Device for wheelchairs and wheelchairs comprising such device

Abstract

The present invention relates to a device for mounting an auxiliary means to a wheelchair is disclosed. The device comprises a chassis, fastening means for releasably securing the chassis to the wheelchair, and an auxiliary means, such as a docking fixture, auxiliary drive unit, battery pack, or shelf. The fastening means includes a set of guide brackets each having a guide recess, a guide rod mounted to the chassis, and a locking mechanism partly arranged on the chassis and the brackets. The guide recess comprises a linear guide slot section with an open end and a closed end, enabling the guide rod to slide or roll into position. The device may be operable with one hand and without tools. A method for mounting the device, a wheelchair incorporating the device, and a retrofit kit for installing the device on existing wheelchairs are also disclosed.

Description

[0001] Device for wheelchairs and wheelchairs comprising such device

[0002] Technical field of the invention

[0003] The present invention relates to auxiliary means for wheelchairs, e.g., to means adapted to secure the wheelchair into a transport vehicle.

[0004] Background of the invention

[0005] The welfare and safety of persons being transported in wheelchairs is of ever-increasing concern, and many jurisdictions have enacted stringent safety requirements for devices to secure the wheelchair into the transport vehicle and the occupant into the wheelchair. When preparing for transportation, users may want to attach or detach auxiliary means to or from their wheelchairs, or even substitute one auxiliary means with another.

[0006] CN111374839 (A) discloses a vehicle-mounted fixing device for a wheel type auxiliary tool. The device is used for fixing the wheel type auxiliary tool in a designated area and comprises an auxiliary tool end assembly and a fixing end assembly. The auxiliary tool end assembly is detachably installed at the bottom of the wheel type auxiliary tool. The fixing end assembly is fixed in the designated area. By simply pushing the wheel-shaped assistive device to move towards the fixing end assembly, the auxiliary tool end assembly can utilize a vertical clamping opening and a horizontal clamping opening to buckle a horizontal stop rod and a vertical stop rod of the fixing end assembly respectively, and meanwhile the fixing end assembly also utilizes a slot to fix a clamping hook of the auxiliary tool end assembly, so that the purpose of quickly fixing the wheel type auxiliary tool is achieved. The clamping hook of the auxiliary tool end assembly can be separated from the slot through simple operation so as to move the wheel type auxiliary tool.

[0007] US4754946 (A) discloses apparatus for anchoring a wheelchair to the floor of a vehicle while allowing 360 DEG manual rotation of the wheelchair comprising a support bracket connected to the underside of a wheelchair, a vertical shaft extending downward from the bracket and a single locking assembly, connected to the floor of the vehicle, positioned to engage the vertical shaft.

[0008] Auxiliary means, such as a first female or male docking fixture, an auxiliary drive unit, parts of an auxiliary drive unit, a battery pack, or a shelf, are often essential components that add functionality and versatility to a wheelchair. However, the ability to easily and quickly attach or detach these components is equally crucial for several reasons.

[0009] In emergency situations, a wheelchair user may need to quickly reduce the weight or size of their wheelchair to navigate through narrow spaces, avoid obstacles, or be more easily transported by caregivers or emergency personnel. For instance, detaching a heavy battery pack or an auxiliary drive unit can significantly reduce the overall weight of the wheelchair, making it more manageable and less cumbersome. This can be particularly important during evacuations or in scenarios where the user needs to move rapidly.

[0010] Additionally, the ability to detach these components using one hand is particularly vital for users who may have limited mobility or strength in one arm. Many wheelchair users rely heavily on one hand for most of their daily tasks, and a design that requires both hands to operate can severely limit their independence. By ensuring that auxiliary means can be detached with a single hand, designers and manufacturers can greatly enhance the usability and accessibility of the wheelchair. This consideration is essential for fostering a sense of autonomy and reducing the dependence on others for assistance.

[0011] Furthermore, convenience in daily life plays a significant role. For instance, a user may need to quickly remove a shelf or a docking fixture to fit the wheelchair into a car or to store it in a confined space. The ease of detachment can make transitions smoother and less time-consuming, allowing users to maintain an active and engaged lifestyle without being hindered by cumbersome equipment.

[0012] Hence, there is a need for a device for auxiliary means securement to or beneath a wheelchair that solves the above-mentioned problems.

[0013] Summary of the invention

[0014] The present invention relates to a device for mounting auxiliary means to a wheelchair, and in particular to a chassis and fastening system that allows secure, ergonomic, and optionally tool-free engagement of auxiliary devices such as docking fixtures, battery packs, drive units, or shelves to a wheelchair frame. The invention provides solutions that improve ease of use, safety during transport, modularity, and accessibility for users with limited dexterity or mobility.

[0015] A significant advantage of the invention lies in its use of guide brackets and a guide rod to enable controlled, guided insertion of the device beneath or adjacent to the wheelchair. The guide recesses, optionally comprising a linear slot and cam section, help position the chassis precisely and may also provide haptic or tactile feedback. A locking mechanism, including sleeve units and locking brackets, enables releasable engagement without requiring tools. The system is designed to be mountable with minimal user effort, and may be configured for one-handed operation, making it suitable for users with reduced upper-body functionality.

[0016] The device may be integrated directly into a wheelchair during manufacture or provided as part of a retrofit kit for existing wheelchair models. The system is modular and can be adapted to accommodate various auxiliary devices, including those requiring electrical interfacing. The chassis may be formed in a tubular or U-shaped configuration to permit access to adjustment points and facilitate maintenance.

[0017] In a first aspect, the invention provides a device adapted for being mounted on a wheelchair, the device comprising a chassis, fastening means with guide brackets and a locking mechanism, and an auxiliary means such as a docking fixture, drive unit, battery pack, or shelf, wherein a guide rod mounted to the chassis is configured to slide or roll within guide recesses of the brackets to correctly position the chassis relative to the wheelchair.

[0018] In a second aspect, the invention provides a wheelchair comprising the above device, wherein the guide recesses are preferably arranged such that the guide rod is guided under gravitational assistance, and the locking mechanism secures the chassis in position following correct alignment.

[0019] In a third aspect, the invention provides a method for mounting an auxiliary means to a wheelchair, the method comprising pre-mounting guide brackets to the wheelchair, inserting a guide rod into guide recesses, and securing a locking mechanism to affix the chassis in position.

[0020] In a fourth aspect, the invention provides a retrofit kit for equipping an existing wheelchair with an auxiliary means, the kit comprising a chassis, a guide rod, a set of guide brackets, and a locking mechanism, the components being configured to allow quick and secure attachment without modification of the wheelchair frame. Each of these aspects contributes to the overall goal of enhancing the functionality, safety, and usability of wheelchairs for everyday use, transport, and emergency situations.

[0021] Brief description of the figures

[0022] Figure 1 shows a device in accordance with various embodiments of the invention mounted on a wheelchair.

[0023] Figure 2 shows a perspective view of a device in accordance with various embodiments of the invention.

[0024] Figure 3 shows a closeup view of a part of Figure 1.

[0025] Figure 4 shows a bottom view of a part of a device in accordance with various embodiments of the invention.

[0026] Figure 5 shows an exploded view of a device in accordance with various embodiments of the invention.

[0027] Figure 6 shows a side view of a device in accordance with various embodiments of the invention.

[0028] Figures 7A-C show the process of dismounting a mounting rod end from a locking bracket.

[0029] Figures 8A-C show the process of dismounting a mounting rod end from a locking bracket. Figure 9 is a perspective and partly transparent view of a mounting rod end in accordance with various embodiments of the invention.

[0030] Figure 10 is a perspective of a docking fixture mounted to a part of the chassis.

[0031] Detailed description of the invention

[0032] The following detailed description sets forth illustrative embodiments of the invention, which should be considered in all respects as non-limiting. The embodiments are described with reference to the accompanying drawings, in which, like reference numerals identify corresponding elements. While specific features are shown and described in connection with particular configurations, it will be understood that various modifications and combinations of components may be made without departing from the scope of the invention as defined in the appended claims.

[0033] Unless otherwise stated, directional terms such as "front", "rear", "upper", "lower", or "beneath" refer to orientations relative to the typical use or installation of a wheelchair in a transport or operational context. Terms such as "mounted", "secured", or "releasably connected" refer to either direct or indirect attachment unless explicitly stated otherwise.

[0034] As used in the specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" or "approximately" one particular value and / or to "about" or "approximately" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about", it will be understood that the particular value forms another embodiment. It should be noted that embodiments and features described in the context of one of the aspects of the present invention also apply to the other aspects of the invention.

[0035] Aspects of the invention

[0036] In one aspect, the invention provides:

[0037] A device adapted for being mounted on a wheelchair, the device comprising:

[0038] - a chassis;

[0039] - fastening means adapted for releasably securing the chassis to the wheelchair; and

[0040] - auxiliary means, such as a first female or male docking fixture, an auxiliary drive unit, parts of an auxiliary drive unit, a battery pack, or a shelf, the auxiliary means being adapted for being directly or indirectly mounted to the chassis; wherein the fastening means comprises:

[0041] - a set of guide brackets each with a guide recess, and adapted for being mounted to the wheelchair;

[0042] - a guide rod mounted to the chassis and operably connectable to the guide recesses; and

[0043] - a locking mechanism partly arranged on the chassis and on the set of guide brackets; wherein the set of guide brackets are adapted to be pre-mounted to the wheelchair prior to mounting the chassis; wherein the guide recess comprises a linear guide slot section with an open end and a closed end, wherein the guide rod is configured to be inserted into the open end of the linear guide slot section, and wherein the guide rod is configured for sliding, or rolling, if rollers or wheels are mounted to the guide rod, within the guide recesses, thereby allowing a user to correctly position the chassis relative to the wheelchair. In a second aspect, the invention provides:

[0044] A wheelchair with a front end and a rear end, the wheelchair comprising a device according to any one of the preceding aspects.

[0045] In a third aspect, the invention provides:

[0046] A method for mounting an auxiliary means to a wheelchair, the method comprising:

[0047] - pre-mounting a set of guide brackets to the wheelchair;

[0048] - sliding or rolling a guide rod mounted to a chassis carrying the auxiliary means into guide recesses of the guide brackets; and

[0049] - engaging a locking mechanism to secure the chassis to the wheelchair.

[0050] In a fourth aspect, the invention provides:

[0051] A retrofit kit for equipping a wheelchair with an auxiliary means, the kit comprising:

[0052] - a chassis;

[0053] - a set of fastening components configured for releasably securing the chassis to the wheelchair; and

[0054] - an auxiliary means selected from the group consisting of a first female or male docking fixture, an auxiliary drive unit, parts of an auxiliary drive unit, a battery pack, or a shelf, the auxiliary means being adapted for direct or indirect mounting to the chassis; wherein the fastening components comprise:

[0055] - a set of guide brackets, each having a guide recess with a linear guide slot section having an open end and a closed end, the guide brackets being configured for mounting to the wheelchair;

[0056] - a guide rod mounted to the chassis and configured for sliding or rolling, if rollers or wheels are mounted thereto, within the guide recesses; and

[0057] - a locking mechanism partly arranged on the chassis and partly on the set of guide brackets; wherein the guide rod is insertable into the open end of the guide slot section and guided toward the closed end to position the chassis relative to the wheelchair for engagement by the locking mechanism.

[0058] Overview and general configuration

[0059] Referring to Figure 1 , the general scheme of the invention is shown. In general, the device is preferably adapted for being mounted beneath a wheelchair.

[0060] The chassis’ main function is to act as support for the auxiliary means, although it may also function to prevent a foldable wheelchair from folding during use. The chassis may also have other functions, such as serving to level the auxiliary means relative to the wheelchair. Other functions may be to provide support for other parts, or for taking part in adjustment features. The chassis may have many different configurations, especially depending on its secondary purposes.

[0061] Fastening means and guide system

[0062] The fastening means may have many different configurations, but as a minimum comprising set of guide brackets, a guide rod, and locking mechanism. The fastening means allows a user to be guided during the mounting operation of the auxiliary means, i.e., the guide brackets serve to guide the auxiliary means into position on or preferably beneath the wheelchair. The guide rod is mounted to the chassis and is configured to move within the guide recesses of the guide brackets.

[0063] The guide recess comprises a linear guide slot section with an open end and a closed end, and wherein the guide rod is configured to be inserted into the open end of the linear guide slot section. In one or more embodiments, the fastening means may be implemented as a universal interface for various auxiliary modules. The system can be adapted for interchangeability, allowing a user to swap different auxiliary devices using the same base interface of guide brackets and locking features.

[0064] Cam slot section and haptic feedback

[0065] In one or more embodiments, the guide recess comprises a linear guide slot section followed by a cam slot section, and wherein the guide rod is configured to be inserted into an opening in the linear guide slot section.

[0066] The cam slot section provides a controlled, curved, or complex motion based on the shape of the slot. One advantage of this is to provide the user with haptic feedback to indicate that the auxiliary means is in position relative to the wheelchair, or a part thereof. The cam slot can be designed to include features that create tactile feedback when the guide rod moves into a specific position. The curve may, e.g., create a bump when the guide rod moves past it. In an alternative embodiment, the linear guide slot section is provided with an indent configured to create a bump when the guide rod moves past it. Another advantage of the cam slot is fixation in a specific position. The configuration of the cam slot section may make it more difficult for the guide rod to return to the linear guide slot section.

[0067] Locking mechanism

[0068] The final part of the mounting operation is when the locking mechanism, partly arranged on the chassis and on the set of guide brackets, is activated, thereby securing the auxiliary means to the wheelchair.

[0069] In one or more embodiments, the locking mechanism comprises:

[0070] - a set of locking brackets, preferably each adapted for being mounted to each guide bracket; and - a mounting rod with a first end and a second end and fastened to the chassis, wherein each end is adapted for releasably engagement to each of said locking brackets.

[0071] In one or more embodiments, the mounting rod comprises a first end and an opposite second end, and wherein each end is configured as a locking pin adapted for releasably engagement with a respective bracket of said first set of brackets. The locking pin may comprise a neck and a head. The bracket may comprise a recess adapted for receiving the neck of the locking pin. The head of the locking pin may be wider than the recess, thereby restricting movement of the first mounting rod during impact.

[0072] In one or more embodiments, each locking bracket comprises a cavity; wherein the fastening means further comprises a pair of sleeve units each adapted for sliding back and forth on said mounting rod between an extended position and a retracted position relative to the first or second end, respectively, of said first mounting rod, wherein each sleeve unit of said pair of sleeve units comprises a first end and a second end, wherein the first end of each sleeve unit is configured for releasably engagement with a cavity of a respective bracket of said first set of brackets.

[0073] In one or more embodiments, each sleeve unit comprises a spring-loaded mechanism configured for forcing said sleeve unit towards its extended position and for resiliently allowing said sleeve unit to be positioned in its retracted position by a user.

[0074] In one or more embodiments, the locking mechanism comprises spring- loaded components or sleeve units that can be engaged by the user using a single hand. This simplifies the locking process, making the system suitable for users with limited dexterity. Chassis design and adjustability

[0075] The device is preferably U-shaped or tubular. This is to provide space for tools to handle (tighten or loosen) bolt nuts or screws mounted or being part of the device when adjustments are needed.

[0076] Auxiliary means

[0077] In one or more embodiments, the auxiliary means is selected from the group consisting of an auxiliary drive unit, parts of an auxiliary drive unit, a battery pack, or a shelf.

[0078] In one or more embodiments, the wheelchair is a foldable wheelchair, and wherein the device is adapted for preventing the wheelchair from folding when mounted thereto.

[0079] In one or more embodiments, the auxiliary means is a first female or male docking fixture adapted for locking engagement with a respective second male orfemale docking fixture mounted to the floor of a transport vehicle.

[0080] The first female or male docking fixture may have many different configurations e.g., depending on the configuration of the second male or female docking fixture mounted to the floor of the transport vehicle. The docking fixture may e.g., be a male docking fixture, and e.g., comprise an upper portion (in use), a middle-positioned neck portion, and a lower positioned head portion. In order to induce mechanical strength into the docking fixture, the upper portion (in use) may be configured with a bottom plate (in use) with walls (e.g., two opposite side walls, and two opposite end walls, in use) optionally extending upwards therefrom. The walls, preferably the side walls, may be provided with the above disclosed bolt holes and / or guide recesses formed in the docking fixture. The auxiliary means may also include integrated electrical connectors configured to engage automatically with a corresponding electrical interface on the wheelchair or vehicle, thereby supporting powered accessories or communication links without manual cabling.

[0081] Wheelchair assembly and guide recess configuration

[0082] A second aspect relates to a wheelchair with a front end and a rear end, the wheelchair comprising a device according to the present invention.

[0083] In one or more embodiments, the guide recess comprises an open end, and a closed end.

[0084] In one or more embodiments, the guide brackets are arranged such that the closed ends of the guide recesses are pointing downwards towards the ground on which the wheelchair is positioned.

[0085] In one or more embodiments, the brackets are arranged such that the guide recesses are parallel relative to each other, with their open end facing the front end of the wheelchair and their closed end facing the rear end of the wheelchair, or vice versa.

[0086] In one or more embodiments, the chassis may be tilted about an axis defined by the guide rod, when said guide rod is positioned within the guide recesses, preferably solely prior to activation of the locking mechanism. This configuration allows the locking mechanism to be assembled by approaching the part of the locking mechanism arranged on the chassis with the part of the locking mechanism arranged on the set of guide brackets.

[0087] Retrofit kit for existing wheelchairs In one or more embodiments, the invention relates to a retrofit kit configured for mounting an auxiliary means to an existing wheelchair. The kit comprises a chassis adapted for supporting an auxiliary means, a guide rod mounted to the chassis, a set of guide brackets with guide recesses configured for mounting to a frame portion of the wheelchair, and a locking mechanism for releasably securing the chassis to the guide brackets. The guide rod is configured to engage the guide recesses of the brackets by sliding or rolling motion, thereby positioning the chassis correctly beneath or adjacent to the wheelchair. The kit may be supplied preassembled or in modular components and is intended for use with both new and pre-owned wheelchair models.

[0088] Universal fastening system

[0089] In one or more embodiments, the invention provides a modular fastening system comprising a set of guide brackets, a guide rod, and a locking mechanism. This system enables the secure and repeatable attachment of a variety of auxiliary components to a wheelchair frame. The guide brackets include a linear slot and optionally a cam slot section to guide the guide rod into position. The system allows for both tool-free installation and consistent mechanical alignment between the wheelchair and the auxiliary means.

[0090] The fastening system may be used independently of a specific auxiliary unit and may serve as a base interface for interchangeable equipment such as auxiliary drive units, battery packs, trays, or docking fixtures.

[0091] One-handed and ergonomic operation

[0092] In one or more embodiments, the device is designed for ergonomic use, enabling the attachment and detachment of the auxiliary means using only one hand. This functionality is especially beneficial for users with limited motor control or use of only one upper limb. One-handed operation is facilitated by the alignment geometry of the guide brackets, the gravitational settling of the guide rod, and the intuitive engagement of the spring-loaded locking mechanism. The handle may be positioned for optimal reach from a seated position, and components may include detents or tactile feedback features to confirm proper engagement.

[0093] Integrated electrical docking interface

[0094] In one or more embodiments, the chassis or auxiliary means may incorporate one or more electrical connectors adapted to engage corresponding connectors on the wheelchair or vehicle-mounted docking fixture. These connectors may include conductive pins, magnetic coupling features, or spring-loaded contacts to ensure proper electrical connection during docking. The electrical interface may facilitate power transfer for charging battery packs, operating drive units, or data communication with onboard control systems. The connectors are preferably integrated in a way that enables automatic engagement and disengagement without requiring user manipulation of separate cables.

[0095] Variations, materials, and applications

[0096] The components of the device, including the guide rod, sleeve units, and locking brackets, may be manufactured from a variety of materials suitable for mechanical durability, low friction, and biocompatibility. Examples include stainless steel, aluminum alloys, and polymers such as POM, PA, UHMWPE, PEEK, or PTFE. The device may be used in private or public transport scenarios, home care environments, hospitals, or emergency evacuation situations. It may also be integrated into rehabilitation or training devices or configured for modular laboratory equipment for mobility testing.

[0097] Guide recess configured as a guide rail

[0098] In one or more embodiments, each guide recess is configured as a guide rail. The term “guide rail” refers to a longitudinal recess, channel, or track with raised sides or defined geometry that constrains the guide rod in one or more lateral directions while allowing controlled linear or rolling movement along the slot axis. The guide rail configuration serves to ensure accurate alignment between the chassis and the wheelchair during insertion and to prevent undesired transverse displacement during operation or transport. The guide rail may be integrally formed with the guide bracket or assembled from multiple components.

[0099] Tactile detents and audible click feedback

[0100] In one or more embodiments, the sleeve units are configured to provide tactile or audible feedback upon engagement with the locking brackets. This may be achieved by incorporating mechanical detents, resilient clips, or frictional ridges on the outer surfaces of the sleeve units or on the cavities of the locking brackets. When the sleeve unit reaches its fully extended or retracted position, it may snap into place with a perceptible click, thereby confirming to the user that the mechanism has securely locked or unlocked. This feedback improves usability, particularly for visually impaired users or when operating under limited visibility or time pressure.

[0101] Tool-free operation of the locking mechanism

[0102] In one or more embodiments, the locking mechanism is fully operable without the need for separate tools. All components, including sleeve units, mounting rod, and locking brackets, are designed for manual engagement and disengagement. The sleeve units may be spring-biased toward their extended positions and movable by simple hand pressure. The locking brackets may include lead-in chamfers or snap-fit geometries that enable the sleeve units to engage automatically during insertion. This design ensures rapid deployment or removal of the chassis, particularly valuable in emergency scenarios or by users with limited access to tools.

[0103] Tilting of the chassis about the guide rod axis In one or more embodiments, the guide rod and guide recess are configured to allow the chassis to tilt, e.g., slightly, about the longitudinal axis defined by the guide rod when positioned within the guide recesses. This tilting motion may occur due to loose tolerances, curved recess profiles, or intentional clearance within the slot structure. The tilting feature facilitates vertical alignment of the locking mechanism, particularly when the guide rod has reached the end of the guide recess. This rotational freedom allows the user to easily bring the sleeve units or mounting rod ends into alignment with the locking brackets, thereby simplifying engagement.

[0104] Releasable engagement of sleeve unit with locking bracket

[0105] In one or more embodiments, each sleeve unit is configured for releasable engagement with a cavity formed in the locking bracket. The sleeve unit may include a chamfered or radiused lead-in at its first end, which aligns with the cavity during insertion. Upon alignment, the sleeve unit may snap into or nest within the cavity via interference fit, spring compression, or magnetic retention. Disengagement is accomplished by drawing the sleeve unit back along the mounting rod, overcoming the retention force. The mechanism ensures reliable and repeatable engagement without complex manipulation.

[0106] Adjustment points accessible via U-shaped or tubular frame

[0107] In one or more embodiments, the chassis comprises adjustment points that are accessible via openings integrated into a U-shaped or tubular frame. These openings may include cutouts, elongated slots, or access holes positioned adjacent to bolts, set screws, or alignment pins used to adjust the orientation or height of the auxiliary means. The U-shaped structure allows tools or fingers to reach these points without removing the chassis from the wheelchair, enabling fine-tuning during installation or servicing. The adjustability supports various auxiliary device configurations and accommodates different wheelchair geometries. Single-Handed Operation

[0108] In one or more embodiments, the device is designed for single-handed operation. This includes ergonomic placement of the handle on the chassis, spring-loaded actuation of the locking mechanism, and self-aligning features, such as gravity-assisted insertion of the guide rod into the guide recesses. The locking mechanism may be engaged by pulling or pushing a single sleeve unit or operating a lever that simultaneously actuates both sides of the mechanism. This configuration allows users with limited dexterity or use of only one upper limb to independently attach or detach the auxiliary means, improving accessibility and autonomy.

[0109] In the present context, the term "releasably securing" refers to a mechanical connection that can be repeatedly engaged and disengaged without permanent deformation or damage to the parts. For example, the guide rod or mounting rod may include features such as spring-loaded detents, snap-fit geometries, or sliding sleeves that engage with corresponding recesses or cavities in the brackets. This allows the user to attach or detach the chassis from the wheelchair without tools or permanent fastening elements. Engagement may be maintained by friction, spring tension, or mechanical locking features.

[0110] In one or more embodiments, each guide recess is configured as a guide rail. A guide rail in this context refers to a channel, groove, or open slot with defined geometry that guides and constrains the movement of the guide rod along a preferred path. This may include U-shaped channels, recessed tracks, or profiles with raised side edges that prevent lateral misalignment of the guide rod. The guide rail structure ensures accurate and repeatable alignment of the chassis with the wheelchair frame during insertion. In one or more embodiments, the auxiliary means is mounted directly or indirectly to the chassis. Direct mounting may include bolting or latching the auxiliary device to a dedicated interface surface on the chassis. Indirect mounting may involve an intermediate bracket, hinge, or docking plate that connects the auxiliary means to the chassis. This flexibility allows the system to accommodate a variety of auxiliary components with differing attachment requirements or dimensions.

[0111] In one or more embodiments, the auxiliary means is mounted directly or indirectly to the chassis. Direct mounting may include bolting or latching the auxiliary device to a dedicated interface surface on the chassis. Indirect mounting may involve an intermediate bracket, hinge, or docking plate that connects the auxiliary means to the chassis. This flexibility allows the system to accommodate a variety of auxiliary components with differing attachment requirements or dimensions.

[0112] In one or more embodiments, the guide rod is configured for sliding or rolling engagement within the guide recesses. The guide rod may function purely by low-friction sliding contact with the guide recess surface.

[0113] Alternatively, rollers or wheels may be mounted at one or both ends of the guide rod to reduce resistance and facilitate smoother insertion. The design is such that either configuration, sliding or rolling, achieves the intended alignment and positioning of the chassis relative to the wheelchair.

[0114] In one or more embodiments, each sleeve unit comprises a spring-loaded mechanism to aid in locking and unlocking. A compression spring may be positioned within the sleeve, biasing it toward its extended position. When the user retracts the sleeve manually, the spring is compressed. Releasing the sleeve causes it to extend and engage with a cavity in the locking bracket. This configuration allows reliable and repeatable engagement while simplifying the operation for the user. In one or more embodiments, the device is configured for tool-free operation. This means that the user is not required to use separate hand tools, such as screwdrivers, wrenches, or keys, to attach or detach the chassis from the wheelchair. Locking and unlocking are accomplished manually, by pushing, pulling, or sliding components such as sleeve units or rods. Components may include textured grip zones or ergonomic contours to assist manual actuation.

[0115] In one or more embodiments, the system is operable using a single hand. The handle may be positioned within easy reach of a seated user, and the locking mechanism may be actuated by a single linear motion. The guide rod and recesses assist in passive alignment so that both hands are not needed for stabilization. Components such as spring-loaded sleeves or self-aligning brackets ensure that the user can mount or dismount the device independently, even if limited to one functional upper limb. This is particularly beneficial for users with hemiparesis, amputations, or other mobility impairments.

[0116] Figures and material details

[0117] Figure 1 shows a device 100 mounted on the chassis of a wheelchair 50. The auxiliary means is here embodied as a male docking fixture 140 adapted for releasably securing the wheelchair 50 to the floor of a transport vehicle (not shown).

[0118] Now referring to Figure 2 for a better view of the device, the device 100 comprises a chassis 110, a fastening means 122-124, 131-132 adapted for releasably securing the chassis 110 to the wheelchair 50, and auxiliary means 140 mounted to the chassis 110. The fastening means comprises a set of guide brackets 122A, 122B (preferably made of metal, such as steel, stainless steel, aluminum, or brass), each with a guide recess 123 (with an open end and a closed end), adapted for being mounted to the wheelchair 50 via clamp units 150 (four are shown). A guide rod 124 is mounted to the chassis 110 and is operably connectable to the guide recesses 123A, 123B, i.e. , it is capable of sliding or rolling (if rollers or wheels are mounted to the guide rod) within the guide recesses 123A, 123B, thereby allowing a user to correctly position the chassis relative to the wheelchair 50. The guide recess 123 is here shown comprising a linear guide slot section 127 (see Figure 6) followed by a cam slot section 128. The guide rod 124 is configured to be inserted into an opening in the linear guide slot section 127, while the cam slot section 128 defines the closed end of the guide recess 123.

[0119] Using polymeric materials for the guide rod or parts thereof to be operating within the guide slots is preferable because these materials provide good wear resistance, low friction, and durability. One of the most widely used polymers for such purpose is polyoxymethylene (POM), also known as acetal. POM is valued for its high stiffness, low friction, excellent dimensional stability, and good wear resistance, making it ideal for precision parts like gears, bushings, and followers. Nylon, or Polyamide (PA), is another popular choice due to its high mechanical strength, good wear resistance, low friction, and good impact resistance. Ultra-High Molecular Weight Polyethylene (UHMWPE) offers extremely high wear resistance, low friction, high impact resistance, and self-lubricating properties, making it suitable for such high-wear applications. Polyether Ether Ketone (PEEK) is also known for its high mechanical strength, excellent chemical resistance, high-temperature resistance, and good wear properties. Polyethylene Terephthalate (PET) is another suitable polymer, offering good mechanical strength, excellent wear resistance, low moisture absorption, and good dimensional stability, making it ideal for this purpose. Finally, polytetrafluoroethylene (PTFE) stands out for its extremely low friction, excellent chemical resistance, high temperature resistance, and good wear resistance. The guide brackets 122A, 122B may also be made from the same polymers as discussed above.

[0120] Mounting geometry and user orientation

[0121] In general, the guide brackets 122A, 122B may, when mounted to the wheelchair, be arranged such that the closed ends of the guide recesses 123A, 123B are pointing towards the ground on which the wheelchair is positioned. This configuration aids the user during the mounting operation of the chassis 110 and attached auxiliary means 140 as it will, due to gravitational force, more easily fall into place. In the specific disclosed embodiment, the brackets 122A, 122B are, when mounted to the wheelchair, also arranged such that the guide recesses 123A, 123B are parallel relative to each other and with the open end facing the front (see Figures 1 and 3) of the wheelchair. This parallel arrangement is also generally applicable. When the open end faces the front of the wheelchair, a user may mount the chassis 110 and attached auxiliary means 140 when seated.

[0122] Locking mechanism in detail

[0123] The fastening means also comprises a locking mechanism 130, partly arranged on the chassis 110 and on the set of guide brackets 122A, 122B. In this specific embodiment (see Figures 3 and 5), the locking mechanism 130 comprises a set of locking brackets 132A, 132B mounted to the guide brackets 122A, 122B, and a mounting rod 134 with a first end 136 and an opposite second end 137 and fastened to the chassis 110 (here via an operating handle 126). The ends 136, 137 of the mounting rod 134 are adapted for releasably engagement to each of said locking brackets 132A, 132B. Each end 136, 137 (Figures 7 and 8 show the first end 136, while Figure 9 shows the second end 137) is configured as a locking pin adapted for releasably engagement with a respective locking bracket 132A, 132B. The locking pin is here shown with a head and a neck. The neck is configured to fit into a recess of the bracket, while the head aids in restricting the movement of the locking pin relative to the locking bracket 132A, 132B once the two are connected. Each locking bracket 132A, 132B also comprises a cavity 133 (see Figure 7), here shown flanking the recess. The fastening means 130 is shown further comprising a pair of sleeve units 131 A, 131 B each adapted for sliding back and forth on the mounting rod 134 between an extended position (Figures 7A and 8A) and a retracted position (Figures 7B and 8B) relative to the first 136 or second 137 end, respectively, of the mounting rod 134. Each sleeve unit 131 A, 131 B comprises a first end 138A, 138B and a second end 139A, 139B, wherein the first end 138A, 138B of each sleeve unit 131 A, 131 B is configured for releasably engagement with a cavity 133 of a respective locking bracket 132A, 132B. Hence, in the extended position, the sleeve unit 131 A is locked to the locking bracket 132A (Figures 7A and 8A), and in the retracted position, the sleeve unit 131 A is unlocked from the locking bracket 132A (Figures 7B and 8B).

[0124] Each sleeve unit 131 A, 131 B is shown (see Figure 9) comprising a spring- loaded mechanism with a spring 135 configured for forcing the sleeve unit 131 A, 131 B towards its extended position and for resiliently allowing the sleeve unit 131 A, 131 B to be positioned in its retracted position by a user. This configuration makes it easier for the user merely to lift, by the aid of the handle 126 (see Figure 5), the mounting rod 134 into place, after the guide rod 124 has been correctly placed within the guide recesses 123A, 123B (more specifically within the cam slot sections 128).

[0125] The device 100 is U-shaped or tubular. This is to provide space for tools to handle (tighten or loosen) the bolt nuts when adjustments are needed. The docking fixture 140 could have many different configurations but is here shown with a neck portion 142, and a lower positioned head portion 144 (see Figure 10). References

[0126] 50 Wheelchair

[0127] 100 Device

[0128] 110 Chassis

[0129] 122 Guide bracket

[0130] 123 Guide recess

[0131] 124 Guide rod

[0132] 125 Spacer plate

[0133] 126 Handle

[0134] 127 Linear guide slot section

[0135] 128 Cam slot section

[0136] 130 Locking mechanism

[0137] 131 Sleeve unit

[0138] 132 Locking bracket

[0139] 133 Cavity

[0140] 134 Mounting rod

[0141] 135 Spring

[0142] 136 First end

[0143] 137 Second end

[0144] 138 First end

[0145] 139 Second end

[0146] 140 First docking fixture

[0147] 142 Neck portion

[0148] 144 Head portion

[0149] 150 Clamp unit

Claims

Claims1 . A device (100) adapted for being mounted on a wheelchair (50), said device (100) comprising:- a chassis (110);- fastening means adapted for releasably securing the chassis (110) to the wheelchair (50); and- auxiliary means, such as a first female or male docking fixture (140), an auxiliary drive unit, parts of an auxiliary drive unit, a battery pack, or a shelf, said auxiliary means adapted for being directly or indirectly mounted to said chassis (110); wherein the fastening means comprises:- a set of guide brackets (122A, 122B) each with a guide recess (123A, 123B), and adapted for being mounted to the wheelchair (50);- a guide rod (124) mounted to the chassis (110) and operably connectable to said guide recesses (123A, 123B); and- a locking mechanism (130) partly arranged on the chassis (110) and on the set of guide brackets (122A, 122B); wherein the set of guide brackets (122A, 122B) are adapted to be premounted to the wheelchair (50), prior to mounting the chassis (110); characterized in that the guide recess (123) comprises a linear guide slot section with an open end and a closed end, wherein the guide rod (124) is configured to be inserted into the open end of the linear guide slot section, and wherein said guide rod (124) is configured for sliding, or rolling, if rollers or wheels are mounted to the guide rod, within the guide recesses (123A, 123B), thereby allowing a user to correctly position the chassis relative to the wheelchair (50).

2. The device (100) according to claim 1 , wherein each guide recess (123A, 123B) is configured as a guide rail.

3. The device (100) according to claim 1 , wherein the guide recess (123) comprises a linear guide slot section (127) followed by a cam slot section (128), and wherein the guide rod (124) is configured to be inserted into an opening in the linear guide slot section (127).

4. The device (100) according to any one of the claims 1-3, wherein the locking mechanism (130) comprises:- a set of locking brackets (132A, 132B), preferably each adapted for being mounted to each guide bracket (122A, 122B); and- a mounting rod (134) with a first end and a second end and fastened to the chassis (110), wherein each end is adapted for releasably engagement to each of said locking brackets (132A, 132B).

5. The device (100) according to claim 4, wherein each locking bracket (132A, 132B) comprises a cavity (133); wherein said fastening means (130) further comprises a pair of sleeve units (131 A, 131 B) each adapted for sliding back and forth on said mounting rod (134) between an extended position and a retracted position relative to the first or second end, respectively, of said first mounting rod (134), wherein each sleeve unit(131 A, 131 B) comprises a first end (136) and a second end (138), wherein the first end (136) of each sleeve unit (131 A, 131 B) is configured for releasably engagement with the cavity (133) of a respective locking bracket (132A, 132B).

6. The device (100) according to claim 5, wherein each sleeve unit (131 A, 131 B) comprises a spring-loaded mechanism (135) configured for forcing said sleeve unit (131 A, 131 B) towards its extended position and for resiliently allowing said sleeve unit (131 A, 131 B) to be positioned in its retracted position by a user.

7. The device (100) according to any one of the claims 1-6, wherein theauxiliary means is selected from the group consisting of an auxiliary drive unit, parts of an auxiliary drive unit, a battery pack, or a shelf.

8. The device (100) according to any one of the claims 1-6, wherein the auxiliary means is a first female or male docking fixture (140) adapted for locking engagement with a respective second male orfemale docking fixture mounted to the floor of a transport vehicle.

9. The device (100) according to any one of the claims 1-8, further comprising a handle (126) mounted to the chassis (110).

10. A wheelchair (50) with a front end and a rear end, the wheelchair (50) comprising a device (100) according to any one of the claims 1-9.11 . The wheelchair (50) according to claim 10, wherein the auxiliary means is a first female or male docking fixture (140) adapted for locking engagement with a respective second male orfemale docking fixture mounted to the floor of a transport vehicle.

12. The wheelchair (50) according to claim 11 , wherein the guide brackets (122A, 122B) are arranged such that the closed ends of the guide recesses (123A, 123B) are pointing downwards towards the ground on which the wheelchair (50) is positioned.

13. The wheelchair (50) according to any one of the claims 10-12, wherein the brackets (122A, 122B) are arranged such that the guide recesses (123A, 123B) are parallel relative to each other, with their open end facing the front end of the wheelchair (50) and their closed end facing the rear end of the wheelchair (50), or vice versa.

14. The wheelchair (50) according to any one of the claims 10-13, whereinthe chassis (110) may be tilted about an axis defined by the guide rod (124), when said guide rod (124) is positioned within the guide recesses (123A, 123B), preferably solely prior to activation of the locking mechanism.

15. The wheelchair (50) according to any one of the claims 10-13, wherein the auxiliary means is selected from the group consisting of an auxiliary drive unit, parts of an auxiliary drive unit, a battery pack, or a shelf.

16. The device (100) according to claim 3, wherein the cam slot section (128) is configured to provide haptic feedback to the user during engagement of the guide rod (124) with the guide recesses (123A, 123B).

17. The device (100) according to any one of claims 1-16, wherein the guide rod (124) comprises or is coated with a polymeric material selected from the group consisting of polyoxymethylene (POM), nylon (PA), ultra- high molecular weight polyethylene (UHMWPE), polyether ether ketone (PEEK), polyethylene terephthalate (PET), or polytetrafluoroethylene (PTFE).

18. The device (100) according to any one of claims 1-17, wherein the guide brackets (122A, 122B) are arranged on the wheelchair (50) such that the closed ends of the guide recesses (123A, 123B) point downward, allowing the guide rod (124) to settle into position under gravitational force.

19. The device (100) according to any one of claims 1-18, wherein the wheelchair (50) is a foldable wheelchair and the chassis (110) is configured to prevent the wheelchair (50) from folding when the device (100) is mounted.

20. The device (100) according to claim 9, wherein the handle (126) is positioned such that the locking mechanism (130) can be engaged ordisengaged using a single hand of a user.

21. The device (100) according to claim 5, wherein the sleeve units (131 A, 131 B) comprise tactile detents or audible click features that indicate full engagement or disengagement with the locking brackets (132A, 132B).

22. The device (100) according to any one of claims 1-21 , wherein the locking mechanism (130) is operable without tools.

23. The device (100) according to any one of claims 1-22, wherein the chassis (110) includes adjustment points accessible via openings in a U- shaped or tubular frame, allowing alignment of the auxiliary means (140).

24. A method for mounting an auxiliary means (140) to a wheelchair (50), the method comprising:- pre-mounting a set of guide brackets (122A, 122B) to the wheelchair (50);- sliding or rolling a guide rod (124) mounted to a chassis (110) carrying the auxiliary means (140) into guide recesses (123A, 123B) of the guide brackets (122A, 122B); and- engaging a locking mechanism (130) to secure the chassis (110) to the wheelchair (50).

25. The method according to claim 24, wherein the step of sliding or rolling the guide rod (124) further comprises guiding the guide rod into a cam slot section (128) that provides haptic feedback to the user.

26. The method according to any one of claims 24-25, further comprising tilting the chassis (110) about an axis defined by the guide rod (124) prior to engaging the locking mechanism (130).

27. The method according to any one of claims 24-26, wherein the lockingmechanism (130) is engaged by actuating a pair of spring-loaded sleeve units (131 A, 131 B) mounted on a mounting rod (134), each sleeve unit being pushed into locking engagement with a locking bracket (132A, 132B).

28. The method according to any one of claims 24-27, wherein the method is performed using a single hand of a user.

29. The method according to any one of claims 24-28, wherein the auxiliary means (140) is selected from the group consisting of an auxiliary drive unit, a battery pack, or a shelf.

30. The method according to any one of claims 24-29, wherein the guide brackets (122A, 122B) are arranged such that gravity assists the guide rod (124) in settling into the guide recesses (123A, 123B) during the mounting step.31 . A retrofit kit for equipping a wheelchair (50) with an auxiliary means, the kit comprising:- a chassis (110);- a set of fastening components configured for releasably securing the chassis (110) to the wheelchair (50); and- an auxiliary means selected from the group consisting of a first female or male docking fixture (140), an auxiliary drive unit, parts of an auxiliary drive unit, a battery pack, or a shelf, the auxiliary means being adapted for direct or indirect mounting to the chassis (110); wherein the fastening components comprise:- a set of guide brackets (122A, 122B), each having a guide recess (123A, 123B) with a linear guide slot section having an open end and a closed end, said guide brackets (122A, 122B) being configured for mounting to the wheelchair (50);- a guide rod (124) mounted to the chassis (110) and configured forsliding or rolling, if rollers or wheels are mounted thereto, within the guide recesses (123A, 123B); and- a locking mechanism (130) partly arranged on the chassis (110) and partly on the set of guide brackets (122A, 122B); wherein the guide rod (124) is insertable into the open end of the guide slot section and guided toward the closed end to position the chassis (110) relative to the wheelchair (50) for engagement by the locking mechanism (130).

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