Coupling device for the detachable connection of an assistive device to a wheelchair, as well as a wheelchair with such a coupling device

Abstract

Coupling device (12) for detachably connecting an auxiliary device (11) to a wheelchair (10), with a coupling element (13) and a coupling element receptacle (16) which has the following features: - a base body (23) in which a receiving opening (37) for receiving the coupling element (13) is formed; - a locking device (24) comprising a locking element (25) which is preloaded to move in the direction of the locking position (35) between an open position (36), in which the coupling element (13) can be inserted into and removed from the receiving opening (37), and a locked position (35), in which the coupling element (13) is held in the receiving opening (37) by the locking element (25), wherein the locking device (24) comprises a holding mechanism (44) which is configured to hold the locking element (25) in the open position (36) when it has been moved into the open position (36), and to release a movement of the locking element (24) in the direction of the locking position (35) when the coupling element (13) has been at least partially inserted into the receiving opening (37).

Description

[0001] The invention relates to coupling devices for the detachable connection of auxiliary devices to wheelchairs and wheelchairs with such coupling devices.

[0002] Wheelchairs are common knowledge. There are manual and electric wheelchairs. Manual wheelchairs are generally significantly lighter than wheelchairs with a built-in electric drive. Manual wheelchairs are typically moved either by the user manually, e.g., using handrims attached to the rear wheels of the wheelchair, or by an assistant pushing the wheelchair. Manual wheelchairs can be retrofitted with auxiliary drives to assist the user in moving the wheelchair.

[0003] Regardless of whether the wheelchair is manually or electrically powered, stairs pose a major obstacle. This poses a dangerous physical challenge for both the wheelchair user and the assistant attempting to negotiate the steps while seated in the wheelchair. For this reason, electric stair-climbing devices are available, such as those described in DE 10 2005 008 826 B3. These can usually be attached to the back of the wheelchair and, with the wheelchair user seated in the wheelchair, assist in transporting the wheelchair up and down stairs.

[0004] The coupling interfaces between the wheelchair and the assistive device, such as the stair climbing device or the auxiliary drive, are usually equipped with two lateral receptacles on the side of the wheelchair, each of which can accommodate an assistive device-side bolt. After inserting the assistive device-side bolts into the receptacles, the bolts can be secured in the receptacles, for example, with ball-lock pins. However, this requires considerable manual effort when coupling the assistive device to the wheelchair.

[0005] Other coupling mechanisms for assistive devices on wheelchairs are known from the state of the art.

[0006] EP 3 439 604 B1, for example, describes a coupling device in which a locking element is rotatably arranged at the opening of the coupling device such that the opening is open in a first position and closed in a second position. The locking element is pretensioned towards the open position by a torsion spring. When the bolt is inserted into the opening, it presses against the locking element, causing the latter to move into the closed position. It is held there by a release element. When the bolt is inserted into the receiving opening, the spring force of the torsion spring must be overcome. The torsion spring has a tendency to press the locking element into the open position, so that in practice, when the bolt is inserted into the receiving opening, the bolt can be inadvertently pushed out of the receptacle.This can be uncomfortable for the user when connecting the auxiliary drive to the wheelchair.

[0007] DE 20 2018 002 476 U1 also describes a device for coupling an auxiliary drive to a wheelchair point. The coupling device has a receptacle into which a connecting element is inserted from above and held there by a fixing element. However, lifting the auxiliary drive can be difficult and uncomfortable for the user. In addition, the fixing element is spring-loaded, so it tends to close the receptacle. When inserting the connecting element, it must work against the spring of the fixing element to be inserted into the receptacle.

[0008] Furthermore, EP 3 622 930 A2 discloses an auxiliary device for a wheelchair with an electrically driven wheel and a coupling mechanism for coupling the auxiliary device to the wheelchair. In the auxiliary device, the opening of the receptacle can be opened and closed with a locking element. The receptacle is only opened when a lever is pulled to lift and carry the auxiliary device.

[0009] Based on this, it is the object of the invention to provide an improved and comfortable coupling device for auxiliary devices on wheelchairs, with which the auxiliary devices can be coupled to the wheelchair as conveniently and easily as possible, in particular requiring few manual interventions.

[0010] The object of the invention is achieved by the coupling device according to claim 1 and the wheelchair according to claim 16.

[0011] The coupling device according to the invention for detachably connecting an auxiliary device to a wheelchair comprises in particular a coupling element and a coupling element receptacle, wherein the coupling element receptacle has the following: - A base body in which a receiving opening is formed for receiving the coupling element; and - A locking device with a locking element which is movable in a pre-loaded manner in the direction of the locking position between an open position in which the coupling element can be inserted and removed from the receiving opening and a locking position in which the coupling element is held in the receiving opening by the locking element.

[0012] The locking device has a holding mechanism which is designed to hold the locking element in the open position when it has been brought into the open position and to release a movement of the locking element in the direction of the locking position when the coupling element has been at least partially inserted into the receiving opening.

[0013] The locking device can be designed as a locking latch by the holding mechanism, which closes automatically, in particular due to the dead weight of the locking element, when the coupling element has been at least partially inserted into the receiving opening. The locking element of the locking device can preferably be moved with the foot into the open position, in which it is held by the holding mechanism, whereby the user does not have to bend down to move the locking device into the open position. When the coupling element has been inserted into the receiving opening of the coupling element receptacle, the locking device snaps shut, so that the locking element blocks the receiving opening and the coupling element is securely held in the receiving opening of the coupling element receptacle.Because the locking element is preloaded toward the locking position, the locking device closes the receiving opening directly when the coupling element in the receiving opening releases the locking element's mobility. In the locking position, the locking element preferably completely closes the receiving opening in a lateral projection.

[0014] It is preferred that the locking element is preloaded into the locking position by weight. The locking element is preferably designed as a locking lever that can be pivoted about a pivot axis and on the underside of which a locking recess is formed. The pivot element is preferably arranged such that a first end of the pivot element is mounted on the base body of the coupling element receptacle so that it can be pivoted about a pivot axis. The locking recess of the locking element and the receiving opening of the base body at least partially overlap in a lateral projection. The area in which the locking recess and the receiving opening overlap is designed to receive the coupling element in the locking position. The pivot axis of the locking element is preferably arranged on the base body such that the receiving opening is located between the pivot axis and the center of gravity of the locking element.The mouth of the receiving opening is thus closed in the lateral projection by the locking element when the locking element is in the locked position. For example, it can be arranged above and / or behind the receiving opening. The locking element can then be in an upper position in the open position, while in a lower position in the locked position. The weight acting on the locking element causes the locking element to pivot from the upper position like a rigid pendulum into the lower position when the mobility of the locking element is released by the holding mechanism. In the upper position, the holding mechanism locks the locking element so that the locking element initially remains in the upper position until the holding mechanism is released and the locking element is released. Driven by gravity, the locking element then pivots into the lower position and closes the receiving opening.Alternatively or additionally, the locking element can be biased into the lower position by a spring. The holding mechanism is preferably also configured to lock the locking element in the locked position when it is in the locked position. This prevents the coupling element from being pulled out of the receiving opening in the base body of the coupling element receptacle. For example, the holding mechanism can have a pawl whose tip engages with a locking contour formed on the locking element.

[0015] A special feature of the present invention is that, in addition to inserting the coupling element into the receiving opening, only a few or no further steps, such as inserting locking bolts for coupling or preparing the coupling receptacle for coupling or the like, are required to connect the auxiliary device.

[0016] The assistive device can be an electric stair-climbing device, such as that described in DE 10 2005 008 826 B3. Furthermore, the assistive device can also be an auxiliary drive designed to propel the wheelchair horizontally and thereby assist the user.

[0017] It is preferred that the release of the locking element can be triggered by the holding mechanism by means of the coupling element, so that the locking element automatically falls from the open position into the locked position when the coupling element has been at least partially inserted into the receiving opening.

[0018] The locking device preferably has at least one cover element in which the functional parts of the holding mechanism are housed. This protects the functional parts of the holding mechanism from external influences, such as impacts and shocks, as well as from contamination. The cover element can be attached to the base body of the coupling element receptacle. The locking device can thus be designed as a separate unit that can be attached to the base body via the cover element. This also allows the locking device to be subsequently attached to a conventional coupling element receptacle. Conventional coupling element receptacles can thus be retrofitted.

[0019] The locking device has, in particular, a pivot axis about which the locking element can be pivoted relative to the base body between the open position and the locked position. The pivot axis of the locking device is arranged, in particular, above the receiving opening of the base body. The pivot axis of the locking element is arranged, in particular, at a first end of the locking element, whereby the locking element is preloaded by its weight toward the locked position.

[0020] The blocking element is arranged, in particular in the blocking position, in such a way that the receiving opening of the base body is at least partially, preferably completely, closed in a lateral projection.

[0021] The locking element in particular has a locking recess whose inner contour is adapted to the outer contour of the coupling element. The locking recess is preferably open downwards, i.e. towards an underside of the locking element. The locking recess is in particular formed in the locking element in such a way that the distance to the first end is smaller than the distance to the second end of the locking element. The locking recess is preferably arranged near the pivot axis. Adjacent to the locking recess is in particular a locking projection which projects from the locking element transversely to the pivot axis. On a side facing away from the locking recess, the locking projection has a guide surface which is inclined in the insertion direction. The guide surface preferably forms an acute angle with the insertion direction in the lateral projection.This means that the locking element can also be in the locked position for coupling without first having to move it to the open position 36. The coupling element rubs along the guide surface of the locking element and pushes the locking element slightly upwards toward the open position until it has overcome the locking projection and is positioned in the receiving opening. The receiving opening is then closed by the locking element – ​​without any action from the user – through its own weight. The locking element is then returned to the locked position.

[0022] It is also preferred that the locking element be elongated, with the locking element being pivotably mounted at a first of its ends about the pivot axis from the open position to the locked position and vice versa. The pivot axis is preferably arranged transversely to an insertion direction of the coupling element. In particular, the pivot axis is oriented horizontally.

[0023] The locking element can further have an actuating surface at which it can be actuated with the foot, preferably with the tip of the foot, i.e. can be transferred (brought) from the locked position to the open position. The actuating surface is in particular dimensioned such that its maximum width, at least at one point, corresponds to a factor of the width of an average foot. The factor can, for example, be between 1.0 and 0.2, preferably between 0.9 and 0.3, more preferably between 0.8 and 0.4, and particularly preferably between 0.7 and 0.5. The width of the locking element can increase towards the second end in order to enlarge the actuating surface and thus make foot actuation more comfortable. For example, the locking element can be T-shaped, triangular, square, polygonal or a combination thereof in plan view, with or without rounded flanks or the like.

[0024] It is also preferred that the locking element has a first display surface and a second display surface, wherein the first display surface is only visible to a user standing behind the wheelchair when the locking element is in the locked position. The second display surface is only visible to a user standing behind the wheelchair when the locking element is in the open position. The first display surface can be distinguished from the second display surface by a visual feature. For example, the display surfaces can differ in color. The display surfaces can also be underlined by different patterns. Additionally or alternatively, the display surfaces can have different pictograms that signal to the user that the locking device is in the open position or the locked position.In a specific example, the first display surface is colored green, while the second display surface is colored red. Furthermore, the display surfaces can be arranged at different locations on the locking element. For example, the first display surface, which signals to the user that the locking element is in the locked position, can be arranged on an elongated upper side of the locking element. This upper side of the locking element can be arranged at a (slightly) incline towards the rear of the wheelchair when the locking element is in the locked position, whereby the first display surface can be better perceived by the user standing behind the wheelchair. The first display surface can, for example, be inclined at an angle between 5° and 30°, preferably between 10° and 25°, and more preferably between 15° and 20° relative to the horizontal. The second display surface, on the other hand, can be arranged in an end region of the locking element.The second display surface can be arranged at least substantially orthogonally to the first display surface. This results in the second display surface being invisible to the user when the locking element is in the locked position. In the open position, the end portion of the locking element faces upward. When the locking element is in the open position, the first display surface is invisible to the user standing behind the wheelchair, while the second display surface is visible.

[0025] The holding mechanism preferably comprises a pawl which engages with a holding contour formed on the locking element when the locking element is in the open position. The holding contour has, in particular, a holding projection with a holding step formed on a first flank of the holding projection and a locking step formed on a second flank of the holding projection. The holding projection is preferably designed asymmetrically. The holding projection protrudes, in particular, transversely to the pivot axis on the side of the locking element facing away from the second end of the locking element. This means that the height of the holding step differs from the height of the locking step. Preferably, the height of the holding step is greater than the height of the locking step.In the locking position, the pawl is preferably in engagement with the locking step, so that the locking element is locked in the locking position by the holding mechanism and withdrawal of the coupling element from the receiving opening is blocked by the locking element.

[0026] At the first end of the locking element, at which the pivot axis is arranged, the locking element preferably has a projection with a surface which projects in a lateral projection into the receiving opening of the base body when the locking element is in the open position, so that the locking element is rotated towards the locked position. As a result, the pawl is no longer engaged with the retaining projection when the coupling element is in the receiving opening. The locking element can then fall (driven by weight) from the open position into the locked position. During uncoupling, the surface of the projection serves to push the coupling element out of the receiving opening of the base body.

[0027] It is preferred that the base body, with the locking device mounted on it, be height-adjustable on the wheelchair. This allows the coupling device to be adapted to the seat height of the wheelchair.

[0028] The object of the invention is further achieved by a wheelchair with the coupling device of the above type and an auxiliary device. Preferably, the coupling element is attached to the auxiliary device, and the coupling element receptacle is attached to the wheelchair. Alternatively, the coupling element receptacle can be attached to the auxiliary device, and the coupling element can be attached to the wheelchair.

[0029] Further details of advantageous developments or details of the invention can be found in the drawings, the description, and the dependent claims. They show: Fig. 1 shows an example of a wheelchair with an auxiliary device which is detachably connected to the wheelchair by means of a coupling device; Fig. 2 a detailed view of the coupling device; Fig. 3 a schematic, side sectional view of the coupling device, in which the locking device is in the locking position and the coupling element is inserted into the coupling receptacle; Fig. 4 is a schematic, side sectional view of the coupling device with the locking device in the open position; Fig. 5 is a schematic, side sectional view of the coupling device, in which the locking device is in a position between the open position and the locked position; Fig. 6 is a schematic side sectional view showing the locking device in the locking position; Fig. 7-9 a first example of coupling the aid to the wheelchair in several side views; and Fig. 10-12 a second example of coupling the assistive device to the wheelchair in several side views.

[0030] Fig. 1 shows a wheelchair 10 to which an auxiliary device 11 is detachably connected by means of a coupling device 12. In the Fig. The auxiliary device 11 shown in Figure 1 is a stair climbing aid which can be mechanically connected to the rear of the wheelchair 10 by means of the coupling device 12.

[0031] At the auxiliary device 11, in the Fig. 1, a coupling element 13 is attached to the side. Furthermore, a further coupling element 14 is attached to the side of the auxiliary device 11. The coupling element 13 and the further coupling element 14 are both designed as coupling bolts. They are firmly attached to the side 15 of the auxiliary device 11 in such a way that they protrude laterally from the auxiliary device 11. In this example, the further coupling element 14 is arranged at a different height above the ground than the coupling element 13. In particular, the further coupling element 14 is arranged at a lower height above the ground than the coupling element 13. Furthermore, the further coupling element 14 is attached to the auxiliary device 11 further forward in the longitudinal direction of the auxiliary device 11 than the coupling element 13.

[0032] The coupling device 12 has a coupling element receptacle 16 configured to receive the coupling element 13. In the example shown, the coupling element 13 is attached to the auxiliary device side, and the coupling element receptacle 16 is attached to the wheelchair side. Alternatively, the coupling element 13 can be attached to the wheelchair side and the coupling element receptacle to the auxiliary device side.

[0033] The Fig. The coupling device 12 shown in Figure 1 also has a guide 17 arranged on the side 15 of the auxiliary device 11, which is configured to receive the additional coupling element 14. The guide 17 is also attached to the wheelchair side, while the additional coupling element 13 is attached to the auxiliary device side. Alternatively, the guide 17 can also be attached to the auxiliary device side, while the additional coupling element 14 is attached to the wheelchair side.

[0034] The guide 17 forms a rotation stop for the further coupling element 14, which can be inserted into the guide 17 when the auxiliary device 11 is detachably connected to the wheelchair 10 and in which the auxiliary device 11 is pivotally mounted.

[0035] The coupling element holder 15 is designed to be height-adjustable and attachable to the wheelchair 10. In the Fig. 1, the wheelchair 10 has a mounting plate 18 with a plurality of mounting holes to which the coupling element holder 15 can be attached to the wheelchair 10 at different heights above the ground.

[0036] The coupling device 12 is identically constructed on both sides 15 of the auxiliary device 11. In this example, a coupling element 13, another coupling element 14, a coupling element receptacle 16, and a guide 17 are arranged on each side 15.

[0037] Fig. 2 shows a detailed view of the Fig. 1 illustrated example of the coupling device 12. The coupling element holder 16 has a base body 23 with a receiving opening 37 for receiving the coupling element 13. In Fig. In Figure 2, the receiving opening 37 is obscured due to the perspective. The coupling element receptacle 16 has a locking device 24 with a locking element 25.

[0038] The locking element 25 is designed as a lever that extends elongately between a first end 27 and a second end 29. At the first end 27, the locking element 25 is pivotally mounted on the base body 23 about a (horizontally oriented) pivot axis 28. The locking element 25 can be pivoted up and down. Between the first end 27 and the second end 29, the locking element 25 has a locking recess 34, the inner contour of which is adapted to the outer contour of the coupling element 13 and is open downwards. The locking recess 34 is open toward the underside 49 of the locking element 25.The pivot axis 28 of the locking element 25 is arranged in an upper region of the base body 23 behind the receiving opening 37 thereon, so that the receiving opening 37 is closed in the lateral projection of the locking element 25 when it has been pivoted downward into the locking position 35, and is open in the lateral projection when it has been pivoted upward into the open position 36. Furthermore, the locking element 25 is thus preloaded by its own weight in the direction of the locking position 35.

[0039] At the second end 29, the locking element 25 is wider in an end region 26 than at the first end 27. The locking element 25 is T-shaped. In the example shown, the locking element 25 has a cap at the second end 28, which is plugged onto the end 28 of the locking element 25. Alternatively, the locking element 25 can also be formed integrally with the cap. On the underside 49 of the locking element 25, the latter has an actuating surface 32 in the end region 26. The locking element 25 can thus be actuated with the foot, namely brought from the locked position 35 into the open position 36.

[0040] On an upper side 48 of the locking element 25, it has a first display surface 30, which is visible from above when the locking element 25 is in the locked position 35. On a side connecting the upper and lower sides 48, 49 of the locking element 25, the locking element 25 has, in the end region 26, a second display surface 31, which is not visible from above when the locking element 25 is in the locked position 35, but is visible from above when the locking element 25 is in the open position 36.

[0041] In Fig. 2, the locking element 25 is in the locking position 35. The locking device 24 contains a holding mechanism 44, which is designed to hold the locking element 25 in the open position 36 when it has been brought into this position, and to release a movement of the locking element 25 when the coupling element 13 has been inserted into the receiving opening 37. The holding mechanism 44 is also designed to inhibit a movement of the locking element 25 from the locking position 36 into the open position 36. This can prevent the locking element 25 from moving unintentionally, for example due to accidental contact, towards the open position or the coupling element 13 from being pulled out of the receiving opening 37 due to tensile stress on the coupling device 12. The holding mechanism 44 is in Fig. 2 by a cover formed by the cover element 33. The holding mechanism 44 is covered with reference to the Fig. 3 to 6 are described in detail below.

[0042] The guide 17 has a guide base body in which a guide recess 19 is formed. The guide recess 19 extends at least substantially horizontally at a height such that the further coupling element 14 can be inserted into the guide recess 19. The further coupling element 14 extends horizontally, but transversely to the guide insertion direction 21 defined by the guide recess 19. The guide recess 19 also has a stop surface 20 whose contour is adapted to the outer contour of the further coupling element 14. When the further coupling element 14 is fully inserted into the guide recess 19, the stop surface 20 of the guide 17 forms a pivot bearing with a guide pivot axis 22 for the auxiliary device 11, around which the auxiliary device 11 can be pivoted upward.

[0043] In Fig. Figure 3 shows a schematic, side sectional view of the coupling device 12, in which the locking device 24 is in the locked position 35 and the coupling element 13 is inserted into the coupling receptacle 37 along the insertion direction 42. The locking element 25 is designed as a locking lever that extends between a first end 27 and a second end 29. At the first end 27, the locking element 25 is pivotally mounted about a pivot axis 28 (extending horizontally and transversely to the insertion direction 42). The locking element 25 can be pivoted between the locked position 35 and the open position 36. The center of gravity 50 of the locking element 25, at which the weight force 51 acts on the locking element 25, is arranged between the first end 27 and the second end 29.

[0044] On the underside 49 of the locking element 25, a locking projection 52 adjoins the locking recess 34. The locking projection 52 has a locking surface 56 and a guide surface 45. The guide surface 45 can, as in Fig. 3, be flat. The guide surface 45 is inclined in the insertion direction 42 and describes an acute angle 53 with the insertion direction 42 in the side projection. The acute angle 53 can be between 15° and 85°, preferably between 20° and 70°, more preferably between 30° and 60°, particularly preferably between 40° and 50°. The blocking surface 56 can also be flat. The blocking surface 56 is inclined in the extension direction 58, opposite to the insertion direction 42, and describes an obtuse angle 57 with the extension direction 58 in the side projection. The obtuse angle 57 can be between 95° and 175°, preferably between 100° and 150°, more preferably between 110° and 145°, particularly preferably between 120° and 130°. The blocking surface 56 can also be designed flat.

[0045] The guide surface 45 thus forms an (asymmetrical) wedge arrangement for the coupling element 13 with the wall in the opening area of ​​the receiving opening 37. The locking element 25 is pivotally pushed upwards by the coupling element 13 toward the open position 36 about the pivot axis 28 when the coupling element 13 is pushed into the receiving opening 37 in the insertion direction 42. The outer circumference of the coupling element 13 slides along the guide surface 45.

[0046] When the locking projection 52 is overcome by the coupling element 13, the receiving opening 37 is closed by the locking element 25—without any action by the user—by the weight force 51 acting on the locking element 25. The actuating surface 32 adjoins the guide surface 45 on the underside 49. The actuating surface 32 extends to the second end 29 of the locking element 25. The actuating surface 32 can also be flat.

[0047] On the upper side 48, the locking element 25 has the first display surface 30 in the second end region 29. This is located in the field of vision 46 of a user standing behind the wheelchair 10. The second display surface 31 is located in an area 47 outside the user's field of vision 46.

[0048] At the first end 27, the locking element 25 has a holding contour that functionally engages with a pawl 39 (spring-loaded against the holding contour), in particular a tip 40 of the pawl, of the holding mechanism 44. The holding contour has a holding projection 41 with a holding step 54 formed on a first flank of the holding projection 41 and a locking step 55 formed on a second flank of the holding projection 41. The holding step 54 and the locking steps 55 describe continuous, steady curves in the lateral projection. The holding step 54 serves to hold the locking element 25 in the open position 36 when it has been brought into the open position 36. The locking step 55 serves to inhibit movement of the locking element 25 from the locking position 35 toward the open position 36. The holding projection 41 is preferably designed asymmetrically. This means that the height of the holding level 54 differs from the height of the locking level 55.Preferably, the height of the holding step 54 is greater than the height of the locking step 55.

[0049] Fig. 4 to 6 show a schematic side section of an example of the coupling device 12 with the locking device 24.

[0050] The locking device 24 is in Fig. 4 in the open position 36. In this position 36, the receiving opening 37 is (fully) open in the side projection, so that the coupling element 13 can be inserted into the receiving opening 37 along an insertion direction 42.

[0051] The coupling element 13 is cylindrical. The inner contour of the receiving opening 37 in the base body 23 and the inner contour of the locking recess 34 in the locking element 25 of the coupling element receptacle 16 are adapted to the outer contour of the coupling element 13. For example, both inner contours each form a semicircular section in the lateral projection, so that the two complement each other in the lateral projection to form a circular section, which at least partially encloses the coupling element 13 in the lateral projection when the locking element 25 is in the locking position 35, as in Fig. 5 shown.

[0052] The holding mechanism 44 of the locking device 24 is in the Fig. 4 to 6. The latch 39 is spring-loaded such that the tip 40 of the latch 39 engages the retaining step 54 of the retaining projection 41. The retaining mechanism 44 thus holds the locking element 25 in the open position 36 when it has been brought into the open position 36. The retaining mechanism 44 is covered by the cover element 33, which forms the cover, wherein the cover element 33 forms an abutment for the spring element 43 of the latch 39 of the retaining mechanism 44. The spring element 43 can be a compression spring.

[0053] In the end region at the first end 27 of the locking element 25, a projection with a surface 38 adjoins the locking recess 34 of the locking element, which projection projects into the receiving opening 37 of the base body 23 in the lateral projection when the locking element 25 is in the open position 36.

[0054] Fig. 5 shows the coupling device 12 with the locking device 24 in a position in which the coupling element 13 has been (completely) inserted into the receiving opening 37 of the base body 23.

[0055] In this position, the projection with the surface 38 of the locking element 25 has been displaced by the coupling element 13 such that the pawl 39 no longer engages with the retaining projection 41 formed on the locking element 25. This means that the retaining step 54 of the retaining contour has been overcome by the tip 40 of the pawl 39. The locking element 25 is thus no longer held in the open position 36 by the retaining mechanism 44. The locking element 25 falls under its own weight toward the locking position 35.

[0056] In Fig. 6, the locking device 24 is shown in the locked position 35, with the coupling element 13 located in the receiving opening 37. In the locked position 35, the pawl 39 is in engagement (spring-loaded) with the locking step 55 of the holding projection 41 of the holding contour. The holding mechanism 44 is designed to inhibit movement from the locked position 35 towards the open position 36. In addition, a force acts on the locking element 25 in the direction of the locked position 35 when the coupling element 13 is subjected to a tensile load. The coupling element 13 is pulled under tensile load against the locking surface 56, which is inclined opposite to the extension direction 58. Because the locking surface forms an obtuse angle 57 with the wall in the opening region of the receiving opening 37, the locking element 25 is subjected to a downward force, whereby it is held in the locked position 35.

[0057] The coupling device 12 described so far can be connected as follows:

[0058] The locking element 25 can be in the open position 36 for coupling, as in Fig. 7. This coupling process is shown in the Fig. 7 to 9. For example, the locking element 25 is first brought into the open position 36 with the foot, in which the receiving opening 37 of the coupling element receptacle 16 is open and the locking element 25 is held by the holding mechanism 44. The auxiliary device 11 is preferably connected to the wheelchair 10 by a button movement.

[0059] The auxiliary device 11 is now tilted such that the additional coupling element 14 is at the level of the guide recess 19 of the guide 17. The guide recess 19 of the guide 17 extends at least substantially horizontally and is open obliquely downwards, thus facilitating the threading of the additional coupling element 14 into the guide recess 19. The guide 17, together with the additional coupling element 14, forms a sliding joint when the additional coupling element 14 is threaded into the guide 17.

[0060] The auxiliary device 11 can then be pushed into the guide insertion direction 21, as shown in Fig. 8, so that the further coupling element 14 is located in the guide 17. When the further coupling element 14 is pushed to the stop defined by the stop surface 20, preferably at least part of the peripheral surface of the further coupling element 14 is in contact with the stop surface 20 of the guide 17.

[0061] The auxiliary device 11 can now be pivoted upwards around the guide pivot axis 22 of the guide 17, as shown in Fig. 8. The coupling element 13 is inserted diagonally from below into the receiving opening 37 of the coupling element receptacle 16. The receiving opening 37 of the base body 23 of the coupling element receptacle 16 is correspondingly opened diagonally downwards. When the coupling element 13 is at least partially located in the receiving opening 37, the movement release of the holding mechanism 44 is triggered by the coupling element 13 touching the projection on the surface 38. The locking element 25 is now no longer held by the holding mechanism 44 in the open position 36, so that it falls into the locking position 35 under its own weight, whereby the coupling element 13 is locked in the coupling element receptacle 16, as shown in Fig. 9. The auxiliary device 11 is now detachably connected to the wheelchair 10. To release it, the locking element 24 can be pivoted upward into the open position 36, for example, with the foot. The user can detach the auxiliary device 11 from the wheelchair 10 without having to bend down.

[0062] Alternatively, the locking element 25 can also be in the locking position 35 for coupling, without it being necessary to first bring the locking element 25 into the open position 36, as in Fig. 10. This coupling process is described in the Fig. 10 to 12 shown.

[0063] The auxiliary device 11 can now be tilted again so that the further coupling element 14 is at the height of the guide recess 19 of the guide 17, and pushed in the guide insertion direction 21 so that the further coupling element 14 is located in the guide 17. The auxiliary device 11 can now be pivoted upwards around the guide pivot axis 22, as shown in Fig. 11 is shown.

[0064] In Fig. 11, the locking element 25 is pushed upwards by the coupling element 13, which slides along the guide surface 45 of the locking element 25, against the weight of the locking element 25 acting on the locking element 25. The locking element 25 thereby pivots about the pivot axis 28 at least until the coupling element 25 is pushed past the locking projection of the locking element 25 into the receiving opening 37 in the base body 23 and the weight acting on the locking element 25 closes the receiving opening 37 behind the coupling element 13, as in Fig. 12 is shown.

[0065] The coupling device 12 described so far can be uncoupled as follows:

[0066] To decouple the coupling element 13 from the coupling element receptacle 16, the locking element 25 can be brought into the open position 36, in which the receiving opening 37 of the coupling element receptacle 16 is open, for example by pivoting the locking element 25 upwards about the pivot axis 28 with the top of the foot or the top of the toes. By pivoting the locking element 25 upwards, the coupling element 13 is displaced from the surface 38 of the projection, which protrudes into the receiving opening 34 at least in the lateral projection in the open position 35. The coupling element 13 is thus pushed out of the receiving opening 34. When the locking element 25 is in the open position 36, it is held in the open position 36 by the holding mechanism 44. For further decoupling, the auxiliary device 11 can now be pivoted downwards about the guide pivot axis 22.Subsequently, the further coupling element 14 can be moved out of the guide 17 so that the auxiliary device 11 is completely decoupled from the wheelchair 10.

[0067] The invention relates to a coupling device 12 for detachably connecting an auxiliary device 11 to a wheelchair 10, comprising a coupling element 13 and a coupling element receptacle 16. The coupling element receptacle 16 opens a base body 23 and a locking device 24, wherein the locking device 24 is provided with a holding mechanism 44 that holds a locking element 25 in an open position 36. As soon as the coupling element 13 has been inserted into the receptacle opening 37, the holding mechanism 44 releases the movement of the locking element 25, which, driven by its own weight, falls into the locked position 35 and thus encloses the coupling element 13 in the receptacle opening 37. The locking device 24 is designed as a locking latch by the holding mechanism 44, the locking element 25 of which closes automatically, in particular due to its own weight, when the coupling element 13 has been at least partially inserted into the receptacle opening 37 of the base body 23. Reference symbol: 10 wheelchairs 11 Auxiliary device (stair climbing aid) 12 coupling device 13 coupling element (coupling bolt) 14 additional coupling element 15 Page of the auxiliary facility 16 coupling element holder 17 Guide 18 Mounting plate 19 Guide recess 20 stop surface 21 Guide insertion direction 22 Guide swivel axis 23 Base body of the coupling element holder 24 locking device 25 Locking element (locking lever) 26 End area of ​​the locking element 27 first end of the locking element 28 Swivel axis 29 second end of the locking element 30 first display area 31 second display area 32 operating surface 33 Cover (cover element) 34 Locking recess 35 Locking position 36 Open position 37 Receiving opening of the base body 38 Surface of a projection on the locking element 39 jack 40 jack tip 41 Holding projection 42 Insertion direction 43 Spring element 44 Holding mechanism 45 Guide surface 46 Field of vision of a user 47 Area outside the field of view 48 Top of the locking element 49 Underside of the locking element 50 Center of gravity of the locking element 51 Weight 52 locking projection 53 acute angle 54 holding level 55 blocking level 56 restricted area 57 obtuse angle 58 Extension direction QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2005 008 826 B3 [0003, 0016] EP 3 439 604 B1

[0006] DE 20 2018 002 476 U1

[0007] EP 3 622 930 A2

[0008]

Claims

[1] Coupling device (12) for detachably connecting an auxiliary device (11) to a wheelchair (10), with a coupling element (13) and a coupling element receptacle (16), which has the following: - a base body (23) in which a receiving opening (37) for receiving the coupling element (13) is formed; - a locking device (24) having a locking element (25) which is preloaded and movable in the direction of the locking position (35) between an open position (36), in which the coupling element (13) can be inserted into and removed from the receiving opening (37), and a locking position (35), in which the coupling element (13) is held in the receiving opening (37) by the locking element (25), wherein the locking device (24) has a holding mechanism (44) which is designed to hold the locking element (25) in the open position (36) when it has been brought into the open position (36), and to release a movement of the locking element (24) in the direction of the locking position (35) when the coupling element (13) has been at least partially inserted into the receiving opening (37). [2] Coupling device (12) according to claim 1, characterized by that the release of the locking element (25) by the holding mechanism (44) can be triggered by means of the coupling element (13). [3] Coupling device (12) according to claim 1 or 2, characterized by that the locking device (26) has a cover element (33) in which the functional parts of the holding mechanism (44) are accommodated. [4] Coupling device (12) according to one of the preceding claims, characterized by that the locking device (24) has a pivot axis (28) about which the locking element (25) can be pivoted between the open position (36) and the locked position (35). [5] Coupling device (12) according to claim 4, characterized by that the pivot axis (28) of the locking device (24) is arranged above and / or behind the receiving opening (37) of the base body (23). [6] Coupling device (12) according to one of the preceding claims, characterized by that the blocking element (25) is arranged in the blocking position (35) such that the receiving opening (37) of the base body (23) is closed in a lateral projection. [7] Coupling device (12) according to one of the preceding claims, characterized by that the blocking element (25) has a blocking recess (34) whose inner contour is at least partially adapted to the outer contour of the coupling element (13), which is preferably open towards an underside (49) of the blocking element (25). [8] Coupling device (12) according to claim 7, characterized by that a locking projection (52) adjoins the locking recess (34), which forms a guide surface (45) on a side facing away from the locking recess (34), which is inclined in the insertion direction (42), wherein the guide surface (45) preferably describes an acute angle (53) with the insertion direction (42) in the lateral projection. [9] Coupling device (12) according to one of the preceding claims, characterized bythat the locking element (25) is elongated between a first end (27) and a second end (29), wherein the locking element (25) is pivotally mounted at the first end (27) about the pivot axis (28) from the open position (36) into the locked position (35) and vice versa. [10] Coupling device (12) according to one of the preceding claims, characterized by that the locking element (25) is preloaded by its own weight in the direction of the locking position (35). [11] Coupling device (12) according to one of the preceding claims, characterized by that the locking element (25) has on its underside (49) an actuating surface (32) on which it can be actuated with the foot, preferably with the tip of the foot, ie can be brought from the locking position (35) into the open position (36). [12] Coupling device (12) according to one of the preceding claims, characterized byin that the blocking element (25) has a first display surface (30) and a second display surface (31), wherein the first display surface (30) is only visible when the blocking element (25) is in the blocking position (35), and the second display surface (31) is only visible when the blocking element (25) is in the open position (36). [13] Coupling device (12) according to one of the preceding claims, characterized by that the holding mechanism (44) comprises a pawl (39) which engages with a holding projection (41) formed on the locking element (25) when the locking element (25) is in the open position (36). [14] Coupling device (12) according to one of the preceding claims, characterized bythat a projection with a surface (38) is formed on the blocking element (25) which projects in a lateral projection into the receiving opening (37) of the base body (23) when the blocking element (25) is in the open position (36). [15] Coupling device (12) according to one of the preceding claims, characterized by that the base body (23) with the locking device (26) mounted thereon can be mounted on the wheelchair (10) in a height-adjustable manner. [16] Wheelchair (10) with a coupling device (12) according to one of the preceding claims and an auxiliary device (11), wherein the coupling element (13) is preferably fastened to the auxiliary device (11) and the coupling element receptacle (16) is fastened to the wheelchair (10).

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