216 is shown to have a throughout aperture or opening 218, through which the fixator 208 (in this case, the through screw or bolt, appropriately cooperated with the corresponding nut and optionally washer, as shown) is passed to affix the brake pad 200 within the dedicated space afforded by the shell 204A prior to sandwiching the pad 200 between the half-shells 204A, 204B and closing the housing 204 with the pad 200 contained inside. As shown, the fixator 208 may be configured as an axle about which the pad 200—while outside of the housing 204—can swing or rotate in the plane of the pad 200 and along which the pad 200 can be repositioned when the housing 204 is not assembled yet. However, the housing shell 204A is dimensioned such that, when the pad 200 already cooperated with the fixator 208 is placed within or at the shell 204A, substantially any movement or motion of the brake pad 200 in the plane of the pad 200 (here, xy-plane) or in a direction transverse to the plane defined by the pad 200 is prevented. For example, the inner portions of the walls 224A, 224B of the housing shell 204A can be dimensioned such as to come substantially in contact with the outermost surfaces 228A, 228B of the brake plate. (In a related implementation, the housing shell 204A may be optionally dimensioned such that the inner portions of the walls 224A, 224B come substantially in contact with the outermost surfaces 228A, 228B of the brake plate while, at the same time, an inner surface 232 of the responding housing shell 204B is brought in contact with the back surface 236 of the pad 200.)
Referring now to
Referring again to
A completed assembly of the embodiment 124 is shown in front view in
Overall, the front and back housing shells 204A, 204B form a space or a volume therebetween dimensioned to accommodate the embodiment of the brake pad and dimensioned such as to permit repositioning of the leg of the brake pad in the plane of the brake pad between side walls of the housing structure and/or spatially limit such repositioning at at least a portion of a side wall of the side walls of the housing structure. When reversibly assembled together with the brake pad secured in-between, the housing shells 204A, 204B define a housing structure that has a top portion and a bottom opening or aperture between the shells opposite the top portion, while the leg of the brake pad extends from the head portion (affixed at the top portion of the housing structure between the housing shells) towards such bottom opening or aperture.
Having the advantage of the above-presented disclosure, the skilled person will now readily appreciate the principle of operation of the above-discussed embodiment of the invention in reference to
As shown in
The skilled person will readily appreciate that an embodiment of the braking mechanism can be appropriately modified and/or simplified without deviating from the idea of the invention. One possible modification is schematically illustrated—in different perspective views—in
The washer 648 (preferably manufactured from resilient material, such as metal, that is different from the elastic material of the brake pad 600) may be additionally employed and secured with a nut. In at least one specific case, the internal walls of the opening 618 throughout the head portion 616 of the pad 600 and the outer surface of the washer 648 may be spatially complementarily dimensioned in a judicious fashion to dimensionally fit and match each other, each defining at least one dihedral angle, as illustrated in
Notably—and considering optionally different vertical (along the y-axis) extents of the housing shells 204A, 204B—this related embodiment of the braking mechanism, when assembled and appropriately cooperated with the arm-rest 104 and/or the partition 116 of the manually-propelled vehicle (by analogy with the assembly illustrated in
In yet another, simpler implementation of the brake pad—see
The skilled artisan can now appreciate that embodiments of the invention provide an article of manufacture that includes at least a braking device and/or a manually-propelled vehicle equipped with such braking device. The braking device includes at least a housing structure (generally reversibly assembled from a front housing shell and a back housing shell) to define a space covered by the housing structure. The housing structure includes a top portion and a bottom opening between the front housing shell and the back housing shell (which bottom opening is opposite the top portion). The braking device includes a brake pad defining a plane of the brake pad and including a head portion of the brake pad and a brake leg extending therefrom. The head portion of the brake pad is configured to be reversibly affixed in the space at the top portion of the housing structure with the brake leg extending throughout the volume towards the bottom opening.
While the idea of the invention is described through the above-described examples of embodiments, it will be understood by those of ordinary skill in the art that modifications to, and variations of, the illustrated embodiments may be made without departing from the inventive concepts disclosed herein. For example, the affixation of the embodiment of the brake pad 200, 600 within the housing 204, 604 does not have to be necessarily facilitated with the use of an axle such as a fastener/fixator 208, 608 but may be, instead, carried out by the appropriate shaping of the head portion 216, 616 and shaping an inner surface of the housing 204, 604 such as to snappingly affix the bridge portion therein. Disclosed aspects, or portions of these aspects, may be combined in ways not listed above. Accordingly, the invention should not be viewed as being limited to the disclosed embodiment(s).
Examples of materials for use in fabrication of the brake pad include rubber and/or some sort of a known elastomeric compound-based material. The housing structure, discussed below, which at least partially encloses and supports the brake pad, is preferably made of material that is strong, lightweight, and inflexible—at least in reference to the material of the brake pad—such as for example plastic, carbon fiber, even aluminum, to name just a few. As the skilled person will now readily appreciate, the ranges of dimensions of embodiments of the invention are chosen to successfully cooperate such embodiments with the chosen type of a manually-propelled vehicle. Using the wheelchair Invacare Tracer EX 2 as an example, the footprint of a side of the housing structure supporting the brake pad is about 3.5 by 4 inches or smaller, while the footprint of the brake pad in implementation discussed in reference to
For the purposes of this disclosure and the appended claims, the expression of the type “element A and/or element B” has the meaning that covers embodiments having element A alone, element B alone, or elements A and B taken together and, as such, is intended to be equivalent to “at least one of element A and element B”.
References throughout this specification to “one embodiment,” “an embodiment,” “a related embodiment,” or similar language mean that a particular feature, structure, or characteristic described in connection with the referred to “embodiment” is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. It is to be understood that no portion of disclosure, taken on its own and in possible connection with a figure, is intended to provide a complete description of all features of the invention. Within this specification, embodiments have been described in a way that enables a clear and concise specification to be written, but it is intended and will be appreciated that embodiments may be variously combined or separated without parting from the scope of the invention. In particular, it will be appreciated that all features described herein are applicable to all aspects of the invention.
When the present disclosure describes features of embodiments of the invention with reference to corresponding drawings (in which like numbers represent the same or similar elements, wherever possible), the depicted structural elements are generally not to scale, and certain components may be enlarged or reduced in size relative to the other components for purposes of emphasis and understanding. It is to be understood that no single drawing is intended to support a complete description of all features of the invention. In other words, a given drawing is generally descriptive of only some, and generally not all, features of the invention. A given drawing and an associated portion of the disclosure containing a description referencing such drawing do not, generally, contain all elements of a particular view or all features that can be presented is this view, at least for purposes of simplifying the given drawing and discussion, and directing the discussion to particular elements that are featured in this drawing. A skilled artisan will recognize that the invention may possibly be practiced without one or more of the specific features, elements, components, structures, details, or characteristics, or with the use of other methods, components, materials, and so forth. Therefore, although a particular detail of an embodiment of the invention may not be necessarily shown in each and every drawing describing such embodiment, the presence of this particular detail in the drawing may be implied unless the context of the description requires otherwise. In other instances, well known structures, details, materials, or operations may be not shown in a given drawing or described in detail to avoid obscuring aspects of an embodiment of the invention that are being discussed. Furthermore, the described single features, structures, or characteristics of the invention may be combined in any suitable manner in one or more further embodiments.
For the purposes of this disclosure and the appended claims, the use of the terms “substantially”, “approximately”, “about” and similar terms in reference to a descriptor of a value, element, property or characteristic at hand is intended to emphasize that the value, element, property, or characteristic referred to, while not necessarily being exactly as stated, would nevertheless be considered, for practical purposes, as stated by a person of skill in the art. These terms, as applied to a specified characteristic or quality descriptor means “mostly”, “mainly”, “considerably”, “by and large”, “essentially”, “to great or significant extent”, “largely but not necessarily wholly the same” such as to reasonably denote language of approximation and describe the specified characteristic or descriptor so that its scope would be understood by a person of ordinary skill in the art. The use of this term in describing a chosen characteristic or concept neither implies nor provides any basis for indefiniteness and for adding a numerical limitation to the specified characteristic or descriptor. As understood by a skilled artisan, the practical deviation of the exact value or characteristic of such value, element, or property from that stated may vary within a range defined by an experimental measurement error that is typical when using a measurement method accepted in the art for such purposes. As an example only, a reference to a vector or line or plane being substantially parallel to a reference line or plane is to be construed as such vector or line extending along a direction or axis that is the same as or very close to that of the reference line or plane (with angular deviations from the reference direction or axis that are considered to be practically typical in the art, for example between zero and fifteen degrees, more preferably between zero and ten degrees, even more preferably between zero and 5 degrees, and most preferably between zero and 2 degrees). A term “substantially flexible”, when used in reference to a housing or structural element providing mechanical support for a contraption in question, generally identifies the structural element the flexibility of which is higher than that of the contraption that such structural element is associated with. As another example, the use of the term “substantially flat” in reference to the specified surface implies that such surface may possess a degree of non-flatness and/or roughness that is sized and expressed as commonly understood by a skilled artisan in the specific situation at hand. For example, the terms “approximately” and about”, when used in reference to a numerical value, represent a range of plus or minus 20% with respect to the specified value, more preferably plus or minus 10%, even more preferably plus or minus 5%, most preferably plus or minus 2%.
The invention as recited in claims appended to this disclosure is intended to be assessed in light of the disclosure as a whole, including features disclosed in prior art to which reference is made.
This US Patent application claims priority from and benefit of the U.S. Provisional Patent Application No. 63/388,026 filed on Jul. 11, 2022, the disclosure of which is incorporated herewith by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63388026 | Jul 2022 | US |
