GRIP ROD OF BABY CARRIAGE

Abstract: To reliability accomplish a lock state of a grip rod in a linear state and a bent state in a grip rod of a foldable baby carriage, first and second portions (4, 5) of the grip rod (3), which are interconnected by a joint (6), are interconnected by a rigid link member (28) so that the first and second portions operate symmetrically with each other with respect to the joint (6). Because the angles formed by these first and second portions (4, 5) to the joint (6) can be kept at the same angle in this way, lock members (23, 24) can be reliably engaged with lock recesses (19, 20) for the open state or with lock recesses (21, 22) for the closed state.

Description: The present invention relates to a foldable grip bar for coupling a pair of push rods of a collapsible baby carriage and being adapted to enter a linear state in an open state of the baby carriage and to enter a folded state in a closed state of the baby carriage. As a typical example of a collapsible baby carriage, there is an article of a form comprising a pair of push rods so that the space between these push rods is kept relatively wide in an open state of the baby carriage while these push rods are approached to each other in a closed state of the baby carriage. Between such a pair of push rods, a grip bar is generally coupled. In the collapsible baby carriage of the aforementioned form, a central portion of this grip bar must be rendered foldable, for example, in order to allow operations of the pair of push rods. The grip bar enters a linear state in an open state of the baby carriage, while the same enters a folded state in a closed state of the baby carriage. In the collapsible baby carriage of the aforementioned form, an operation of locking both of the linear state and the folded state of the grip bar is performed to make it possible to more strongly maintain the open state and the closed state. Such a locking mechanism is described in Japanese Utility Model Laying-Open No. 1-171772, for example. This prior art application discloses a foldable grip bar for coupling a pair of push rods of a collapsible baby carriage and being adapted to enter a linear state in an open state of the baby carriage and to enter a folded state in a closed state of the baby carriage, said foldable grip bar comprising: a first portion having an outer end rotatably supported by one of said pair of push rods; a second portion having an outer end rotatably supported by another of said pair of push rods; a joint member having one end rotatably connected to an inner end of said first portion by means of a first rotary shaft and having another end rotatably connected to an inner end of said second portion by means of a second rotary shaft; a first open state locking concave portion formed on said inner end of the first portion; a second open state locking concave portion formed on said inner end of the second portion; a first closed state locking concave portion formed on said inner end of the first portion; a second closed state locking concave portion formed on said inner end of the second portion; a first locking member movable in an axial direction of said first rotary shaft to be engaged in said first open state locking concave portion in the open state of the baby carriage and to be engaged in said first closed state locking concave portion in the closed state of the baby carriage; a second locking member movable in an axial direction of said second rotary shaft to be engaged in said second open state locking concave portion in the open state of the baby carriage and to be engaged in said first closed state locking concave portion in the closed state of the baby carriage; springs for urging said first and second locking members into engagement with said concave portions; and an unlocking member for disengaging said locking members from said concave portions against the biasing of said springs. According to such prior art, it is possible to fix the linear state and the folded state of the grip bar by engaging the locking members in the open state locking concave portions in the open state and in the closed state locking concave portions in the closed state, whereby the respective ones of the open state and the closed state of the baby carriage can be more strongly maintained. While the unlocking member must be operated when the locking is to be released, the locking members can be automatically engaged in either of the open state locking concave portions and the open state locking concave portions by actions of the springs at the time of making a locked state. In the aforementioned conventional grip bar, however, the locking members may be first engaged in the open state locking concave portion which is in the first portion and not engaged in the open state locking concave portion which is in the second portion when the same are to be engaged in the open state locking concave portions, for example, although the same are urged by the springs in the directions to be engaged in the open state locking concave portions and the closed state locking concave portions by the springs, for example. In this case, an angle at which the locking members can be engaged in the open state locking concave portion which is in the second portion must be searched for while varying the angle which is formed by the second portion with respect to the joint. To the contrary, the locking members may be first engaged only in the open state locking concave portion which is in a second concave portion. Similar matters can also be said as to such case that the locking members are to be engaged in the closed state locking concave portions. When the locking members are engaged in the open state locking concave portion or the closed state locking concave portion only in either one of the aforementioned first and second portions, an operation for attaining engagement in both portions is troublesome while the baby carriage may be carelessly used in an incomplete locking state, and this is not only unpreferable in the point of safety but may cause breakage of the baby carriage. An object of the present invention is to prevent or at least alleviate the disadvantages of the prior mechanism highlighted above. Accordingly, an object of the present invention is to try to avoid an incomplete locking state in a grip bar for a baby carriage. The present invention provides a foldable grip bar for coupling a pair of push rods of a collapsible baby carriage and being adapted to enter a linear state in an open state of the baby carriage and to enter a folded state in a closed state of the baby carriage, said foldable grip bar comprising: a first portion having an outer end rotatably supported by one of said pair of push rods; a second portion having an outer end rotatably supported by another of said pair of push rods; a joint member having one end rotatably connected to an inner end of said first portion by means of a first rotary shaft and having another end rotatably connected to an inner end of said second portion by means of a second rotary shaft; a first open state locking concave portion formed on said inner end of the first portion; a second open state locking concave portion formed on said inner end of the second portion; a first closed state locking concave portion formed on said inner end of the first portion; a second closed state locking concave portion formed on said inner end of the second portion; a first locking member movable in an axial direction of said first rotary shaft to be engaged in said first open state locking concave portion in the open state of the baby carriage and to be engaged in said first closed state locking concave portion in the closed state of the baby carriage; a second locking member movable in an axial direction of said second rotary shaft to be engaged in said second open state locking concave portion in the open state of the baby carriage and to be engaged in said second closed state locking concave portion in the closed state of the baby carriage; springs for urging said first and second locking members into engagement with said concave portions; and an unlocking member for disengaging said locking members from said concave portions against the biasing of said springs; characterised by a rigid link member having one end portion rotatably mounted at a first position on said inner end of the first portion and having an opposing end portion rotatably mounted at a second position on said inner end of the second portion, wherein an angle of a first straight line through said second position and the axis of said second rotary shaft with respect to a transversal straight line through the axis of said first rotary shaft and the axis of said second rotary shaft is  1 , and an angle of a second straight line through said first position and the axis of said first rotary shaft with respect to said transversal straight line is  2 , wherein angles  1 and  2 are on the same side of the transversal straight line and are exterior to the first straight line and the second straight line and wherein  1 is equal to  2 throughout folding and unfolding of the grip bar. Preferably, said open state locking concave portions and said closed state locking concave portions are formed from a common concave polygonally shaped portion. In order that the invention may be well understood, an embodiment thereof, which is given by may of example only, will now be described with reference to the accompanying drawings, in which : Fig. 1 illustrates a central portion of a grip bar 3 in an open state of a baby carriage 1 shown in Fig. 3, and (a) is a plan view omitting a part, (b) is a sectional/front elevational view, and (c) is a bottom plan view omitting a part; Fig. 2 illustrates the central portion of the grip bar 3 in a closed state of the baby carriage 1 shown in Fig. 4, and (a) is a plan view omitting a part, and (b) is a bottom plan view omitting a part; Fig. 3 is a perspective view showing the open state of the baby carriage 1 comprising the grip bar 3 shown in Fig. 1 and Fig. 2; and Fig. 4 is a perspective view showing the closed state of the baby carriage 1 shown in Fig. 3. Fig. 3 is a perspective view showing a collapsible baby carriage 1 to which an embodiment of the present invention is applied, and shows an open state. Fig. 4 is a perspective view showing a closed state of the baby carriage shown in Fig. 3. In Fig. 3 and Fig. 4, illustration of a seat which is mounted on the baby carriage 1 is omitted. The baby carriage 1 comprises a pair of push rods 2, and a grip bar 3 is coupled between these push rods 2. In the open state of the baby carriage 1, the pair of push rods 2 are kept at a relatively wide space as shown in Fig. 3, while the space between the pair of push rods 2 is narrowed in the closed state of the baby carriage, as shown in Fig. 4. In order to allow such operations, a central portion of the grip bar 3 is rendered foldable. The grip bar 3 has portions extending on the same axial lines with the respective push rods 2 on its both end portions, and these portions are held rotatable with respect to the respective push rods 2, as understood when Fig. 3 is compared with Fig. 4. The grip bar 3 comprises a first portion 4 forming one end portion, a second portion 5 forming another end portion, and a joint 6 coupling the first and second portions 4 and 5 respectively. Fig. 1 and Fig. 2 show the central portion of the grip bar 3. The state shown in Fig. 1 corresponds to the open state of the baby carriage 1 shown in Fig. 3, and the grip bar 3 is in a linear state in this state. On the other hand, the state shown in Fig. 2 corresponds to the closed state of the baby carriage 1 shown in Fig. 4, and the grip bar 3 is in a folded state in this state. Referring to Fig. 1, (a) is a plan view, (b) is a sectional/front elevational view, and (c) is a bottom plan view. Referring to Fig. 2, (a) is a plan view, and (b) is a bottom plan view. In Fig. 1(a) and (c) and Fig. 2(a) and (b), illustration of some elements included in the grip bar 3 is omitted. In Fig. 1 and Fig. 2, further, only inner end portions positioned on end portions on the side of the joint 6 are illustrated as the first and second portions 4 and 5. Mainly with reference to Fig. 1(b), the joint 6 comprises two housing half portions 7 and 8, and these housing half portions 7 and 8 are combined with each other thereby forming a space storing various elements in its interior. First and second bosses 9 and 10 are formed on the housing half portion 7, while first and second bosses 11 and 12 are formed on the housing half portion 8. The first bosses 9 and 11 and the second bosses 10 and 12 are aligned with each other respectively, a first rivet 13 is arranged to pass through the first bosses 9 and 11, and a second rivet 14 is arranged to pass through the second bosses 10 and 12. These rivets 13 and 14 serve functions of fixing the two housing half portions 7 and 8 to each other. Thus, a first rotary shaft 15 is provided by the first bosses 9 and 11 and the first rivet 13, while a second rotary shaft 16 is provided by the second bosses 10 and 12 and the second rivet 14. The first and second rotary shafts 15 and 16 are parallel to each other, whereby the first and second portions 4 and 5 are rotatably supported respectively. Open state locking concave portions 19 and 20 and closed state locking concave portions 21 and 22 (see Fig. 1(a) and Fig. 2(a)) are formed on respective single side surfaces 17 and 18 of the inner end portions of the first and second portions 4 and 5 extending in directions intersecting with the axial directions of the first and second rotary shafts 15 and 16 respectively. In this embodiment, the open state locking concave portion 19 and the closed state locking concave portion 21 are formed from a common polygonally shaped portion. Similarly, the open state locking concave portion 20 and the closed state locking concave portion 22 are also formed from a common concave polygonally shaped portion. Locking members 23 and 24 are arranged around the respective ones of the first and second rotary shafts 15 and 16. These locking members 23 and 24 are movable in the axial directions of the first and second rotary shafts 15 and 16, and engaged in the open state locking concave portions 19 and 20 respectively by movements thereof when the grip bar 3 is in the linear state as shown in Fig. 1, while the same are engaged in the closed state locking concave portions 21 and 22 respectively by movements thereof when the grip bar 3 is in the folded state as shown in Fig. 2. In order to engage the locking members 23 and 24 in the open state locking concave portions 19 and 20 and the closed state locking concave portions 21 and 22 as hereinabove described, springs 25 and 26 for urging the locking members 23 and 24 in directions of this engagement are arranged between the respective ones of the locking members 23 and 24 and the housing half portion 7. While the springs 25 and 26 have been provided by compression springs in this embodiment, the same may alternatively be formed by extension springs, by changing the arrangement states of the springs. In order to supply operating force for disengaging the locking members 23 and 24 from the open state locking concave portions 19 and 20 and the closed state locking concave portions 21 and 22 against the elasticity of the aforementioned springs 25 and 26, an unlocking member 27 is provided to project from the housing half portion 8. While the aforementioned locking members 23 and 24 and the unlocking member 27 have been formed by an integral part in this embodiment, these may be formed by separate parts, to integrally operate in an assembled state. Mainly with reference to Fig. 1(c) and Fig. 2(b), the first portion 4 and the second portion 5 are coupled with each other by a rigid link member 28. In more detail, an end of the rigid link member 28 is rotatably mounted on the first portion 4 on a first position of the first portion 4 around the first rotary shaft 15 through a pin 29. On the other hand, the other end of the rigid link member 28 is rotatably mounted on the second portion 5 on a second position of the second portion 5 around the second rotary shaft 16 through a pin 30. The position of the pin 29 with respect to the first rotary shaft 15 and the position of the pin 30 with respect to the second rotary shaft 16 are selected to be in an opposite relation to each other. The mutual positional relation is selected to be the following: an angle of a first straight line through the center of the pin 30, or second position, and the axis of the second rotary shaft 16 with respect to the transversal straight line through the axis of the first rotary shaft 15 and the axis of the second rotary shaft 16 is  1 , and an angle of a second straight line through the center of the pin, or first position, 29 and the axis of the first rotary shaft 15 with respect to the transversal straight line is  2 , and  1 and  2 are on the same side of the transversal straight line and are exterior to the first straight line and the second straight line, then  1 is equal to  2 throughout folding and unfolding of the grip bar. As hereinabove described, the rigid link member 26 can transmit bidirectional operations of the pushing direction and the pulling direction between the first and second portions 4 and 5 by coupling the first and second portions 4 and 5 with each other by the rigid link member 28, whereby the angles formed by the respective ones of the first and second portions 4 and 5 with respect to the joint 6 can be kept identical to each other. Namely, the first and second portions 4 and 5 are forced by the rigid link member 28 to symmetrically operate with respect to the joint 6. An operation method related to the grip bar 3 in the illustrated baby carriage 1 and an operation following the same are described. As hereinabove described, the grip bar 3 is in the state shown in Fig. 1 in the open state of the baby carriage 1 shown in Fig. 3. Namely, the locking members 23 and 24 are engaged in the open state locking concave portions 19 and 20 respectively, whereby both of the first and second portions 4 and 5 are in states unrotatable with respect to the locking members 23 and 24 as well as the joint 6 about the first and second rotary shafts 15 and 16. Therefore, the grip bar 3 is maintained in its linear state. In order to release the locking in the aforementioned open state of the baby carriage 1, the unlocking member 27 is upwardly pressed. This state is shown by broken lines in Fig. 1(b). Due to such pressing, the locking members 23 and 24 are upwardly displaced against the elasticity of the springs 25 and 26. Thus, the locking members 23 and 24 enter states disengaged from the open state locking concave portions 19 and 20. Therefore, both of the first and second portions 4 and 5 enter states rotatable about the first and second rotary shafts 15 and 16. While maintaining this state, the baby carriage 1 is converted from the open state shown in Fig. 3 to the closed state shown in Fig. 4. The aforementioned pressing operation on the unlocking member 27 may not be maintained while the baby carriage 1 is brought into the closed state from the open state. Once the baby carriage 1 starts conversion from the open state to the closed state, the locking members 23 and 24 are maintained in states placed on the side surfaces 17 and 18 of the first and second portions 4 and 5, even if the pressing operation on the unlocking member 27 is canceled. At the termination of the conversion to the closed state, the locking members 23 and 24 are automatically engaged in the closed state locking concave portions 19 and 20 by actions of the springs 25 and 26. Thus, the first and second portions 4 and 5 become unrotatable with respect to the locking members 23 and 24 as well as the joint 6, whereby the folded state of the grip bar 3 is locked. Also in case of bringing this baby carriage 1 from the closed state into the open state again, a substantially similar operation is executed, so that the locking members 23 and 24 are finally engaged in the open state locking concave portions 19 and 20, and the linear state of the grip bar 3 is locked. In each of the aforementioned conversion from the open state to the closed state and the conversion from the closed state to the open state, the operations of the first and second portions 4 and 5 are interlocked by the rigid link member 28, so that the angles formed by the respective ones of the first and second portions 4 and 5 with respect to the joint 6 are kept identical to each other. When one locking member 23 is engaged with one open state locking concave portion 19 or one closed state locking concave portion 21, therefore, the other locking member 24 is necessarily engaged with the other open state locking concave portion 20 or the other closed state locking concave portion 22, whereby a complete locking state can be reliably attained with no requirement for a troublesome operation. While the present invention has been described in relation to the illustrated embodiment, some additional modifications are possible within the range of the present invention. For example, respective shapes of the locking members, and the open state locking concave portions and the closed state locking concave portions can be modified in various ways. Further, the baby carriage to which the present invention is applied is not restricted to that shown in Fig. 3 and Fig. 4, but may be any one so far as the same is a baby carriage having a grip bar coupling a pair of push rods with each other and having a central portion which is rendered foldable. It will be appreciated from the described embodiment that the rigid link member transmits both operations in a pushing direction and a pulling direction between the first and second portions, whereby the angles formed by the respective ones of the first and second portions with respect to the joint can be kept identical to each other. Therefore, the respective ones of the first and second portions are operated symmetrically to each other with respect to the joint according to the present invention, whereby it is possible to avoid such a situation that the locking members are engaged in the open state locking concave portion or the closed state locking concave portion only in either one of the first and second portions. Namely, when the locking members are engaged in the open state locking concave portion or the closed state locking concave portion on either one of the first and second portions, the same are necessarily engaged in the other open state locking concave portion or closed state locking concave portion too. Due to such a fact, a complete locking state can be quickly attained in the grip bar both in the open state and the closed state of the baby carriage, without requiring a troublesome operation. Consequently, the grip bar encounters neither problem of safety nor problem of damage which may be caused since the baby carriage is used in an incomplete locking state.

Claims: A foldable grip bar for coupling a pair of push rods (2, 2) of a collapsible baby carriage and being adapted to enter a linear state in an open state of the baby carriage and to enter a folded state in a closed state of the baby carriage, said foldable grip bar comprising: a first portion (4) having an outer end rotatably supported by one of said pair of push rods (2) ; a second portion (5) having an outer end rotatably supported by another of said pair of push rods (2); a joint member (6) having one end rotatably connected to an inner end of said first portion (4) by means of a first rotary shaft (15) and having another end rotatably connected to an inner end of said second portion (5) by means of a second rotary shaft (16); a first open state locking concave portion (19) formed on said inner end of the first portion (4); a second open state locking concave portion (20) formed on said inner end of the second portion (5); a first closed state locking concave portion (21) formed on said inner end of the first portion (4); a second closed state locking concave portion (22) formed on said inner end of the second portion (5); a first locking member (23) movable in an axial direction of said first rotary shaft (15) to be engaged in said first open state locking concave portion (19) in the open state of the baby carriage and to be engaged in said first closed state locking concave portion (21) in the closed state of the baby carriage; a second locking member (24) movable in an axial direction of said second rotary shaft (16) to be engaged in said second open state locking concave portion (20) in the open state of the baby carriage and to be engaged in said second closed state locking concave portion (22) in the closed state of the baby carriage; springs (25, 26) for urging said first and second locking members (23, 24) into engagement with said concave portions (19, 20, 21, 22); and an unlocking member (27) for disengaging said locking members (23, 24) from said concave portions (19, 20, 21, 22) against the biasing of said springs (25, 26); characterised by a rigid link member (28) having one end portion rotatably mounted at a first position (29) on said inner end of the first portion (4) and having an opposing end portion rotatably mounted at a second position (30) on said inner end of the second portion (5), wherein an angle of a first straight line through said second position (30) and the axis of said second rotary shaft (16) with respect to a transversal straight line through the axis of said first rotary shaft (15) and the axis of said second rotary shaft (16) is  1 , and an angle of a second straight line through said first position (29) and the axis of said first rotary shaft (15) with respect to said transversal straight line is  2 , wherein angles  1 and  2 are on the same side of the transversal straight line and are exterior to the first straight line and the second straight line and wherein  1 is equal to  2 throughout folding and unfolding of the grip bar. A foldable grip bar in accordance with claim 1, wherein said open state locking concave portions and said closed state locking concave portions are formed from a common concave polygonally shaped portion.

Inventors: ONISHI ICHIRO, ONISHI, ICHIRO, ONISHI, Ichiro Aprica Kassai Kabushikikaisha
Applicants: APRICA KASSAI KK, APRICA KASSAI KABUSHIKIKAISHA
Application year: 1995
Main classification: B62B9
IPC codes: B62B7, B62B9