Electric motor auxiliary or retrofit drive

Abstract

Electric motor auxiliary or retrofit drive for self-stabilizing moving vehicles, in particular mobility aids for people with reduced mobility, such as wheelchairs or walkers, and pushed or pulled transport trolleys for goods transport, such as platform trolleys, transport carts, - with a platform that forms a standing surface for a person operating the vehicle, - with a coupling component on the platform, which is designed to connect the platform to the vehicle, - with at least one drive wheel located at the end of the platform furthest from the coupling component, - with an electric motor drive for the drive wheel, - with a support as part of the coupling device, which is connected to the platform via a first linkage device and to the vehicle via a second linkage device, - wherein the platform is designed to be positioned between a forward-facing position and a rear-facing position, characterized by the fact that - the carrier provides two movement paths - the first linkage device is movable along a first path of movement and the second linkage device is movable along the second path of movement in order to move the platform between a position located at the front in the direction of travel and a position located at the rear in the direction of travel.

Description

[0001] The invention relates to an electric motor auxiliary or retrofit drive for self-stabilizing moving vehicles, in particular mobility aids for persons with reduced mobility, such as wheelchairs or rollators, and pushed or pulled transport trolleys for goods transport, such as platform trolleys, transport carts, - with a platform that forms a standing surface for a person operating the vehicle, - with a coupling component on the platform, which is designed to connect the platform to the vehicle, - with at least one drive wheel located at the end of the platform furthest from the coupling component, - with an electric motor drive for the drive wheel, - with a support as part of the coupling device, which is connected to the platform via a first linkage device and to the vehicle via a second linkage device, - wherein the platform is designed to be positioned between a forward-facing position and a rear-facing position.

[0002] Self-stabilizing vehicles within the meaning of this invention are constructions in which a frame undercarriage is equipped with wheels for propulsion. Their inherent stability is achieved through their design. Self-stabilizing vehicles within the meaning of this invention are considered to be those that remain stable in their operating position without tipping over, without any special assistance from the user. Such inherent stability can be achieved by the vehicle itself, for example, by being equipped with three wheels, thus enabling it to stand and move independently. However, it is also conceivable that the inherent stability is achieved by coupling an electric auxiliary drive.

[0003] A generic electric motor auxiliary or retrofit drive is shown, for example, in DE 20 2024 106 280 U1 of the applicant. Here, a wheelchair that is usually manually operated is converted into an electrically movable wheelchair by the retrofit drive, whereby the retrofit drive, when it follows behind the wheelchair, offers the possibility of additional passenger transport on its platform.

[0004] This publication also shows the possibility of positioning the retrofit drive in an alternative location beneath the wheelchair. In this position, the retrofit drive is used exclusively to move the wheelchair. Transporting another person is not possible in this position.

[0005] A retrofit drive is also shown in the applicant's own patent application DE 10 2017 127 568 B3. Here, the retrofit drive serves to propel a rollator electrically. The rollator user can stand on the auxiliary drive and does not have to walk.

[0006] Finally, WO 2024 / 017441 A1 illustrates, using the example of a stroller, a trailing platform that allows the user to stand on it and be propelled by an electric motor with the stroller. This platform is designed to be slid along a groove under the stroller.

[0007] The arrangement of a generic auxiliary or retrofit drive in either two positions behind or underneath the vehicle is quite advantageous. In the case of the applicant's own wheelchair, the trailing position allows a person to ride along while the wheelchair is simultaneously powered by an electric motor.

[0008] The auxiliary or retrofit drive system, located beneath the wheelchair, allows the user to propel the electrically powered wheelchair independently, or, as an auxiliary drive, enables a caregiver to provide additional control. This relieves the caregiver of some of the strain, as they do not need to exert their full strength to move the wheelchair. This can be helpful when going uphill or – in which case the drive acts as an auxiliary brake – when going downhill. It also simplifies wheelchair assistance, particularly for caregivers who, due to age or other limitations, are unable to assist the wheelchair user without the auxiliary drive.

[0009] However, it has also become apparent that the solutions known in the prior art for the alternative arrangement of the auxiliary drive in relation to the vehicle are perhaps inflexible. The more compact the vehicle's design, the more difficult it is to ensure a correct position for both the trailing arm and the mounting of the auxiliary or retrofit drive. Furthermore, user-specific requirements for convenient positioning of the auxiliary or retrofit drive, particularly for the accompanying person or assistant, cannot be met with the systems of the prior art.

[0010] The object of the invention is therefore to provide an auxiliary or retrofit drive that can be handled more flexibly.

[0011] The problem is solved by an electric motor auxiliary or retrofit drive with the features of claim 1, in particular with its characterizing features, according to which - the carrier provides two movement paths - the first linkage device is movable along a first path of movement and the second linkage device is movable along the second path of movement in order to move the platform between a position located at the front in the direction of travel and a position located at the rear in the direction of travel.

[0012] The use of the inventive support with its two paths of movement makes it possible to utilize the support's length twice for movement of the steering devices and thus for movement of the platform in the direction of travel of the retrofitted vehicle, provided that two independent steering devices are simultaneously arranged on the support. In this way, a greater path of movement can be achieved with the available support length. Alternatively, a specific path of movement can be ensured with a shorter support.

[0013] For example, the auxiliary or retrofit drive according to the invention can be built more compactly or, with the same design, used on vehicles in which a greater displacement path is allowed between the two intended front or rear end positions.

[0014] To simplify operation and construction, the invention provides that the coupling component has a common locking device for the first and second linkage devices.

[0015] The common locking device allows either one or both linkages to be selectively locked or unlocked in their respective end positions simultaneously. This ensures that when the common locking device is actuated, both linkages can be controlled for the correct positioning of the auxiliary or retrofit drive.

[0016] Therefore, it is specifically planned that the locking device - in a first position both linkage devices are locked in their maximum distances from each other end positions, - in a second position, one of the linkage devices is released for movement along the carrier, - in a third position, releases both linkage devices for movement along the carrier.

[0017] In a preferred embodiment, it is proposed that one or both linkage devices are provided with a stop component which allows the linkage device to be fixed in an intermediate position between the end positions defined by the locking device.

[0018] With the additional stop component, it is possible to fix one or both pivot points in intermediate positions, so that when moving or shifting the auxiliary or retrofit drive along the vehicle's direction of travel, not only the respective end positions are available as defined positions. This allows the platform's position to be adapted to individually required conditions. For example, when used with a wheelchair, the trailing platform can be set not only in its maximum possible disengagement position. If the physique of the person standing on the platform of the auxiliary or retrofit drive requires it, the platform can be locked in a different position, for example, closer to the wheelchair.

[0019] When used on a stroller, it is conceivable to use the stop component to provide a less trailing position of the platform, so that in addition to the accompanying person on foot, another person, for example a child, can stand up on the platform without restricting the handling of the stroller by an accompanying adult.

[0020] A particularly advantageous design is characterized by the fact that - the support is a double-T beam, which forms a path of movement for a steering device on both its upper and lower sides, - each linkage device has a slide which slides on the outwardly facing surface of the respective associated T-profile, each slide being provided with two opposing jaws which grip the T-profile.

[0021] Furthermore, it is specifically provided that the locking device includes a locking lever which is arranged at one end of the carrier and that a pivot axis connected to the locking lever is mounted inside the carrier, which exits at the end of the carrier opposite the locking lever.

[0022] It is also planned that - the axle has a locking disc at each end and each locking disc is coupled to the axle's movement, - each slide has a locking profile associated with its assigned locking disc, - the respective locking disc engages in the assigned locking profile depending on the position of the locking lever to fix the assigned position of the slide, or is out of engagement to release the assigned slide.

[0023] In a specific embodiment, it is proposed that the carrier has a detent profile, such as detent bores or detent grooves, and that the stop component is a detent pin, wherein the detent pin interacts with the detent profile to anchor the slide in an intermediate position.

[0024] Further advantages of the invention and a better understanding will become apparent from the following description of an exemplary embodiment. The following are shown: Fig. 1 an auxiliary or retrofit drive according to the invention in trailing use on a wheelchair shown only schematically, Fig. 2 the representation according to Fig. 1 with an auxiliary or retrofit drive arranged in the underfloor installation on the wheelchair, Fig. 3 the representation according Fig. 1 with an auxiliary or retrofit drive in storage position, Fig. 4 the coupling component of the auxiliary or retrofit drive according to the invention in perspective view, Fig. 5 the view to look after Fig. 4 as an exploded view, Fig. 6 the coupling component after Fig. 4 in side view, Fig. 7 the coupling component according to Fig. 4 in top view, Fig. 8 the coupling component in longitudinal section view according to section line AA in Fig. 7, Fig. 9 a cross-section through the coupling component according to section line BB in Fig. 7, Fig. 10 a cross-section through the coupling component according to section line CC in Fig. 7, Fig. 11 a view of the locking lever of the locking device of the coupling component in the locked position, Fig. 12 a view of the locking lever of the locking device of the coupling component in a first release position, Fig. 13 a view of the locking lever of the locking device of the coupling component in a second release position, Fig. 14 a view of the locking disc located next to the locking lever in the locked position, Fig. 15 a view of the locking disc according to Fig. 14 in a first solution position, Fig. 16 a view of the locking disc according to Fig. 14 in a second solution position.

[0025] In the figures, an auxiliary or retrofit drive according to the invention – hereinafter also referred to simply as the drive – is provided with a reference numeral 10. Fig. Figure 1 shows the drive 10 together with a schematically represented wheelchair 11. The representation of the wheelchair 11 is limited to the seat 12 with the attached hand grips 13, a schematically represented rear wheel 14 and a schematically represented front wheel 15, as well as the indicated scissor linkage 16, to which the drive 10 is attached in a manner to be described later.

[0026] Instead of a wheelchair, the drive unit 10 can also be coupled to other self-stabilizing vehicles. For the purposes of this invention, self-stabilizing vehicles are defined as all vehicles that are in equilibrium without user intervention, i.e., they do not tip over when the user moves them. Typically, such a vehicle will have at least three wheels, or—if it is only two-wheeled—it will gain its self-stabilization by being attached to the drive unit 10.

[0027] In addition to wheelchairs 11, the invention is aimed at other mobility aids for persons with reduced mobility, or in particular at pushed or pulled transport vehicles for primarily internal goods transport, such as platform trolleys or transport carts, but also shopping carts. The drive 10 can also be used on strollers or small vehicles, such as mail delivery carts. All these vehicles are ones that—if used without the drive 10 according to the invention—must be moved manually by a person and otherwise have no self-propulsion.

[0028] The in Fig. The drive unit 10, as depicted in its entirety, has a platform 17 that forms a housing 18 in which technical components such as energy storage, control, etc., can be arranged. The platform 17 then forms at least a standing surface 19 on which a person operating the unit can stand.

[0029] The platform 17 is attached to the vehicle, in this case the wheelchair 11, via a coupling component 20, which will be discussed in detail later. The coupling component 20 is hinged at the front end of the platform 17, the end facing the vehicle (i.e., the wheelchair 11), where at least one drive wheel 21 is located. In this embodiment, two drive wheels 21 arranged side by side are used. The drive wheel 21 is therefore located at the end of the platform 17 furthest from the coupling component 20.

[0030] The vehicle – here, wheelchair 11 – moves forward in direction X, so that subsequent directional terms refer to the direction X shown in the drawings. It should be noted that a reverse direction of travel does not change the fundamental description and functionality, but merely reverses terms like "front" or "back".

[0031] As will be described later, the coupling component serves not only to position platform 10 on the wheelchair 11 – which here represents any vehicle. Platform 17 can also be positioned along the coupling component and relative to the wheelchair 11 at least between a position located at the rear in the direction of travel X – i.e., trailing – and a position located at the front in the direction of travel – i.e., under the vehicle in an underfloor position. The trailing position of platform 17, located at the rear in the direction of travel, is described in Fig. 1 shown. Fig. Figure 2, however, shows the platform 17 in its forward position in the direction of travel, which in the case of a wheelchair 11 corresponds to the underfloor arrangement, i.e. an arrangement under the wheelchair 11.

[0032] Finally, it shows Fig. 3. A storage position of the platform 17 that is only marginally relevant to the invention. In this position, the platform 17 is folded up and its drive wheel 21 is located behind the backrest of the seat 12. The drive wheel 21 is therefore no longer in contact with the ground, so the drive 10 cannot perform its function. This can be useful, for example, if an assistant is accompanying the wheelchair user and does not want to be transported on the platform 17. The platform 17 can also assume this position if, for example, the energy storage for the drive 10 is empty and the drive 10 is therefore inoperative.

[0033] In Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10, Fig. 11, Fig. 12, Fig. 13, Fig. 14, Fig. 15 to Fig. 16 now discusses the structure and function of the coupling component 20, which is essential for the invention.

[0034] Fig. Figure 4 shows the coupling component 20 in its entirety in a perspective view. The coupling component 20 initially comprises a support 22, on which a first linkage device 23 and a second linkage device 24 are arranged.

[0035] The first linkage 23 comprises a first slide 25, which is coupled to platform 17 via a first linkage rod 26. The first linkage 23 thus serves to connect the coupling component 22 and the platform 17. The second linkage 24 has a second slide 27, which carries a second linkage rod 28. A coupling clamp 29 is mounted on the second linkage rod 28, by means of which the coupling component 20 is fixed to the wheelchair 11 in the area of ​​the scissor linkage 16, as can be seen, for example, in Fig. 1 can be seen. Finally, the second slide 27 carries a stop component 30 in the form of a locking pin 30, which will be discussed later.

[0036] The carrier 22 is provided with a locking profile 31 in the form of a single locking bore, which interacts with the locking pin 30. Finally, the coupling component 20 carries a locking device 32, which includes the clearly visible locking lever 33 and other components to be described below.

[0037] The coupling component 20 can be viewed in more detail using the exploded view in Fig. 5. Explain. The first slide 25 of the first linkage device 23 consists of a first sliding body 34, which rests on a first path of movement 35 of the beam 22, which is constructed as a double-T beam. Two first jaws 36, located on the respective outer sides of the first sliding body 34, engage the first T-profile 37 forming the first path of movement 35. In this way, the first slide 27 is fixed to the beam 22. The engagement of the first T-profile 37 by the first jaws 36 is shown in the sectional views according to... Fig. 9 and Fig. 10 is evident.

[0038] The first sliding body 34 has a front locking profile 38 and a rear locking profile 39. Both interact with the locking device 32 in a manner to be described later.

[0039] The second, upper T-profile 40 of the support 22 forms the second movement track 41 on its upper surface. The second sliding element 46 of the second carriage 27 rests on the second movement track 42, its second jaws 42 resting on the right and left sides of the second carriage 27 and engaging the second T-profile 40. In this way, the second carriage 27 is slidably fixed on the support 22, analogous to the first carriage 25. This is shown by the Fig. 9 and Fig. 10. The second sliding body 46 forms a third locking profile 47, which interacts with the locking device 32.

[0040] Based on the in Fig. In the exploded view of the coupling component 20 shown in Figure 5, the locking device 32 can also be seen in its individual parts. For this purpose, the support 22 was shown separated and pulled apart in the drawing. This illustrates that a pivot axis 44 is mounted within a tubular cavity 43 of the support 22. However, the invention actually provides for an undivided, continuous support 22. The pivot axis 44 connects a first locking disk 45, which is associated with the first slide 25 and, in particular, with its two locking profiles 38 and 39.

[0041] At its end opposite the first locking disc 45, the pivot axis 44 carries a second locking disc 48. The second locking disc 48 is associated with the second sliding body 46 and, in particular, its third locking profile 47. The aforementioned locking lever 33 is fixed to the first locking disc 45.

[0042] The pivot axis 44 with the locking discs 48 and 45 and the locking lever 33 form the essential components of the locking device 32. By means of the locking lever 33, the locking discs 45, 48 can be moved from a locked position, in which the slides 25 and 27 are fixed in their respective end positions, to two different open positions, in which one of the two slides 25, 27 or both slides 25, 27 are freely movable on the carrier 22.

[0043] Fig. Figure 6 shows the coupling component 20 in a side view. The first slide 25 is in its first end position, located at the rear in the direction of travel of the wheelchair 11. The vertically positioned locking lever 33 holds the first locking disc 45 in its closed position. In this closed position, the locking disc engages in the front locking profile 38 of the first slide 25. In this way, the first slide 25 is securely fixed in its end position, located at the rear in the direction of travel X.

[0044] The second sled, number 27, takes on a role in Fig. 6 also reaches its first end position. However, this first end position of the second slide 27 is at the end of the carrier 22 facing away from the first slide 25, i.e., at the end of the carrier that is at the front in the direction of travel X. Here, too, the associated second locking disc 48 is in its closed or locked position when the lever 33 is vertical. In this locked position, the locking disc 48 engages in the third locking profile 47 of the second slide 27 and holds it in its end position that is at the front in the direction of travel X.

[0045] If sleds 25 and 27 the Fig. In the 6 positions shown, platform 17 is in its rear position relative to wheelchair 11, i.e. trailing position.

[0046] Fig. Figure 7 shows the coupling component 20 in a top view. This representation corresponds, as far as the position of the first slide 25 and the second slide 27 is concerned, to the Fig. 6. The representation according to Fig. Figure 7 serves in particular to clarify the section lines of section views 9 and 10.

[0047] Fig. Figure 8 shows the coupling component 20 in a sectional view along section line AA. Fig. 7. Here too, the first sled or the second sled is located in the... Fig. 6 already described, respective final positions. Fig. Figure 8 shows in particular how the pivot axis 44 is seated in the tubular cavity 43 of the carrier 22 and connects the first locking disc 45 to the second locking disc 48 in a movement-coupled manner. It can also be seen that both the first locking disc 45 and the second locking disc 48 are located in the respective Fig. The front locking profile 38 or the third locking profile 47 described in section 6 is inserted, thus fixing the slide 25 or the slide 27 in its respective position.

[0048] The function of the locking device 42 is now described as follows: Fig. Figure 11 shows a view of the coupling component 20 in the direction of travel X towards the lever 33. This is in its vertical position, which defines the locking position. In this locking position, both slides 25 and 27 are in their respective positions. Fig. The end position shown in Figure 6 is fixed. This is achieved by the first locking disc 45 engaging in the front locking profile 38 of the slide 25.

[0049] Fig. 14 corresponds to Fig. 11. At Fig. Figure 14 shows a view opposite to the direction of travel X of the coupling component 20. Here, the view focuses on the locking disc 48. The second locking disc 28 engages in the third locking profile 47 of the second slide 27 and holds it in its forward end position in the direction of travel X.

[0050] Fig. Figure 12 shows the coupling component 20 again in view in the direction of travel X towards the second locking disc 45. The view after Fig. 12 therefore essentially corresponds to the view Fig. 11. In Fig. However, in step 12, the locking lever 33 is moved into its first release position. For this purpose, it was pivoted approximately 45° clockwise. The first locking disc 45 still engages in a locking manner with the front locking profile 38 of the first slide 25, so that it continues to move in its rear end position in the direction of travel X. Fig. 6 is located.

[0051] Fig. 15 corresponds to Fig. 12. However, here again a view opposite the direction of travel X is shown of the coupling component 20. This is therefore a view of the second locking disc 48 and thus a representation analogous to Fig. 14. In the Fig. In the first release position of the locking lever 33 shown in Figure 15, the second locking disc 48 is in the open position. As Fig. As shown in Figure 15, the second locking disc 48 no longer engages in the third locking profile 47 of the second slide 27. Thus, the second slide 27 can be moved relative to the support 22, or, in the illustrated embodiment, the support 22 is actually moved relative to the second slide 27, since the second slide 27 is fixed to the vehicle, here the wheelchair 11.

[0052] The relative displacement of the carrier 22 together with the first sled 25 comes to an end when the in Fig. 6a The second slide has reached the position on the carrier 22. In this position, the stop component – ​​in this specific embodiment, the locking pin 30 – engages in the locking bore 31 of the carrier 22. In this way, the slide 27 is locked onto the carrier 22.

[0053] Fig. 13 is again a view of the coupling component 20 in the direction of travel X, thus analogous to Fig. 11. Here, the locking lever 33 is in its second release position, in which it has been pivoted 90° clockwise. This releases the engagement of the first locking disc 45 with the front locking profile 38 of the first slide 25. The first slide 25 is now slidable along the carrier 22. It can now be moved to the end of the carrier 22 that is closest to the front in the direction of travel X.

[0054] Fig. Figure 16 shows the corresponding view against the direction of travel X of the coupling component 20, again showing the second locking disc 48. In the present embodiment, it is visible that the second slide 27 is also free in the second release position of the locking lever 33. The second locking disc 48 does not engage with the third locking profile.

[0055] However, an alternative embodiment of the second locking disc 48 is also conceivable, which, due to a different geometry, engages in the third locking profile 47 in the second release position of the lever 33 and thus secures the slide 27 in its forward position in the direction of travel X (see Fig. 6) holds.

[0056] Fig. Figure 16 also shows that the locking disc 48 has no overlap or engagement with the front locking profile 38 of the second slide 25, so that the latter can be pushed along the profile 22 in the direction of travel X until its rear locking profile 39 comes into a possible engagement position with the second locking disc 48.

[0057] Fig. Figure 6b shows the position of both slides in their respective second end positions. In the specific embodiment shown, the second slide 27 is secured near the rear end of the carrier 22 in the direction of travel X by the engagement of the stop component 30 in the locking profile 31, whereas the first slide 25 is fixed at the front end of the carrier 22 in the direction of travel X by the locking lever 33, which is again in a vertical, locked position.

[0058] Then the second locking disc 48 engages in the rear locking profile 39 of the first slide 25. The position according to Fig. 6b takes over the platform when it is in the Fig. 2 is located in the underfloor arrangement shown under the vehicle or under the wheelchair 11.

[0059] In a further described embodiment, not shown in the illustration, it is conceivable that the locking profile 31 along the carrier 22 consists of several locking bores arranged one behind the other in the direction of travel X. Consequently, the second carriage could then be fixed in a multitude of positions along the carrier 22. Depending on the distance between the locking bores 31, a very granular distance adjustment of the trailing platform 17 relative to the vehicle, here the wheelchair 11, can be made. In this way, the distance of the trailing platform 17 can be adjusted to the height and / or posture of an attendant standing on the platform.

[0060] Not shown in the drawings, but readily conceivable, is an embodiment of the invention in which the locking device 32 is switched by means of a Bowden cable or an actuator, which may also be electrically driven, in addition to or as an alternative to the locking lever 33. In this way, people with limited mobility do not need to bend down to switch the locking device 32. The same applies to the stop component 30. Additionally, the drive 10 or the platform 17 can be moved between the different positions by motor. For this purpose, the locking device 32 and / or the stop component 30 is switched accordingly, and then the motorized drive of the platform 17 is used to move the platform 17 forward or backward into the desired position. Reference symbol list 10 Auxiliary or retrofit drive / drive 11 wheelchair 12 seats 13 Handle 14 rear wheel 15 front wheel 16 scissor arms 17 Platform 18 cases 19 Standing area 20 coupling component 21 Drive wheel 22 carriers 23 first linkage device 24 second linkage device 25 first sled 26 first linkage rod 27 second sled 28 second linkage rod 29 coupling clamps 30 Stop component / locking pin 31 Detent profile / detent bore 32 Locking device 33 locking levers 34 first sliding body 35 first movement path 36 first bakes 37 first T-profile 38 front locking profile 39 rear locking profile 40 second T-profile 41 second movement path 42 second cheeks 43 tubular cavity 44 axis of rotation 45 first locking disc 46 second sliding body 47 third locking profile 48 second locking disc QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] DE 20 2024 106 280 U1

[0003] DE 10 2017 127 568 B3

[0005] WO 2024 / 017441 A1

[0006]

Claims

[1] Electric motor auxiliary or retrofit drive for self-stabilizing moving vehicles, in particular mobility aids for persons with reduced mobility, such as wheelchairs or walkers and pushed or pulled transport trolleys for goods transport, such as platform trolleys, transport carts, - with a platform that forms a standing surface for a person operating the vehicle, - with a coupling component on the platform, which is designed to connect the platform to the vehicle, - with at least one drive wheel located at the end of the platform furthest from the coupling component, - with an electric motor drive for the drive wheel, - with a support as part of the coupling device, which is connected to the platform via a first linkage device and to the vehicle via a second linkage device, - wherein the platform is designed to be positioned between a forward-facing position and a rear-facing position, characterized by , that - the carrier provides two movement paths - the first linkage device is movable along a first path of movement and the second linkage device is movable along the second path of movement in order to move the platform between a position located at the front in the direction of travel and a position located at the rear in the direction of travel. [2] Electric motor safe auxiliary or retrofit drive according to claim 1, characterized by that the coupling component has a common locking device for the first and second linkage devices. [3] Electric motor auxiliary or retrofit drive according to claim 2, characterized by that the locking device - in a first position both linkage devices are locked in their maximum distances from each other end positions, - in a second position, one of the linkage devices is released for movement along the carrier, - in a third position, releases both linkage devices for movement along the carrier. [4] Electric motor auxiliary or retrofit drive according to claim 2 or 3, characterized by that one or both linkage devices are provided with a stop component which allows the linkage device to be fixed in an intermediate position between the end positions defined by the locking device. [5] Electric motor auxiliary or retrofit drive according to any of the preceding claims, characterized by , that - the support is a double-T beam, which forms a path of movement for a steering device on both its upper and lower sides, - each linkage device has a slide which slides on the outwardly facing surface of the respective associated T-profile, each slide being provided with two opposing jaws which grip the T-profile. [6] Electric motor auxiliary and retrofit drive according to claim 2, characterized by that the locking device comprises a locking lever which is arranged at one end of the carrier and within the carrier a pivot axis connected to the locking lever is mounted, which exits at the end of the carrier opposite the locking lever. [7] Electric motor auxiliary and retrofit drive according to claims 3, 5 and 6, characterized by , that - the axle has a locking disc at each end and each locking disc is coupled to the axle's movement, - each slide has a locking profile associated with its assigned locking disc, - the respective locking disc engages in the assigned locking profile depending on the position of the locking lever to fix the assigned position of the slide, or is out of engagement to release the assigned slide. [8] Electric motor auxiliary and retrofit drive according to claim 4, characterized by that the carrier has a detent profile, such as detent holes or detent grooves, and the stop component is a detent pin, the detent pin interacting with the detent profile to anchor the slide in an intermediate position.

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