A cargo bike and a frame for a cargo bike

Abstract

The invention is a cargo bike (100) comprising a frame (103), a rear wheel (109), a first front wheel (110a), a second front wheel, a pedal arrangement (112), a cargo platform (104) and an electric motor (111). The frame has a first end of the frame (101) and a second end of the frame (102). The frame comprises a seat tube (105), a head tube (107), a first cargo support tube (116a), a second cargo support tube and a front wheel tube at the first end of the frame. The front wheels are attached to the ends of the front wheel tube. The first ends of the front wheel tube are positioned higher than the horizontal plane of the cargo support tubes. The cargo platform is fixed above the cargo support tubes.

Description

[0001] A cargo bike and a frame for a cargo bike

[0002] The invention relates to a cargo bike comprising three wheels: a rear wheel, a first front wheel and a second front wheel, a frame having a first end of the frame and a second end of the frame, an electric motor configured to rotate the rear wheel, a pedal arrangement, a steering arrangement for turning the front wheels, and a cargo platform, and the frame comprises a seat tube, a head tube, a first rear wheel support tube, a second rear wheel support tube, a lower frame structure, an upper frame structure, a first cargo support tube and a second cargo support tube, and the lower frame structure and the upper frame structure are connected between the seat tube and the head tube and said frame structures are on the same vertical plane, and the first cargo support tube and the second cargo support tube are on the same horizontal plane, and the rear wheel is between the first rear wheel support tube and the second rear wheel support tube. The invention also relates to a frame for a three wheeled cargo bike.

[0003] BACKGROUND

[0004] Cargo bikes are increasingly used to transport goods without relying on motor vehicles. Especially in the urban area, where comparatively short distances have to be overcome and flexibility and agility are required, cargo bikes are frequently used. They represent an environmentally conscious and cost-effective alternative to motor vehicles. They allow for transport baskets, shells or the like so that heavy and / or bulky items can be transported. Also, the transport of children with appropriately equipped cargo bikes with, for example, a transport basket with integrated child seats, is possible.

[0005] A common design is a three-wheeled cargo bike with a transport basket in front. Compared to two-wheelers with a large transport volume, this construction allows for a relatively short overall length. In this case, the basket can either be rigidly connected to the frame or pivot with steering movements. The volume and shape of the transport container depend heavily on the design of the steering arrangement and the transport basket. This in turn has a significant impact on the riding characteristics of the bike.

[0006] Some cargo bikes have a long wheelbase with a cargo area in between the rider and the front wheels. This location of the cargo area improves weight distribution. The major disadvantage of a long wheelbase is that the maneuverability is greatly reduced. The long wheelbase is slow to react to steering inputs and requires exaggerated turning of the handle bar. The minimum turning radius is also increased and makes it difficult to maneuver in tight quarters. Also, because the centre of gravity is high when the cargo bike is loaded, the bike may be unstable.

[0007] Patent publication DE102016110346 discloses a three-wheeled cargo bike where a cargo container is placed between two front wheels. The publication mentions that an electric motor may be used to assist in riding the bike when transporting heavy loads However, the structure of the frame of the bike is complex and many of the problems described earlier are quite evident in the design. Additionally, it is practically impossible to attach to that kind of a frame a cargo container larger than 100 litre.

[0008] BRIEF DESCRIPTION

[0009] The object of the invention is a solution that can significantly reduce the disadvantages and drawbacks of the prior art. In particular, the object of the invention is a cargo bike that improves safety and increases cargo capacity.

[0010] The objects of the invention are attained with a method that is characterised by what is stated in the independent patent claims. Some advantageous embodiments of the invention are disclosed in the dependent claims.

[0011] The invention is a cargo bike comprising a frame, a rear wheel, a first front wheel, a second front wheel, a pedal arrangement and an electric motor. The frame has a first end of the frame and a second end of the frame. The frame comprises a seat tube, a head tube, a first cargo support tube, a second cargo support tube and a front wheel tube at the first end of the frame. The front wheels are attached to the ends of the front wheel tube. The first ends of the front wheel tube are higher than the horizontal plane of the cargo support tubes. The cargo platform is fixed above the cargo support tubes.

[0012] When reference is made in the text to the upper or the lower parts or respective directions such as down or up or bottom, a situation is described in which the cargo bike according to the invention is in use and on the ground (i.e. wheels are on the ground). Also, when reference is made to the vertical or horizontal directions or surfaces, the cargo bike is placed similarly. These are also applicable to the frame of the cargo bike. In one embodiment of the invention is a cargo bike comprising three wheels: a rear wheel, a first front wheel and a second front wheel, a frame having a first end of the frame and a second end of the frame, an electric motor configured to rotate the rear wheel, a pedal arrangement, a steering arrangement for turning the front wheels, and a cargo platform. The frame comprises a seat tube, a head tube, a first rear wheel support tube, a second rear wheel support tube, a first cargo support tube and a second cargo support tube, and a front wheel tube. The first cargo support tube and the second cargo support tube are at least partly on the same horizontal plane. The rear wheel is between the first rear wheel support tube and the second rear wheel support tube. The steering arrangement comprises a steering shaft, a first turning shaft, a second turning shaft and a joint arrangement. The steering shaft is connected to the joint arrangement, and the first turning shaft is connected to the first front wheel and the joint arrangement, and the second turning shaft is connected to the second first front wheel and the joint arrangement. The cargo platform is fixed on the first cargo support tube and the second cargo support tube, i.e. said cargo support tubes are at least partly below the cargo platform. In one advantageous embodiment of the invention the front wheel tube is at the first end of the frame, and the front wheel tube has a first end of the front wheel tube and a second end of the front wheel tube, and the first front wheel is attached to the first end of the front wheel tube and the second front wheel is attached to the second end of the front wheel tube. The first end of the front wheel tube and the second end of the front wheel tube are higher than the horizontal plane of the first cargo support tube and the second cargo support tube. The first turning shaft and the second turning shaft are configured in such a way that the first turning shaft passes over the first cargo support tube and the second turning shaft passes over the second cargo support tube.

[0013] In one embodiment of the cargo bike, the first rear wheel support tube and the second rear wheel support tube are connected to the seat tube in such a way that height of the connection points of the rear wheel supporting tubes is the same as the height of the rotating axis of the pedal arrangement or they differ 20% of said height at maximum. This feature improves balance and reduces stress forces in the frame.

[0014] In a second embodiment of the cargo bike, the electric motor and the pedal arrangement are between the lower frame structure and the upper frame structure and on the lower frame structure. Positioning the motor below the rider of the bike makes it easier to manage the total weight distribution of the bike. In a third embodiment of the cargo bike, the connection between the pedal arrangement and the rear wheel is a belt, and the belt forms a loop, and one way or another, the first rear wheel support tube or the second rear wheel support tube is configured to go through the loop. This feature allows the belt to be changed without detaching the rear wheel. If the fastening of the rear wheel is loosened, the wheel can be moved towards the pedal arrangement and the belt can be lifted from the gearwheels of the rear wheel and the pedal arrangement. This makes servicing easier.

[0015] In one embodiment oft the cargo bike, the first cargo support tube (and the second cargo support tube are connected to the front wheel tube. In a fourth embodiment of the cargo bike, the middle part of the front wheel tube is on the level of the horizontal plane of the first cargo support tube and the second cargo support tube, and the first cargo support tube and the second cargo support tube are connected to the middle part of the front wheel tube. This feature allows straight cargo support tubes, which reduces stress forces and makes it easier to implement the cargo platform. In a fifth embodiments of the cargo bike, the middle part of the front wheel tube is at the level of the horizontal plane of the first cargo support tube and the second cargo support tube, and the first cargo support tube and the second cargo support tube are connected to the middle part of the front wheel tube. In one embodiment of the cargo bike, the joint arrangement is on the plane formed by the middle part of the front wheel tube, the first cargo support tube and the second cargo support tube.

[0016] In a sixth embodiment of the cargo bike, the joint arrangement is configured to push and pull on the first turning shaft and the second turning shaft in such a way that the front wheel on the inner curve turns more than the front wheel on the outer curve. This improves turning efficiency.

[0017] In a seventh embodiment of the cargo bike, the frame further comprises a front protection plate, and the front protection plate is connected to the front wheel tube and the joint arrangement is fixed to the upper side of the front protection plate. This feature further protects the turning shafts and the joint arrangement.

[0018] In an eighth embodiment of the cargo bike, the cargo bike further comprises at least one battery holding arrangement to accept a battery for the electric motor, and the battery holding arrangement is positioned on the head tube in such a way that the battery in the battery holding arrangement is on the left side or on the right side of the head tube. This feature leaves more room for the rider, but still provides easy access to the battery. In a ninth embodiment of the cargo bike, the first front wheel and the second front wheel are tilted inwards, i.e. the distance between the upper edges of the front wheels is shorter than the distance between the lower edges of the front wheels. This improves the steering characteristics of the bike.

[0019] In a tenth embodiment of the cargo bike, the diameters of the wheels are between 30 cm and 55 cm. Using such wheels can lower the centre of gravity. In an eleventh embodiment of the cargo bike, the diameter of the rear wheel is greater than the diameters of the front wheels. This does not significally raise the centre of gravity and allows for better power efficiency.

[0020] In a twelfth embodiment of the cargo bike, the distance between the head tube and the front wheel tube is greater than 100 cm. This feature improves the stability of the bike when making turns.

[0021] In a thirteenth embodiment of the cargo bike, the connection point of the upper frame structure and the seat tube is higher than the connection point of the upper frame structure and the head tube. This feature both leaves more room for the rider and directs stress forces to the lower parts of frame where the frame parts can be strengthened and thus the centre of gravity is kept low.

[0022] In one embodiment of the cargo bike, the distance between the head tube and the front wheel tube is greater than 60 cm.

[0023] In one embodiment of the cargo bike, the steering shaft is between the first cargo support tube and the second cargo support tube.

[0024] In one embodiment of the cargo bike, the joint arrangement is between the first cargo support tube and the second cargo support tube.

[0025] In one embodiment of the cargo bike, the frame further comprise a lower frame structure and an upper frame structure, and the lower frame structure and the upper frame structure are connected between the seat tube and the head tube and said frame structures are on the same vertical plane. In one embodiment of the cargo bike, the electric motor and the pedal arrangement are located between the lower frame structure and the upper frame structure and positioned on the lower frame structure.

[0026] In one embodiment of the invention is a frame for a three-wheeled cargo bike, which cargo bike has one rear wheel and two front wheels. The frame has a first end of the frame and a second end of the frame. The frame comprises a seat tube, a head tube, a first rear wheel support tube, a second rear wheel support tube, a lower frame structure, an upper frame structure, a first cargo support tube and a second cargo support tube. The lower frame structure and the upper frame structure are connected between the seat tube and the head tube and said frame structures are on the same vertical plane. The first cargo support tube and the second cargo support tube are at least partly on the same horizontal plane. The first rear wheel support tube and the second rear wheel support tube are configured to receive the rear wheel between the two. In one advantageous embodiment of the invention, the frame further comprise a front wheel tube at the first end of the frame, and the front axle has a first end of the front wheel tube and a second end of the front wheel tube, and the front wheel tube is configured in such a way that one front wheel is attached to the first end of the front wheel tube and another front wheel is attached to the second end of the front wheel tube. The first end of the front wheel tube and the second end of the front wheel are higher than the horizontal plane of the first cargo support tube and the second cargo support tube. The cargo support tubes are configured to receive a cargo container of the cargo bike over them, i.e. said cargo support tubes are at least partly below the cargo container, and the frame is configured to protect at least some parts of the steering arrangement.

[0027] In one embodiment of the frame, the first cargo support tube (and the second cargo support tube are connected to the front wheel tube, and the first cargo support tube, the second cargo support tube and the front wheel tube form a protective structure for at least some parts of the steering arrangement.

[0028] It is an advantage of the invention that it provides a cargo bike that is safe to drive and still has a substantial transport capacity. Also, the frame of the cargo bike protects the steering arrangement and other vulnerable parts of the bike.

[0029] One advantage of the invention is that differently sized riders can easily make use of it.

[0030] It is a further advantage of the invention that it can be easily optimized for many user segments by using different kind of cargo platforms.

[0031] The invention also implements a cargo bike that has a low centre of gravity. Also, the structure is such that no suspension is needed.

[0032] The frame of the cargo bike is lighter than frames of the corresponding prior art cargo bikes. DESCRIPTIONS OF THE FIGURES

[0033] In the following, the invention is described in detail. The description refers to the accompanying drawings, in which

[0034] Figure 1 shows an example of a cargo bike according to an embodiment,

[0035] Figure 2 shows the cargo bike of Figure 1 as seen from below,

[0036] Figure 3 shows the rear end of the cargo bike of Figure 1 ,

[0037] Figure 4 shows the front end of the cargo bike of Figure 1 ,

[0038] Figure 5 shows a second example of a cargo bike according to an embodiment as seen from the front of the bike,

[0039] Figure 6 shows the cargo bike of Figure 5 as seen from above,

[0040] Figure 7a shows an example of a cargo bike frame according to an embodiment,

[0041] Figure 7b shows the cargo bike frame of Figure 7a as seen from the side,

[0042] Figure 8a shows a second example of a cargo bike frame according to an embodiment, and

[0043] Figure 8b shows the cargo bike frame of Figure 8a as seen from above.

[0044] DETAILED DESCRIPTIONS OF THE FIGURES

[0045] The embodiments in the following description are given as examples only and someone skilled in the art can carry out the basic idea of the invention also in some other way than what is described in the description. Though the description may refer to a certain embodiment or embodiments in several places, this does not mean that the reference would be directed towards only one described embodiment or that the described characteristic would be usable only in one described embodiment. The individual characteristics of two or more embodiments may be combined and new embodiments of the invention may thus be provided. Figure 1 shows an embodiment of a cargo bike 100. The cargo bike is a tricycle, i.e. it has three wheels: a rear wheel 109, a first front wheel 110a and a second front wheel (not visible in Figure 1). The cargo bike comprises a frame 103, an electric motor 111 , a pedal arrangement 112, a steering arrangement and a cargo platform 104. The frame has a first end of the frame 101 and a second end of the frame 102. The front end of the cargo bike is at or near the first end of the frame, and the rear end of the cargo bike is at or near the second end of the frame. The frame comprises a seat tube 105, a head tube 107, a first rear wheel support tube 117a and a second rear wheel support tube (not visible), a lower frame structure, an upper frame structure, a first cargo support tube 116a and a second cargo support tube (not visible).

[0046] The seat tube 105 is a tube having an upper end and a lower end. A seat 106 is placed on the upper end. The rider of the cargo bike 100 sits on the seat facing towards the first end of the frame 101. The head tube 107 is a tube having an upper end and a lower end. At the upper end of the head tube are bike handles that are used for steering the cargo bike. In some embodiments, when the rider turns the bike handles a shaft inside the head tube turns and moves at least some part of the steering arrangement, which causes the front wheels to turn in the corresponding direction. The turning radius depends on how far the bike handles are turned. The steering arrangement is positioned in such a way that the frame 103 protects at least some parts of the steering arrangement. In some embodiments, some parts of the steering arrangement are between the first cargo support tube 116a and the second cargo support tube. In some embodiments, a taillight is attached to the seat tube.

[0047] The electric motor 111 is configured to rotate the rear wheel 109. The pedal arrangement 112 is used to control the motor and the power the motor produces is conveyed to the rear wheel by a belt 113. The inventors have found that using a belt in the transmission is in many cases more beneficial than using a chain. The pedal arrangement comprises two pedals the rider treads when driving the bike. The pedals have a rotating axis. In this embodiment, the electric motor is a central motor, i.e. it is placed on the middle of the frame 103. In some embodiments, a hub motor on the rear wheel 109 is used.

[0048] The lower frame structure and the upper frame structure are connected between the seat tube 105 and the head tube 107. Said frame structures are on the same vertical plane, i.e. they are on top of each other. In the embodiment shown on Figure 1 the lower frame structure is a plate-like structure and the electric motor 111 is fixed to it. The upper frame structure is a tube. The connection point of the upper frame structure and the seat tube is higher than the connection point of the upper frame structure and the head tube. This means that the upper frame structure slopes downwards towards the first end of the frame 101 . This provides more room for the rider. Also, this kind of structure directs stress forces on the lower parts of the frame, which can be reinforced. This keeps the centre of gravity down, which in turn increases stability of the cargo bike 100. The lower frame structure and the upper frame structure interconnects the rear part of the cargo bike and the front part of the cargo bike. The rear part includes at least the rear wheel 109, the first rear wheel support tube 117a, the second rear wheel support tube and the seat tube. The front part includes at least the head tube, the first cargo support tube, the second cargo support tube, the steering arrangement, the first front wheel 110a and the second front wheel. The rear part and the front part are connected below the head tube 107 by frame support parts. These frame support parts serve to connect the frame parts and to strengthen the frame. The cargo support tubes are connected to the frame support parts. In this embodiment, the lower frame structure 118 is connected both the head tube and the frame support parts.

[0049] The first rear wheel support tube 117a and the second rear wheel support tube are placed in parallel and form a fork-like structure and the rear wheel 109 is between the wheel support tubes. The rear wheel is connected to the wheel support tubes. The wheel support tubes are connected to the seat tube 105. The height of the connection points of the rear wheel supporting tubes is the same as the height of the rotating axis of the pedal arrangement 112 or differs 20% of that height at maximum. In some embodiments, the diameter of the rear wheel 109 is greater than the diameters of the front wheels. In that case, the height of the connection points of the rear wheel supporting tubes at the seat tube may be such that the rear wheel does not tilt the first end of the frame 101 downwards, i.e. the longitudinal axis of the frame 103 is substantially horizontal. In some embodiments, the diameters of the wheels are between 30 cm and 55 cm.

[0050] The wheel support tubes are positioned in such a way that the first rear wheel support tube 117a or the second rear wheel support tube is configured to go through the loop formed by the belt. When the connection point of the wheel support tube goes through the loop of the belt, it is at the same level as the inside area of the belt, so that the belt can be easily detached by loosening the rear wheel connection from the wheel support tubes and moving the rear wheel towards the first end of the frame 101. When this is done, the belt can be lifted from the gearwheels at the rear wheel and the pedal arrangement. This makes servicing of the power transmission arrangement easier. This method is applicable even if a chain is used. In some embodiments, the cargo bike comprises a rear rack 114 that is fixed to the wheel support tubes and the seat tube 105. If there is a taillight on the seat tube and the rear rack covers it, the taillight can be detached and moved to the rear part of the rear rack.

[0051] Different embodiments of the cargo bike 100 use different cargo platforms 104. The cargo platforms are, for example, box-like vessels, containers with lids, platforms without rims, seats for persons, cages, and some such.

[0052] The first cargo support tube 116a and the second cargo support tube form a support area where the cargo support tubes are on the same horizontal plane, and this support area is used as a base for the cargo platform 104. The cargo support tubes extend from the frame support parts below the head tube 107 to the first end of cargo bike frame 101. In this embodiment, the support area is lower than the level of the lower frame structure 118, i.e. the distance from the ground is less in the support area than the distance from the ground in the lower frame structure. The cargo support tubes curve outwards from the middle line of the frame in the horizontal plane. This means that the distance between the cargo support tubes is greater in the middle of the support area than at the first end of cargo bike frame 101 and where the cargo support tubes are connected to the frame support parts. In this embodiment, the maximum distance between the cargo support tubes is less than the distance between the first front wheel 110a and the second front wheel.

[0053] For receiving the batteries of the electric motor 111 the cargo bike 100 comprises at least one battery holding arrangement 108. The battery holding arrangement is positioned against the head tube 107 in such a way that the battery in the battery holding arrangement is positioned on the left side or on the right side of the head tube. In that case, the battery is easy to reach and still does not encroach on the rider. The shape of the battery holding arrangement corresponds to the shape and size of the battery.

[0054] Figure 2 shows the cargo bike 100 of Figure 1 as seen from below. The cargo bike comprises the rear wheel 109, the first front wheel 110a, the second front wheel 110b, the frame 103, the electric motor 111 , the belt 113, the rear rack 114, the pedal arrangement 112, the steering arrangement 115 and the cargo platform 104. The frame has a first end of the frame 101 and a second end of the frame 102. The frame comprises the seat tube 105, the head tube 107, the first rear wheel support tube 117a and the second rear wheel support tube 117b, the lower frame structure 118, the upper frame structure 119, the first cargo support tube 116a and the second cargo support tube 116b.

[0055] When the belt 113 is removed for servicing, the rear rack 114 is detached and the rear wheel is moved towards the pedal arrangement 112 as was described before. The first rear wheel support tube 117a and the second rear wheel support tube 117b comprise attaching slots, which are approximately parallel to the longitudinal axis of the wheel support tubes or at least partly so. The axle of the rear wheel is attached in to these slots. Both the pedal arrangement and the rear wheel have gearwheels that the belt circles around for conveying energy from the electric motor to the rear wheel. The rear wheel is moved as much as is needed to lift the belt from the gearwheel of the rear wheel and then the belt is lifted from the gearwheel of the pedal arrangement. For reattaching the belt, the procedure is performed in reverse order.

[0056] The steering arrangement 115 comprises shafts and arms and joints between them. The steering arrangement is for relaying movements of the handles to corresponding movements of the front wheels. The steering arrangements comprise parts that are parallel to the cargo support tubes and, in particular, parallel to the cargo support tubes in the support area. At least some of these parts are between said cargo support tubes in the support area. The cargo support tubes protect said parts. In some embodiment there are additional protection plates for protecting at least some of the joints of the steering arrangement. In the embodiment of Figure 2 there are protection plates below the head tube 107 and near the first end of cargo bike frame 101.

[0057] The cargo platform 104 is fixed to the cargo support tubes below the cargo platform. In this example, the cargo platform extends over the first end of cargo bike frame 101. Of course, the cargo platforms can be implemented in a multitude of different ways.

[0058] Figure 3 shows the rear end of the cargo bike 100 of Figure 1. For the sake of clarity, the rear rack and the cargo platform are removed from Figure 3. The cargo bike comprises the rear wheel 109, frame 103, the electric motor 111 , the belt 113, the battery holding arrangement 108 and the pedal arrangement 112. The frame has a second end of the frame 102. The frame comprises the seat tube 105, the head tube 107, the first rear wheel support tube 117a and the second rear wheel support tube 117b, the lower frame structure 118, the upper frame structure 119, the first cargo support tube 116a and the second cargo support tube 116b. The belt 113 connects the pedal arrangement 112 and the electric motor 111 to the rear wheel 109 in order to transfer power from the motor in order to rotate the rear wheel. The belt is on one side of the cargo bike 100, on the side of the first rear wheel support tube or on the side of the second rear wheel support tube. The first rear wheel support tube 117a and the second rear wheel support tube 117b are connected to the seat tube 105 and the connection point of the rear wheel support tubes is such that one of the rear wheel support tubes goes through the loop of the belt.

[0059] The connection point of the upper frame structure 119 and the seat tube 105 is higher than the connection point of the upper frame structure and the head tube 107. The seat tube is curved towards the head tube. There is a curvature point where the seat tube is closest to the head tube, and in this embodiment, the connection point of the upper frame structure and the seat tube is above this curvature point. In this embodiment, the upper frame structure slopes downwards until it turns parallel to the lower frame structure 118. The turning point is positioned in such a way that the electric motor 111 and the pedal arrangement 112 are at least mostly below the sloping part of upper frame structure. There are frame support parts below the head tube 107 for strengthening the frame and for providing a platform for connecting the frame parts together.

[0060] Figure 4 shows the front end of the cargo bike 100 of Figure 1. For the sake of clarity, the cargo platform is removed from Figure 4. The cargo bike comprises the frame 103, the first front wheel 110a, the second front wheel 110b and the steering arrangement 115. The frame has the first end of the frame 101. The frame comprises the head tube 107, the first cargo support tube 116a and the second cargo support tube 116b. The frame further comprises a front wheel tube 120. At the top of the head tube are handles for turning the cargo bike.

[0061] The first cargo support tube 116a and the second cargo support tube 116b form the support area for the cargo platform. The cargo support tubes extend from the frame support parts below the head tube 107 to the first end of the frame 101 where they are connected to the front wheel tube 120. The frame 103 has a longitudinal symmetry axis (a middle line). The cargo support tubes are bent so as to extend outwards from the symmetry axis at the middle part of the cargo support tubes (i.e. the support area). When defining the support area, the cargo support tubes are parallel to each other and the symmetry axis. The maximum distance between the cargo support tubes is less that the length of the front wheel tube. Close to the front wheel tube the cargo support tubes bend towards each other, i.e. the distance between the cargo support tubes diminishes. This makes room for the front wheels to turn and prevents unwanted material from getting stuck between the frame and the front wheels. In some embodiments, the distance between the head tube and the front wheel tube is greater than 60 cm. In some cases, shorter distances than that may cause unbalance when making sharp turns with the cargo bike. In some embodiments, to fix the cargo platform onto the cargo support tubes, the frame includes additional attachment arrangements. These may comprise some holes for bolts or similar arrangements.

[0062] The front wheel tube 120 is at the first end of the frame 101. The first front wheel 110a and the second front wheel 110b are connected to the ends of the front wheel tube. The ends of the front wheels curve upwards in such a way that they are above the level of the support area.

[0063] In this embodiment, the steering arrangement 115 comprises a steering shaft 121 , a first turning shaft 122a, a second turning shaft 122b and a joint arrangement 125. The steering shaft is essentially parallel to the symmetry axis of the frame and the steering shaft extends from below the head tube 107 to near the first end of the frame 101 where the steering shaft is connected to the joint arrangement. The first turning shaft is connected to the first front wheel 110a and the joint arrangement, and the second turning shaft is connected to the second first front wheel 110b and the joint arrangement. The first turning shaft passes over the first cargo support tube 116a and the second turning shaft passes over the second cargo support tube 116b. Advantageously, this is done in such a way that the turning shafts and the cargo support tubes do not touch each other. The steering shaft is connected to a system that transforms the movements of the handles to movements of the steering shaft. In some embodiments, these movements are such that the end of the steering shaft near the first end of the frame moves horizontally, and in some embodiments, these movements are longitudinal, and in other embodiments, these movements are rotational, i.e. the steering shaft rotates around its longitudinal axis. These movements move the joint arrangement and the turning shafts. The joint arrangement is configured simultaneously to push and pull on the first turning shaft and the second turning shaft according to the movements of the steering shaft and at the same time the movements of the handles. In some embodiments, the joint arrangement is configured to move the turning shafts in such a way that the front wheel on the inner curve turns more than the front wheel on the outer curve. For protecting the joint arrangement and the connections between the shafts and, in some embodiments, the joint arrangement, there is a front protection plate fixed to the front wheel tube 120. The front protection plate is at least partly horizontal. The joint arrangement is fixed to the upper side of the front protection plate.

[0064] The first cargo support tube 116a and the second cargo support tube 116b are connected to the front wheel tube 120. The first cargo support tube, the second cargo support tube and the front wheel tube form a protective structure for at least some parts of the steering arrangement. The steering shaft 121 , the first turning shaft 122a, the second turning shaft 122b and the joint arrangement 125 are above the level formed by bottom parts of the cargo support tubes and the front wheel tube when the bike 100 is in use. This means that the steering arrangement do not extend below said protective structure (i.e. the steering arrangement do not extend closer to the ground than parts of said protective structure when the bike is in use). The steering shaft is between the first cargo support tube and the second cargo support tube. The joint arrangement is between the first cargo support tube and the second cargo support tube. Because the front wheel tube is at the first end of the frame 101 , it forms a bumper at the first end of frame for protecting the steering arrangement. Possible obstacles hit first to the front wheel tube, and the steering arrangement behind (or parts of the steering arrangement behind the front wheel tube) are protected from the direct hits. The turning shafts are also protected by the protective structure. Otherwise, the connection points of the turning shafts and wheels can be quite prone for damages and faults.

[0065] Figure 5 shows a second example of a cargo bike 500 as seen from front of the bike. For the sake of clarity, a cargo platform is removed from Figure 5. The cargo bike comprises a frame 503, a first front wheel 510a, a second front wheel 510b and a steering arrangement 515. The frame comprises a head tube 507, a battery holding arrangement 508, a first cargo support tube 516a, a second cargo support tube 516b and a front wheel tube 520.

[0066] The front wheel tube 520 has a first end of the front wheel tube 523 and a second end of the front wheel tube 524. The first front wheel is attached to the first end of the front wheel tube and the second front wheel is attached to the second end of the front wheel tube. The end of the front wheel tube are bent upwards in such a way that the first end of the front wheel tube and the second end of the front wheel tube are higher than the horizontal plane of the first cargo support tube 516a and the second cargo support tube 516b. The middle part of the front wheel tube is horizontal and is at the level of the cargo support tubes. The attachment of the front wheels is such that the front wheels are inclined slightly inward. This means that the upper parts of the front wheels are closer to each other than the lower parts of the front wheels.

[0067] The steering arrangement 515 comprises a steering shaft 521 , a first turning shaft 522a, a second turning shaft 522b and a joint arrangement 525. The arrangement of these parts is practically similar as was described with the previous example. Below the head tube 507 are frame support parts. There is a slot in the frame support parts and the steering shaft is inside this slot. There is an arrangement below the head tube for moving the steering shaft when handles on the head tube are turned. When the steering shaft is moved, the joint arrangement moves simultaneously with both turning shafts in such a way that the front wheels turn in the same direction. In some embodiments, the front wheel on the inner curve, i.e. in the turning direction, turns more than the other front wheel on the outer curve.

[0068] In this embodiment, the joint arrangement 525 is fixed to the frame 503 in such a way that the joint arrangement is at least partly above the cargo support tubes. The first turning shaft 522a and the second turning shaft 522b are above the cargo support tubes and substantially horizontal, i.e. the cargo support tubes are parallel to the horizontal middle part of the front wheel tube 520.

[0069] Figure 6 shows the front end of the cargo bike 500 of Figure 5 as seen from above. The cargo bike comprises the frame 503, the first front wheel 510a, the second front wheel 510b, the steering arrangement 515. The frame has the front end of the frame 501. The frame comprises the head tube 507, the first cargo support tube 516a, the second cargo support tube 516b, the front wheel tube 520, an upper frame structure 519, a front protection plate 526 and several attachment arrangements 527. The cargo platform is attached to the attachment arrangements. The attachment arrangements comprise parts that keep the bottom of the cargo platform above the steering arrangement. In some embodiments, the bottom of the cargo platform is shaped to provide room for the steering arrangement and other equipment of the cargo bike, such as wiring.

[0070] The steering arrangement 515 comprises the steering shaft 521 , the first turning shaft 522a, the second turning shaft 522b and the joint arrangement 525. In this embodiment, the steering shaft is configured to move longitudinally towards and away from the front end of the frame 501 according to the movements of the handles of the cargo bike 500. In this embodiment, when the handles are turned left (as seen from the rider’s point of view), the steering shaft is moved away from the front end of the frame and the steering shaft pulls a part of the joint arrangement 525 and turns it. The turning part of the joint arrangement the pulls the second turning shaft and pushes the first turning shaft. The second turning shaft pulls the second front wheel in such a way that it turns left and the first turning shaft pushes the first front wheel in such a way that it turns left. When the handles are turned right, the directions are reversed.

[0071] Figures 7a and 7b show a frame 703 of a cargo bike. Figure 7a shows the frame slightly from above and Figure 7b shows the frame from the side. Both Figures 7a and 7b are explained here in unison.

[0072] The frame 703 has a first end of the frame 701 and a second end of the frame 702. The frame comprises a seat tube 705, a head tube 707, a battery holding arrangement 708, a first rear wheel support tube 717a, a second rear wheel support tube 717b, a lower frame structure 718, an upper frame structure 719, a first cargo support tube 716a, a second cargo support tube 716b, a front wheel tube 720 and a front protection plate 726. Below the head tube are frame support parts. The frame support parts connect the head tube, the frame structures, and the cargo support tubes.

[0073] The front wheel tube 720 has a first end of the front wheel tube 723 and a second end of the front wheel tube 724. The first cargo support tube 716a and the second cargo support tube 716b are in the same horizontal level. This level extends from the frame support parts to the front wheel tube. The front wheel tube is shaped in such a way that the ends of the front wheel tube are above the level that the cargo support tubes define. This means that when the front wheels are connected to the ends of the front wheel tube, the centre of gravity is lower than on the conventional cargo bike frames. This effect is even clearer when the cargo platform is in place and loaded. The low centre of gravity makes the cargo bike more stable and thus safer.

[0074] The lower frame structure 718, the upper frame structure 719, the seat tube 705, and the head tube 707 form an area where a pedal arrangement and an electric motor of the cargo bike can be installed. In this embodiment, there are additional mooring plates on the walls of said area, and these mooring plates are used for attaching the pedal arrangement and the electric motor to the frame 703.

[0075] In this embodiment, the frame 703 further comprises fixing plates 728 and cargo support arrangements 729. The fixing plates are for fixing a cargo platform to the frame. The fixing plates are on the inner sides of the cargo support tubes. The support arrangements are for supporting the cargo platform. The support arrangements are on the first end of the frame 701 fixed to the front wheel tube 720 and they extend outwards, i.e. away from the cargo bike. There are means for attaching the cargo platform to the support arrangements. In this embodiment, the support arrangements support the bottom of the front part of the cargo platform. In some embodiments, the support arrangements are configured to support also other parts of the cargo platform. For example, they can extend to the sides of the cargo platform. In some embodiments, there are support arrangements on the cargo support tubes.

[0076] Figures 8a and 8b show a frame 803 of a cargo bike. The cargo bike is a threewheeled bike having one rear wheel and two front wheels and comprises a cargo platform. Figure 8a shows the frame from slightly above and Figure 8b shows the frame from above. Both Figures 8a and 8b are explained here together. To make the functioning of the frame clearer, some parts of the cargo bike are added to Figures 8a and 8b.

[0077] The frame 803 has a first end of the frame 801 and a second end of the frame 802. The frame comprises a seat tube 805, a head tube 807, a first rear wheel support tube 817a, a second rear wheel support tube 817b, a lower frame structure 818, an upper frame structure 819, a first cargo support tube 816a, a second cargo support tube 816b, a front wheel tube 820 and a front protection plate 826. The front wheel tube 820 has a first end of the front wheel tube 823 and a second end of the front wheel tube 824.

[0078] A steering arrangement 815 and rims of the wheels have been attached to the frame 803. The rims have hubs of the rims and include brakes and other parts. The steering arrangement comprises a steering shaft 821 , a first turning shaft 822a, a second turning shaft 822b and a joint arrangement 825. The implementation of the steering arrangement is practically similar to that of Figure 6. The steering shaft is between the first cargo support tube 816a and the second cargo support tube 816b and the steering shaft is essentially parallel to the cargo support tubes. The steering shaft and the turning shafts are connected to the joint arrangement. The ends of the turning shafts that are connected to the joint arrangement are above the steering shaft, i.e. the connection points between the turning shafts and the joint arrangement are higher than the connection point between the steering shaft and the joint arrangement. The steering shafts are above the horizontal level formed by the cargo support tubes. The connection points of the ends of the turning shafts to the rims of the front wheels are below the hubs, i.e. the connection points of the ends of the turning shafts are below the rotational centres of the front wheels. In some embodiments, the turning shafts are horizontal or near horizontal. The cargo platform is shaped in such a way that the cargo platform does not press against the turning shafts. In some embodiments, the cargo platform is lifted by some fixing arrangements to make room for the turning shafts between the cargo platform and the frame.

[0079] Some advantageous embodiments of the device according to the invention have been described above. The invention is however not limited to the embodiments described above, but the inventive idea can be applied in numerous ways within the scope of the claims.

Claims

Patent claims1. A cargo bike (100; 500) comprising three wheels: a rear wheel (109), a first front wheel (110a; 510a) and a second front wheel (110b; 510a), a frame (103; 503; 703; 803) having a first end of the frame (101 ; 501 ; 701 ; 801) and a second end of the frame (102; 502; 702; 802), an electric motor (111) configured to rotate the rear wheel, a pedal arrangement (112), a steering arrangement (115; 515; 815) for turning the front wheels, and a cargo platform (104), and the frame comprises a seat tube (105; 705; 805), a head tube (107; 507; 707; 807), a first rear wheel support tube (117a, 717a; 817a), a second rear wheel support tube (117b; 717b; 817b), a first cargo support tube (116a; 516a; 716a; 816a) and a second cargo support tube (116b; 516b; 716b; 816b), and a front wheel tube (120; 520; 720; 820), and the first cargo support tube and the second cargo support tube are at least partly on the same horizontal plane, and the rear wheel is between the first rear wheel support tube and the second rear wheel support tube, and the steering arrangement (115; 515; 815) comprises a steering shaft (121 ; 521 ; 821), a first turning shaft (122a; 522a; 822a), a second turning shaft (122b; 522b; 822b) and a joint arrangement (525; 825), and the steering shaft is connected to the joint arrangement, and the first turning shaft is connected to the first front wheel (110a; 510a) and the joint arrangement, and the second turning shaft is connected to the second first front wheel (110b; 510b) and the joint arrangement, and the cargo platform is fixed on the first cargo support tube and the second cargo support tube, i.e. said cargo support tubes are at least partly below the cargo platform, characterised in that the front wheel tube is at the first end of the frame, and the front wheel tube has a first end of the front wheel tube (523; 723; 823) and a second end of the front wheel tube (524; 724; 824), and the first front wheel is attached to the first end of the front wheel tube and the second front wheel is attached to the second end of the front wheel tube, and the first end of the front wheel tube and the second end of the front wheel tube are higher than the horizontal plane of the first cargo support tube and the second cargo support tube, and the first turning shaft passes over the first cargo support tube (116a; 516a; 716a; 816a) and the second turning shaft passes over the second cargo support tube (116b; 516b; 716b; 816b).

2. A cargo bike (100; 500) according to claim 1 , characterised in that the first rear wheel support tube (117a, 717a; 817a) and the second rear wheel support tube (117b, 717b; 817b) are connected to the seat tube (105; 705; 805) in such a waythat the height of the connection points of the rear wheel supporting tubes is the same as the height of the rotating axis of the pedal arrangement (112) or it differs 20% of that height at maximum.

3. A cargo bike (100; 500) according to claim 1 or 2, characterised in that the steering shaft (121 ; 521 ; 821) is between the first cargo support tube (116a; 516a; 716a; 816a) and the second cargo support tube (116b; 516b; 716b; 816b).

4. A cargo bike (100; 500) according to any of claims 1 to 3, characterised in that the joint arrangement (525; 825) is between the first cargo support tube (116a; 516a; 716a; 816a) and the second cargo support tube (116b; 516b; 716b; 816b).

5. A cargo bike (100; 500) according to any of claims 1 to 4, characterised in that the connection between the pedal arrangement (112) and the rear wheel (109) is a belt (113), and the belt forms a loop, and the first rear wheel support tube (117a, 717a; 817a) or the second rear wheel support tube (117b; 717b; 817b) is configured to go through the loop.

6. A cargo bike (100; 500) according to any of claims 1 to 5, characterised in that the first cargo support tube (116a; 516a; 716a; 816a) and the second cargo support tube (116b; 516b; 716b; 816b) are connected to the front wheel tube (120; 520; 720; 820).

7. A cargo bike (100; 500) according to any of claims 1 to 6, characterised in that the middle part of the front wheel tube (120; 520; 720; 820) is at the level of the horizontal plane of the first cargo support tube (116a; 516a; 716a; 816a) and the second cargo support tube (116b; 516b; 716b; 816b), and the first cargo support tube and the second cargo support tube are connected to the middle part of the front wheel tube.

8. A cargo bike (100; 500) according to claim 7, characterised in that the joint arrangement (525; 825) is on the plane formed by the middle part of the front wheel tube (120; 520; 720; 820), the first cargo support tube (116a; 516a; 716a; 816a) and the second cargo support tube (116b; 516b; 716b; 816b).

9. A cargo bike (100; 500) according to any of claims 1 to 8, characterised in that the joint arrangement (525; 825) is configured to push and pull on the first turning shaft (122a; 522a; 822a) and the second turning shaft (122b; 522b; 822b) in such a way that the front wheel on the inner curve turns more than the front wheel on the outer curve.

10. A cargo bike (100; 500) according to any of claims 1 to 9, characterised in that the frame (103; 503; 703; 803) further comprises a front protection plate (526; 826), and the front protection plate is connected to the front wheel tube (120; 520; 720; 820) and the joint arrangement (525; 825) is fixed to the upper side of the front protection plate.

11. A cargo bike (100; 500) according to any of claims 1 to 10, characterised in that the cargo bike further comprises at least one battery holding arrangement (108; 508) for receiving a battery for the electric motor (111), and the battery holding arrangement is positioned on the head tube (107; 507; 707; 807) in such a way that the battery in the battery holding arrangement is on the left side or on the right side of the head tube.

12. A cargo bike (100; 500) according to any of claims 1 to 11 , characterised in that the first front wheel (110a; 510a) and the second front wheel (110b; 510a) are tilted inwards, i.e. the distance between upper edges of the front wheels is shorter than the distance between lower edges of the front wheels.

13. A cargo bike (100; 500) according to any of claims 1 to 12, characterised in that the diameters of the wheels are between 30 cm to 55 cm.

14. A cargo bike (100; 500) according to any of claims 1 to 13, characterised in that the diameter of the rear wheel (109) is greater than the diameters of the front wheels.

15. A cargo bike (100; 500) according to any of claims 1 to 14, characterised in that the distance between the head tube (107; 507; 707; 807) and the front wheel tube (120; 520; 720; 820) is greater than 60 cm.

16. A cargo bike (100; 500) according to any of claims 1 to 15, characterised in that the frame further com prise a lower frame structure (118; 718; 818) and an upper frame structure (119; 519; 719; 819), and the lower frame structure and the upper frame structure are connected between the seat tube and the head tube and said frame structures are on the same vertical plane.

17. A cargo bike (100; 500) according to any of claims 1 to 16, characterised in that the electric motor (111) and the pedal arrangement (112) are located between the lower frame structure (118; 718; 818) and the upper frame structure (119; 519; 719; 819) and positioned on the lower frame structure.

18. A cargo bike (100; 500) according to any of claims 1 to 17, characterised in that the interconnecting point of the upper frame structure (119; 519; 719; 819) and the seat tube (105; 705; 805) is higher than the connection point of the upper frame structure and the head tube (107; 507; 707; 807).

19. A frame (103; 503; 703; 803) for a three wheeled cargo bike, which cargo bike comprises one rear wheel, two front wheels, and a steering arrangement, and the frame has a first end of the frame (101 ; 501 ; 701 ; 801) and a second end of the frame (102; 502; 702; 802), and the frame comprises a seat tube (105; 705; 805), a head tube (107; 507; 707; 807), a first rear wheel support tube (117a, 717a; 817a), a second rear wheel support tube (117b; 717b; 817b), a first cargo support tube (116a; 516a; 716a; 816a), a second cargo support tube (116b; 516b; 716b; 816b), and a front wheel tube (120; 520; 720; 820), and the first cargo support tube and the second cargo support tube are at least partly on the same horizontal plane, and the first rear wheel support tube and the second rear wheel support tube are configured to receive the rear wheel between them, and the cargo support tubes are configured to receive a cargo container of the cargo bike over them, i.e. said cargo support tubes are at least partly below the cargo container, characterised in that the frame further comprises a lower frame structure (118; 718; 818) and an upper frame structure (119; 519; 719; 819), and the lower frame structure and the upper framestructure are connected between the seat tube and the head tube and said frame structures are on the same vertical plane, and the front wheel tube is at the first end of the frame, and the front wheel tube has a first end of the front wheel tube (523; 723; 823) and a second end of the front wheel tube (524; 724; 824), and the front wheel tube is configured in such a way that one front wheel is attached to the first end of the front wheel tube and another front wheel is attached to the second end of the front wheel tube, and the first end of the front wheel tube and the second end of the front wheel tube are higher than the horizontal plane of the first cargo support tube and the second cargo support tube, and the frame is configured to protect at least some parts of the steering arrangement.

20. A frame (103; 503; 703; 803) according to claim 19, characterised in that the first cargo support tube (116a; 516a; 716a; 816a) and the second cargo support tube (116b; 516b; 716b; 816b) are connected to the front wheel tube (120; 520; 720; 820), and the first cargo support tube, the second cargo support tube and the front wheel tube form a protective structure for at least some parts of the steering arrangement.

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