Patent Publication Number: US-2021163051-A1

Title: Foldable golf trolley

Description:
The invention is concerned with a golf trolley for mounting a golf bag. The golf trolley is foldable between an operational mode in which the golf trolley can be used to hold a golf bag with golf clubs and a transport mode in which the golf trolley is folded-up for transportation, for example in the trunk of a vehicle or during a flight. The golf trolley comprises a main frame, a handle portion, which is pivotably attached to the main frame at a handle joint, pivotable about a handle joint axis between an extended handle position for the operational mode and a transport handle position for the transport mode. A first wheel is attached to a first wheel mount, wherein the first wheel mount is pivotably attached to the main frame, pivotable about a swivel axis between an extended angle for the operational mode and a transport angle for the transport mode. 
     Golf trolleys are widely used to transport golf bags filled with golf clubs, which can be mounted on or to the golf trolley. A golf trolley typically has two or three wheels and can be pushed in front of or pulled behind a golf player. Since golf trolleys are rather large and bulky, trolleys are known that can be folded up in order to transport the trolley. Therefore, some parts, like the handle or a main wheel mount, can be folded in order to reduce the amount of space necessary for the golf trolley. 
     This has the disadvantage, that the trolley has to be set up every time before the use of the golf trolley, which can be very time consuming. 
     US 2013/234420 A1 discloses a collapsible combination golf bag and cart system, which transitions between a compact mode and an expanded mode. This is achieved by leg assemblies, which are pivotally mounted on the back plate on the bag body. The rear wheels are mounted on a corresponding rear axle at the distal end of a leg pivot plate. The leg plate is connected at its proximal end to a pivot joint mounted on the back plate. The leg pivot plate is, thus, rotatable around the pivot joint. Further, the leg pivot plate can swing out driven by a ramp feature that acts to urge the leg member outward away from the bag body during the rotation of the leg plate. Hence, the leg plate is rotatable about two axis, first, the pivot axle and secondly to an axis perpendicular to it for folding out the leg plate together with the rear wheels in order to enlarge the distance between the two rear wheels. 
     US 2003/234501 A1 discloses a wheeled base for a golf club bag with a pair of spaced-apart transport wheels provided at opposite ends thereof and further comprising a pair of spaced-apart secondary transport wheels, with an axle that can be extended telescopically from ends of said axle supporting said pair of primary transport wheels. 
     US 2006/175782 A1 discloses a golf bag with a pair of wheels that are rotationally mounted on front and lower side corners of the main frame. A connecting structure is provided such that vertical movement of a lift pipe causes the wheels to move horizontally so that the intervals between the wheels increase. 
     It is thus an object of the present invention to provide a foldable golf trolley with an easy and fast way to set up the golf trolley. 
     This object is solved with a golf trolley according to claim  1 . The golf trolley comprises a main frame for mounting a golf bag, a handle portion, which is pivotably attached to the main frame at a handle joint, pivotable about a handle joint axis between an extended handle position and a transport handle position, a first main wheel attached to a first main wheel mount, wherein the first main wheel mount is pivotably attached to the main frame, pivotable about a swivel axis between an extended angle and a transport angle. The first main wheel mount is displaceable parallel to the swivel axis between an extended position and a transport position, wherein the handle portion is mechanically coupled to the first main wheel mount such that folding the handle portion at the handle joint into its extended handle position drives the first main wheel mount to rotate about the swivel axis into its extended angle and to move linearly along the swivel axis into its extended position. Hence, the inventive golf trolley can be set-up to its operational mode with a single and simple action, saving a lot of time compared to the many steps necessary in known foldable golf trolleys. 
     In a preferred embodiment, the inventive golf trolley comprises a second main wheel attached to a second main wheel mount, wherein the second main wheel mount is pivotable about a swivel axis between an extended angle and a transport angle. The second main wheel mount is further displaceable parallel to the swivel axis between an extended position and a transport position. Hence, the second main wheel mount is pivotably and displaceably attached to the main frame and is further mechanically coupled to the handle portion, such that folding the handle portion at the handle joint drives the second main wheel mount to rotate together with the first main wheel mount and to move linearly along the swivel axis, wherein the first main wheel mount and the second main wheel mount move in opposite directions. Thereby, both wheel mounts are easily moved and the golf trolley can be even smaller in its transport mode and at the same time have a large enough track width in its operational mode that ensures safe handling of the golf trolley on the golf course without the risk of tipping over. 
     In another preferred embodiment of the inventive golf trolley, the first main wheel mount and/or the second main wheel mount is attached to the main frame via a telescopic rod, wherein the telescopic rod can rotate about the swivel axis and axially move along the swivel axis with respect to the main frame. The telescopic rod can be aligned such that its center axis corresponds to the swivel axis. Such a telescopic rod serves as a connection between the main wheel mount and the main frame that provides the necessary degree of freedom of movement and provides a sturdy connection. So even after excessive use of the golf trolley and particularly after many transitions between the transport mode and the operational mode, the proper function of the golf trolley can be ensured. Furthermore, the mounting by the telescopic rod provides a very high torsional stiffness to the golf trolley. 
     In a more preferred embodiment of the golf trolley, the telescopic rod comprises an inner tube and an outer tube, wherein the inner tube is slidably arranged in the outer tube and wherein the inner tube is connected to a first main wheel mount and the outer tube is connected to the second main wheel mount or the other way round. The telescopic rod therefore provides a movable and rotational mounting for both main wheels. 
     In another more preferred embodiment of the golf trolley, the telescopic rod is mechanically coupled to the handle portion via a sliding block guide, wherein the telescopic rod is rotational to the sliding block guide about the swivel axis and axially constrained to the sliding block guide. The sliding block guide can comprise a groove which runs basically along a circular arc at a constant radial distance to the swivel axis. The telescopic rod can have a corresponding protrusion or bolt that engages the groove of the sliding block guide. Hence, the sliding block guide and the telescopic rod are coupled in a way that allows relative rotation between the two parts and allows transmitting a force between the two parts in a direction perpendicular to the groove of the sliding block guide. 
     In an even more preferred embodiment, the golf trolley comprises two sliding block guides. A first sliding block guide is connected to the inner tube and a second sliding block guide is connected to the outer tube and the two sliding block guides are coupled via a toothed wheel between two gear racks. The toothed wheel can be rotationally mounted to the main frame. Hence, the inner tube and outer tube move antiparallel, wherein their center does not move with respect to the main frame. Hence, the telescopic rod, the main wheel mounts and thus the main wheels move symmetrically and the golf trolley stays balanced in every position. 
     In another preferred embodiment of the golf trolley, the telescopic rod is mechanically coupled to the handle portion via a carrier element, wherein the telescopic rod is rotationally constrained to the carrier element about the swivel axis and axially movable along the swivel axis with respect to the carrier element. The carrier element can preferably be a carrier tube that can be arranged around the inner tube and the outer tube of the telescopic rod. It provides an easy way for rotationally driving the telescopic rod without axially constraining the telescopic rod to the main frame. 
     In another preferred embodiment of the golf trolley, the telescopic rod has guiding pin protruding from the shell surface of the telescopic rod, The telescopic rod is surrounded by a drive sleeve with a helical guide slot for achieving a rotational and/or axial movement of the telescopic rod. This allows a simple, reliable and space-saving drive mechanism for a combined rotational and axial movement to be realized, particularly preferred when the drive sleeve is connected to a gear wheel of a gear system for driving the movement of the main wheel mounts. 
     In another preferred embodiment of the golf trolley, the handle portion is mechanically coupled to the first main wheel mount and/or the second main wheel mount via a rotatable shaft. A rotatable shaft provides an easy and durable way to transmit the force applied from a user to the handle portion in an upper part of the golf trolley to the mechanics for the wheels in a lower part of the golf trolley. 
     In a more preferred embodiment of the golf trolley, the shaft is coupled to the sliding block guide by a linear drive lever mechanism, for transforming a rotation of the shaft to a linear movement of the sliding block guide. A lever mechanism is easy to produce, very sturdy and provides the necessary leverage to move the main wheel mounts. 
     In another more preferred embodiment of the golf trolley, the shaft is coupled to the carrier element by a rotational drive lever mechanism with a first lever and a second lever, wherein the first lever and the second lever are basically parallel, when the golf trolley is in an operational mode. Hence, when a rotational force is applied to the main wheel mounts, what is typically the case when the golf trolley is moved over the golf court, this force is not transmitted to the shaft. Therefore, the golf trolley does not accidently transform into the transport mode, when it is moved over uneven surfaces. 
     In another preferred embodiment, the golf trolley comprises a movable locking device for engaging the handle portion and/or the shaft to prevent folding of the handle portion and/or rotating of the shaft. When the golf trolley is moved on a golf court, it is handled by a user at the handle portion. The locking device can prevent the user from accidently folding the golf trolley at the handle joint and thereby transforming the golf trolley into the transport mode. Preferably, the golf trolley comprises a first locking device that engages the handle portion and a second locking device that engages the shaft, wherein the first locking device and the second locking device move together. Thus, the forces acting on the locking devices, when the golf trolley is handled, are divided on two separate elements. Since the forces acting on a single locking device are thus smaller, the stability of the device is increased. 
     In another preferred embodiment of the golf trolley, the first main wheel and/or the second main wheel is pivotably attached to the main wheel mount and comprises a first lock position on a first side of the main wheel mount and a second lock position on a second side of the main wheel mount. The main wheel can be locked in the first lock position at a first angle and in a second lock position at a second angle, wherein the first angle and the second angle differ by basically 180°. Through the different wheel positions, the track width of the golf trolley can additionally be adjusted. With a wheel position that results in a wide track width, the golf trolley can be handled off-road on extreme uneven surfaces. For the transport mode, the wheels can be rotated in a position with an even smaller track width, further reducing the space required for the golf trolley in the transport mode. 
     In another preferred embodiment, the golf trolley comprises a support wheel, releasably mounted to the main frame by a support wheel mount, wherein the support wheel mount comprises a key feature for engaging a recess of the main frame through an opening, wherein the key feature fits through the opening in a first orientation and does not fit through the opening in a second orientation. With a support wheel, the golf trolley can be handled more easily. Through the releasable engagement of the support wheel, the golf trolley can for example be modified from a two-wheeled golf trolley to a three-wheeled golf trolley and back in an easy way. The mounting with the key feature provides an easy and stable way of connecting the support wheel. 
     In another preferred embodiment, the golf trolley comprises a brake device, with a toothed wheel, rotationally coupled to the first wheel, second wheel and/or support wheel and a locking bolt, arranged to engage a recess in the toothed wheel and a spring, forcing the locking bolt in the direction of the toothed wheel. The brake device can prevent the golf trolley from rolling away unintendedly on a sloping terrain. A brake device with a locking bolt and toothed wheel is particularly reliable, since it does not rely on friction but comprises interlocking parts. 
     In a more preferred embodiment, the golf trolley further comprises a brake lever and a brake cable connecting the locking bolt with the brake lever, wherein the brake lever has a self-locked open position in which the locking bolt is prevented from engaging the toothed wheel and a self-locked closed position in which the locking bolt can engage a recess in the toothed wheel. The self-locking function can be provided by a rotatable brake lever that has its top dead-center between the open position and the closed position. Hence, a force is necessary to move the brake lever from the open position to the closed position or the other way around. 
     The inventive golf trolley can be manually driven by a user or comprise an electric motor arranged in the first wheel, the second wheel and/or the support wheel. The corresponding battery can be arranged in the respective wheel together with the motor or can be housed in the main frame. Such an electrically driven golf trolley is easier to maneuver, especially on large golf courts and for elderly people. 
     Additional advantages, features and possibilities of use of the present invention also result from the following description of exemplary embodiments and the drawing. Thereby, all described and/or figuratively shown features by themselves or in any combination make up the subject-matter of the present invention, even independent of their summary in the claims or their references. 
    
    
     
         FIG. 1 : shows the inventive golf trolley in an operational mode; 
         FIG. 2 : shows the inventive golf trolley in a transport mode, together with an attached golf bag; 
         FIG. 3 : shows a schematic view of the telescopic rod of the golf trolley mounted to the main frame; 
         FIG. 4 : shows the handle portion of the golf trolley; 
         FIG. 5 : shows the main folding mechanism of the golf trolley according to a first embodiment; 
         FIG. 6 : shows another view of the main folding mechanism of the golf trolley according to  FIG. 5 ; 
         FIG. 7  shows the support wheel mount of the golf trolley; 
         FIG. 8 : shows the support wheel mount of  FIG. 7  mounted to the main frame; 
         FIG. 9 a  to  c   : show the mounting steps of the support wheel mount; 
         FIG. 10 : shows the brake mechanism of the support wheel with the brake device; 
         FIG. 11 : shows a detailed view of the brake device of the support wheel; 
         FIG. 12 : shows the brake lever mechanism; 
         FIG. 13 : shows another view of the brake lever mechanism; 
         FIG. 14 : shows a third view of the brake lever mechanism; 
         FIG. 15 : shows the elongated part of the main frame with the locking mechanism; 
         FIG. 16 a, b   : show detailed views of the locking mechanism; 
         FIG. 17 : shows the wheel joint of the main wheel; 
         FIG. 18 a, b   : show an umbrella mount of the golf trolley. 
         FIG. 19 : shows the main folding mechanism of the golf trolley according to a second embodiment; 
         FIG. 20 : shows another view of the main folding mechanism of the golf trolley according to  FIG. 19 ; 
     
    
    
     The inventive golf trolley  1 , shown in  FIG. 1  in its operational mode, comprises a main frame  2  with an elongated part  2   a , to which a handle portion  3  is connected via a handle joint  4 . The handle portion  3  is, therefore, foldable about a handle joint axis  5  at the handle joint  4 . A golf bag mount  13  is arranged at the elongated part  2   a  of the main frame  2 , to which a golf bag can be connected releasably. 
     The golf trolley  1  further comprises a first main wheel  6  connected to a first main wheel mount  7  which is in turn connected to the main frame  2 . The golf trolley  1  further comprises a second main wheel  9  mounted to a second main wheel mount  10  which is in turn mounted to the main frame  2 . The first main wheel mount  7  and second main wheel mount  10  are attached to the main frame  2  via a telescopic rod  14 , such that the first main wheel mount  7  and the second main wheel mount  10  are rotatable about a swivel axis  8 , which forms the center axis of the telescopic rod  14 . In the operational mode shown in  FIG. 1 , the first main wheel mount  7  and the second main wheel mount  10  are in their extended angle. Additionally, the telescopic rod  14  can slide into and slide out of the main frame  2  and, therefore, the first main wheel mount  7  and second main wheel mount  10  can also move axially along the swivel axis  8 . In the operational mode shown in  FIG. 1 , the first main wheel mount  7  and the second main wheel mount  10  are in their extended position. 
     The golf trolley  1  additionally comprises a support wheel  11  which is releasably mounted via a support wheel mount  12  to the main frame  2 . 
       FIG. 2  shows a transport mode of the inventive golf trolley  1 . The first main wheel mount  7  and the second main wheel mount  10  are rotated into a transport angle, where the first main wheel mount  7  and the second main wheel mount  10  are basically parallel to the elongated part  2   a  of the main frame  2 . Furthermore, the telescopic rod  14  is retracted into the main frame  2 . Hence, the first main wheel mount  7  and the second main wheel mount  10  are close to the main frame  2 . The handle portion  3  is folded along the handle joint axis  5  in its transport handle position. The support wheel  11  with its support wheel mount  12  is removed from the golf trolley  1  for transportation. The amount of space required for the golf trolley  1  is strongly reduced in the transport mode compared to the operational mode shown in  FIG. 1 . 
       FIG. 3  shows the telescopic rod  14  mounted to the main frame  2 . The telescopic rod  14  comprises an inner tube  15  and an outer tube  16  and is mounted in a carrier tube  17 . The carrier tube  17  is mounted to the main frame via two bearings  18 ,  19  arranged at its ends, an inner tube bearing  18  at its first end and an outer tube bearing  19  at its second end. The inner tube bearing  18  and the outer tube bearing  19  provide a rotatable mounting for the carrier tube  17  to the main frame  2 . Furthermore, the inner tube  15  is slidably arranged inside of the inner tube bearing  18  such that the inner tube  15  can axially move inside the inner tube bearing  18  and relative to the carrier tube  17 . The outer tube  16  is slidably arranged inside the outer tube bearing  19  such that the outer tube  16  can axially move inside the outer tube bearing  19  and relative to the carrier tube  17 . Additionally, a support bearing  20  is arranged inside the carrier tube  17  and slidably engages an inner wall of the carrier tube  17 . The support bearing  20  is further mounted to an end of the outer tube  16  and the inner tube  15  is slidably arranged inside the support bearing  20 , such that the inner tube  15  can axially move with respect to the outer tube  16 . Inner tube  15 , outer tube  16  and carrier tube  17  are rotationally constrained to each other and can rotate together with respect to the main frame  2 . The inner tube  15  and the outer tube  16  can slide into the carrier tube  17  and slide out of the carrier tube  17 . 
       FIG. 4  shows the elongated part  2   a  of the main frame  2  of the golf trolley  1  with the handle portion  3 . The handle portion  3  is connected to the elongated part  2   a  of the main frame  2  via a handle joint  4  which comprises a bevel gear wheel  21  which is rotationally constrained to the handle portion  3 . The bevel gear wheel  21  engages a corresponding bevel gear wheel  22   a  mounted on a shaft  22  which is arranged inside of the elongated part  2   a  of the main frame  2 . When the handle portion  3  is moved at the handle joint  4 , the bevel gear wheel  21  is rotating with respect to the main frame  2  and through its engagement with the bevel gear wheel  22   a  on the shaft  22 , the shaft  22  is driven rotationally. 
       FIG. 5  shows the main mechanism for driving the movement of the main wheel mounts  7 ,  10  with the main wheels  6 ,  9  according to a first embodiment. The shaft  22 , arranged inside the elongated part  2   a  of the main frame  2 , extends from the handle portion  3  down to the main mechanism. At the end of the shaft  22 , a spur gear  23  is arranged with a first toothed wheel  23   a , connected to the shaft  22  and in engagement with a second toothed wheel  23   b  connected to a linear drive lever mechanism  24 . Hence, the linear drive lever mechanism  24  is driven by the shaft  22  and thus by the movement of the handle portion  3 . 
     The linear drive lever mechanism  24  comprises a first lever connected at one end to the second toothed wheel  23   b  and with the other end to a mid-portion of a second lever. This second lever is rotationally connected to the main frame at one end and to a third lever at the other end. The third lever of the linear drive lever mechanism  24  is connected to a first linear drive carriage  25 . The linear drive lever mechanism  24  thus transforms the rotational movement of the spur gear  23  to a linear movement. The first linear drive carriage  25  is thus moved linearly. The first linear drive carriage  25  comprises a gear rack  25   a  which is connected to a second linear drive carriage  26  with a corresponding gear rack  26   a  via a toothed wheel. Since the toothed wheel is rotationally mounted to the main frame  2 , a linear movement of the first linear drive carriage  25  results in a linear movement of the second linear drive carriage  26  in the opposite direction. 
     As can be seen in  FIG. 6 , the first linear drive carriage  25  is connected to a sliding block guide  27 . The sliding block guide  27  is in turn connected to an outer tube  16  of the telescopic rod  14 . In the same way, the second linear drive carriage  26  is connected via a corresponding sliding block guide to the inner tube  15  of the telescopic rod  14 . Through the connections via the sliding block guides  27 , the axial movement of the linear drive carriages  25 ,  26  can be transmitted to the inner tube  15  and the outer tube  16  without rotationally constraining the inner tube  15  and the outer tube  16  to the sliding block guide  27 . The sliding block guides  27  comprise grooves in which a protrusion or bolt connected to the inner tube  15  and/or the outer tube  16  can glide, when the telescopic rod  14  is rotated with respect to the main frame  2 . The carrier tube  17  can have slots that act as a feed through for a protrusion or bolt connecting the inner tube and outer tube with the corresponding sliding block guides  27 . 
     Additionally, the second toothed wheel  23   b  is further connected to a first bevel gear wheel  30  of the rotational drive which engages a second bevel gear wheel  31 . The second bevel gear wheel  31  drives a rotational drive lever mechanism comprising a first rotational drive lever  32  and a second rotational drive lever  33 . The first rotational drive lever  32  is connected and rotationally constrained to the second bevel gear wheel  31  at its first end and rotationally connected to the second rotational drive lever  33  at its second end. The second rotational drive lever  33  is in turn connected to the carrier tube  17  and thus to the telescopic rod  14 . Therefore, the telescopic rod  14  is rotationally driven by the second toothed wheel  23   b . When the telescopic rod  14  is rotated such that the main wheel mounts  7 ,  10  are in their extended angle, the first rotational drive lever  32  and the second rotational drive lever  33  are basically parallel to each other. Thus, no rotational force is transmitted from the telescopic rod  14  to the first rotational drive lever  32 . 
     With regard to  FIGS. 19 and 20 , a second embodiment of the main mechanism for driving the movement of the main wheel mounts  7 ,  10  is described. The shaft  22 , arranged inside the elongated part  2   a  of the main frame  2 , extends from the handle portion  3  down to the main mechanism identically to the first embodiment described before. The rotary motion of the shaft  22  is transmitted to a gear system  60 , e.g. via two bevel gear wheels  61   a ,  61   b.    
     The main mechanism for driving comprises besides the gear system  60  a telescopic drive  70 , which simultaneously causes a rotation and an axial movement of the main wheel mounts  7 ,  10  in the manner already described with respect to the swivel axis  8 . The telescopic drive  70  has on each side of the gear system  60  a telescopic rod  71  with a flange  72  for fixing the wheel mounts  7 ,  10  and one or two guiding pins  73  protruding radially from the shell surface of the telescopic rod  71 . The telescopic rod  71  is surrounded by a drive sleeve  74  with a helical guide slot  75  in which the guiding pin(s)  73  are guided. Thus, upon rotation of the drive sleeve  74  relative to the telescopic rod  71 , i.e. when guide pin  73  is guided within the guide slot  75 , the telescopic rod  71  is moving axially with respect to the swivel axis  8 . When the guide pin  73  is approaching the end of the guide slot  75 , the telescopic rod  71  is swilling around the swivel axis  8 . In order to achieve the opposed positioning movements of the telescopic rods  71  on the opposed sides of the gear system, the helical guide slots  75  in the drive sleeves  74  are arranged in mirror image form. 
     The drive sleeves  74  are fixed to a gear wheel  62  of the gear system  60  for movement of the telescopic drive. As shown in  FIG. 20 , the telescopic rod  71  is supported by a control sleeve  76 . Further, the drive sleeve  74  may be protected by a protection sleeve (not shown in the drawings) surrounding the drive sleeve  74  and/or the control sleeve  76 . Both, the control sleeve  76  and, optionally, the protection sleeve are rigidly fixed to the main frame  2 . The rotation of the drive sleeve  74  drives the telescopic rods  71  in and out, whereby the rigid control sleeve  76  controls the axial and radial movement. 
     For showing the structure of the driving sleeve  74  and the engagement with the guide pin  73  of the telescopic rod  71 , the control sleeve  76  and the protection sleeve are omitted on the left-hand side of the telescopic drive shown in  FIG. 19 . 
       FIG. 7  shows the support wheel  11  with the support wheel mount  12 . The support wheel mount  12  comprises a key feature  34  for mounting the support wheel  11  to the main frame  2 . The key feature  34  has a mainly cylindrical form with two flattened parts on opposite sides. The support wheel mount  12  further comprises a brake cable  28  for actuating a brake device  39 . The brake cable  28  is mounted to a rotatable cable mount  29 . Rotating the rotatable cable mount  29  applies a force to the brake cable  28 . 
       FIG. 8  shows the support wheel mount  12  mounted to the main frame  2 . The key feature  34  is arranged inside a recess  35  of the main frame  2 . The recess  35  comprises an opening  36  which is smaller than the recess  35 . The main frame comprises a lock mechanism  37  that prevents the support wheel mount  12  from rotating about the key feature  34  axis. Pushing the lock mechanism  37  unlocks the support wheel mount  12  and allows rotating of the support wheel mount  12  about der key feature  34 . A protective lid  38  covers the opening  36  and the recess  35 . 
     The mechanism for mounting the support wheel mount  12  to the main frame  2  is described in  FIGS. 9 a  to 9 c    by the several mounting steps. In  FIG. 9 a    the support wheel mount  12  is separate from the main frame  2 . It is arranged in an angle that aligns the key feature  34  of the support wheel mount  12  to the opening  36  of the recess  35  of the main frame  2 . 
     As shown in  FIG. 9 b   , the two flattened parts of the key feature  34  have a distance that corresponds to the size of the opening  36 . Hence, with the angle of the key feature  34  aligned to the opening  36 , the key feature  34  fits through the opening  36  and can, thus, be inserted into the recess  35 . 
     After inserting the key feature  34  into the recess  35  through opening  36 , the support wheel mount  12  is rotated about a key feature axis as shown in  FIG. 9 c   . Therefore, the key feature turns inside the recess  31  and is no more aligned to the opening  36 . Hence, the support wheel mount  12  with the key feature  34  cannot move out of the recess  35  but is held tight in the recess  35 . Further, the support wheel mount  12  is prevented from rotating back, by the lock mechanism  37 , which automatically engages the support wheel mount  12 , when it is rotated in the locked position of the key feature  34 . 
       FIG. 10  shows the support wheel mount  12  mounted to the main frame  2 . The support wheel  11  is not shown. The support wheel mount  12  comprises a brake device  39  with a toothed wheel  40  and a locking bolt  41 . The support wheel mount  12  is mounted inside the main frame  2  in the recess  35  with its key feature  34 . The main frame  2  comprises a connection lever  42  for connecting a part of a brake cable  28  inside the main frame  2  with the rotatable cable mount  29  of the support wheel mount  12  and thus a part of the brake cable  28  of the support wheel mount  12 . The connection lever  42  is rotatable about a connection lever axis and is spring loaded, as can be seen in  FIG. 8 . It comprises a first arm  43  which is connected to the brake cable  28  and a second arm  44  that interacts with the rotatable cable mount  29  of the support wheel mount  12 . The second arm  44  abuts a protrusion of the rotatable cable mount  29 . Applying a force to the brake cable  28  inside the main frame  2  rotates the connection lever  42 . Thereby, the second arm  44  is moved with respect to the rotatable cable mount  29 , which can thus rotate about its axis. 
       FIG. 11  shows the brake device  39  in more detail with the toothed wheel  40  which is rotationally constrained to the support wheel  11 . A locking bolt  41  is pushed towards the toothed wheel  40  with a locking bolt spring  41 . Furthermore, the brake cable  28  is connected to the locking bolt  41  and pulling the locking bolt  41  against the tension of the locking bolt spring  45  out of engagement of the toothed wheel  36 . When no force is applied to the brake cable  28 , the locking bolt spring  45  pushes the locking bolt  41  into a recess of the toothed wheel  36  and pulls the brake cable  28  thus rotating the rotatable cable mount  29 . This prevents the toothed wheel and, thus, the support wheel  11  from turning. When the second arm  44  pushes against the rotatable cable mount  29 , the rotatable cable mount  29  is rotating and thus applying a force to the brake cable  28 . The brake cable thus pulls the locking bolt  37  out of its engagement with the toothed wheel  40 . The support wheel  11  can thus rotate freely. 
       FIG. 12  shows the brake lever  46  with an outer part  46   a  for interacting with the user and an inner part  46   b  that forms the connection to the brake cable  28 . The brake cable  28  is connected to the connection lever  42  at its other end. The brake lever  46  can be rotated from a first position where a first abutting surface  48  contacts a stop feature  47  and a second position in which a second abutting surface  49  contacts the stop feature  47 . The brake cable is guided inside a cable guide  28   a.    
       FIG. 13  shows the brake lever in the first position. The first abutting feature  48  contacts the stop feature  47  and the distance between a mounting point of the brake cable  28  on the brake lever  46   b  to and opening or end of the cable guide  28   a  is shorter than in a second position. The brake cable  28  is, thus, loose and no force is applied to the brake cable  28  by the brake lever  46 . The spring loaded connection lever  42  can thus pull the brake cable  28  to rotate and apply a force to the rotatable cable mount  29 . 
       FIG. 14  shows a second position of the brake lever  46 . The second abutting surface  49  of the brake lever  46  is in contact with the stop feature  47 . The mounting point of the brake cable  28  is at a larger distance from the end of the cable guide  28   a  and, thus, moving the brake lever  46  from the first position to the second position applies a force to the brake cable  28 . This force rotates the connection lever  42  and moves the second arm away from the rotatable cable mount  29 . 
     At an intermediate position between the first position and the second position of the brake lever  46 , the distance between the mounting point of the brake cable  28  and an opening or end of the cable guide  28   a  is even larger than in the second position. Hence, since a force is applied to the brake cable  28  by the spring loaded connection lever  42 , the brake lever  46  is self-retaining in the first position and in the second position. 
       FIG. 15  shows the elongated part  2   a  of the main frame  2  with the golf bag mount  13  and the shaft  22  turning in the interior of the main frame  2 . Arranged inside the main frame  2  is a locking mechanism which is shown in more detail in  FIGS. 16 a    and  16   b.    
     The locking mechanism comprises a first locking device  51  and a second locking device  53  which can be moved together axially between a locking-position and an open-position. The open-position is shown in  FIG. 16 a    in which the first locking device  51  is arranged below a first locking feature  50  rotationally constrained to the bevel gear wheel  21 . Thus, the bevel gear wheel  21  can rotate freely. The second locking device  53  is arranged below a second locking feature  52  which is mounted to and rotationally constrained to the shaft  22 . Hence, the second locking feature  52  and the shaft  22  can rotate freely. 
       FIG. 16 b    shows the locking mechanism of  FIG. 16 a    in its locking-position. The first locking feature  50  is engaged with the first locking device  51  and the second locking feature  52  is engaged with the second locking device  53 . Hence, neither the bevel gear wheel  21  nor the shaft  22  can rotate freely. A lock spring  54  forces the first locking device  51  and the second locking device  53  in its locking-position. 
       FIG. 17  shows the mounting of the main wheels  6  to the main wheel mount  7 . The main wheel  6  is mounted via a wheel joint  55  to the main wheel mount  7  and can thus be pivoted about an axis perpendicular to the wheels rotating axis. The main wheel  6  can be locked in a first position on a first side of the main wheel mount  7  and on a second side of the main wheel mount  7  in a second position. The wheel joint  55  comprises a wheel joint button  56  to release the locking mechanism of the wheel joint  55  and, thus, allows rotating the wheel  6  about the wheel joint  55 . 
       FIGS. 18 a , 18 b    show an umbrella mount which can be moved in a first position shown in  FIG. 18 a    in which the umbrella mount is mainly parallel to the main frame  2 , when it is not in use. In  FIG. 18 b    the umbrella mount  57  is erected to an upright position, in which an umbrella can be fixed to the umbrella mount  57  for holding the umbrella. 
     REFERENCE NUMERALS 
     
         
         
           
               1  golf trolley 
               2  main frame 
               2   a  elongated part 
               3  handle portion 
               4  handle joint 
               5  handle joint axis 
               6  first main wheel 
               7  first main wheel mount 
               8  swivel axis 
               9  second main wheel 
               10  second main wheel mount 
               11  support wheel 
               12  support wheel mount 
               13  golf bag mount 
               14  telescopic rod 
               15  inner tube 
               16  outer tube 
               17  carrier tube 
               18  bearing inner tube 
               19  bearing outer tube 
               20  support bearing 
               21  bevel gear wheel 
               22  shaft 
               22   a  bevel gear wheel 
               23  spur gear 
               23   a  first toothed wheel 
               23   b  second toothed wheel 
               24  linear drive lever mechanism 
               25  first linear drive carriage 
               25   a  gear rack 
               26  second linear drive carriage 
               26   a  gear rack 
               27  sliding block guide 
               28  brake cable 
               28   a  brake cable guide 
               29  rotatable cable mount 
               30  first bevel gear wheel 
               31  second bevel gear wheel 
               32  first rotational drive lever 
               33  second rotational drive lever 
               34  key feature 
               35  recess 
               36  opening 
               37  lock mechanism 
               38  protective lid 
               39  brake device 
               40  toothed wheel 
               41  locking bolt 
               42  connection lever 
               43  first arm 
               44  second arm 
               45  locking bolt spring 
               46  brake lever 
               46   a  brake lever outer part 
               46   b  brake lever inner part 
               47  stop feature 
               48  first abutting surface 
               49  second abutting surface 
               50  first locking feature 
               51  first locking device 
               52  second locking feature 
               53  second locking device 
               54  lock spring 
               55  wheel joint 
               56  wheel joint button 
               57  umbrella mount 
               60  gear system 
               61   a,b  bevel gear wheel 
               62  gear wheel 
               70  telescopic drive 
               71  telescopic rod 
               72  flange for fixing the wheel mounts 
               73  guiding pin 
               74  drive sleeve 
               75  helical guide slot 
               76  control sleeve