Wheel stopping device

Wheels (11, 11a) which are rotatably attached, for example, to the two rear legs (3, 3a) of a baby carriage, are brought into a stopped or locked state or the rotation of the wheels is permitted by an operation of a single operating member (25). Wheel stopping mechanisms (11, 11a) respectively associated with the wheels (11, 11a), are interlocked by a wire (26) for transmitting the operation of an operating member from one wheel stopping mechanism to the other.

BACKGROUND OF THE INVENTION 
This invention relates to a wheel stopping device and particularly to 
improvements in a wheel stopping device constructed to be attached to 
wheels of a baby carriage, for example, for selectively maintaining the 
stopped state. 
A baby carriage, for example, is desirably provided with a wheel stopping 
device whereby the baby carriage is inhibited from starting to move under 
its own weight as on a sloping road. It is desired that such wheel 
stopping device, which is manipulated as needed be simple in operation. 
Further, the wheel stopping device is closely related to the safety of 
baby carriages, and it is desirable that it be constructed so that with 
respect to baby carriage wheels disposed at two different places, e.g., 
right and left rear wheels, the device is capable of maintaining the 
stopped state of the wheels. This is even a legal obligation in some 
countries. 
In the case where the wheel stopping device is constructed to act on wheels 
disposed at two different places, it is desirable if two such wheel 
stopping mechanisms disposed at two places can be simultaneously actuated 
in one operation. When two wheel stopping mechanisms at two places are to 
be simultaneously actuated, a solution would be to connect them together 
by a suitable interlocking mechanism. However, if such wheel stopping 
device is attached to a collapsible baby carriage, the positional relation 
between the two wheel stopping mechanisms can change with the collapsing 
operation. In such case, the interlocking mechanism connecting the two 
wheel stopping mechanisms can interfere with the collapsing movement of 
the baby carriage; thus, some measure or other must be taken also for such 
interlocking mechanism. 
SUMMARY OF THE INVENTION 
Accordingly, an object of this invention is to provide a wheel stopping 
device wherein in the case where two wheel stopping mechanisms are 
provided at two places, such wheel stopping mechanisms can be 
simultaneously actuated in one operation and the interlocking mechanism 
for the two wheel stopping mechanisms does not interfere with the change 
in the relative positional relation between the two wheels caused by the 
collapsing movement of a baby carriage or the like. 
In this invention, there is employed an arrangement including first and 
second engaging shafts movable in parallel relation to the respective 
axles of first and second wheels disposed at two different places, and 
first and second ribs extending from the respective lateral surfaces of 
the first and second wheels, wherein when the first and second engaging 
shafts are moved toward the first and second ribs for engaging these ribs 
, respectively, the wheel stopped state is established. Therefore, the 
wheel rotation permitting state will be obtained by moving the engaging 
shafts away from the respective ribs. More particularly, the first and 
second engaging shafts are connected to one of the respective ends of 
first and second L-levers rotatably supported at first and second wheel 
attaching members for attaching the first and second wheels. An operating 
member is movably attached to the first wheel attaching member so that it 
abuts against the other end of the first L-lever, while the first L-lever 
is provided with a first spring which urges the first L-lever against the 
operating member. Thus, with the movement of the operating member, the 
first L-lever is turned while the first engaging shaft is moved toward and 
away from the first rib. A wire is used to interlock the two wheel 
stopping mechanisms. This wire is connected between the operating member 
and the second L-lever, whereby, the movement of the operating member is 
transmitted to the second L-lever, whereby, while the second L-lever is 
turned, the second engaging shaft is moved toward and away from the second 
rib in synchronism with the first engaging shaft. The second L-lever is 
provided with a second spring which urges the second L-lever in the 
direction which imparts tension to the wire. 
When the operating member is moved in the direction which turns the first 
L-lever against the resilience of the first spring, the first engaging 
shaft is moved away from the first rib, while the force transmitted 
through the wire turns the second L-lever against the resilience of the 
second spring, moving the second engaging shaft away from the second rib, 
whereby the wheel rotation permitting state is established. Since this 
wheel rotation permitting state must be maintained against the resilience 
of the second spring, a lock member is provided for locking the operating 
member to prevent the latter from moving relative to the first wheel 
attaching member. 
On the other hand, when the locking by the lock member is canceled, the 
first and second engaging shafts are moved toward the first and second 
ribs by the action of the first and second springs, whereby the wheel 
stopping state is established. 
According to this invention, since the first and second engaging shafts 
adapted to act on the respective ribs of the first and second wheels are 
interlocked by a wire through two L-levers and one operating member, by 
operating the single operating member it is possible to move the first and 
second engaging shafts in synchronism with each other toward or away from 
the ribs. Thus, the wheel stopping mechanisms disposed at two places can 
be simultaneously actuated in a single operation and hence the operations 
for obtaining the wheel stopped state and the wheel rotation permitted 
state are facilitated. Further, since the means for connecting the two 
wheel stopping mechanisms is a wire, there is no possibility of 
interfering with the change in the relative positional relation between 
the two wheel stopping mechanisms and hence between the first and second 
wheels disposed at two different places. Thus, this invention can be 
advantageously applied to collapsible baby carriages and the like. 
According to another aspect of this invention, there is provided a 
cushioning device for the wheels of a baby carriage. 
This cushioning device is characterized by the use of a compression spring 
which is installed in a state in which it is protected from the outside. 
More particularly, basically it comprises fixed brackets rigidly attached 
to leg members of a baby carriage, cylindrical sections formed as portions 
of said fixed brackets and defining vertically extending bottom-opened 
spaces, wheel attaching members for holding the axles of wheels, slide 
portions formed as portions of the wheel attaching members and inserted 
from below into the spaces of the cylindrical sections so that they are 
vertically slidable, and coiled compression springs which exert resilient 
forces between the fixed brackets and the wheel attaching members. The 
space of each cylindrical section is closed at its upper end by an upper 
wall, the latter being formed with a throughgoing hole smaller in 
cross-section than said space and substantially aligned with the central 
axis of the space. The slide portion comprises a central rod adapted to 
have its upper end received in said throughgoing hole, a box portion 
formed around said central rod to define therebetween a top-opened 
bottom-closed space and disposed in contact with the inner peripheral 
surface of the cylindrical section, and a stopper for defining the 
terminal end of the downward movement of the central rod with the upper 
end of the central rod received in said throughgoing hole, the arrangement 
being such that when the central rod is brought to the terminal end 
position in its downward movement, a clearance of predetermined height 
allowing a cushioning movement is formed between the upper end of the box 
portion and the lower surface of the upper wall. The compression spring is 
disposed with its lower end positioned between the central rod and the box 
portion and with its upper end contacting the lower surface of the upper 
wall. 
According to this cushioning device, a compression spring is used and since 
it is received in the space defined by the cylindrical section and the 
slide portion, the compression spring is protected against outside 
influences and hence will not suffer such troubles as rusting and dirt 
sticking thereto. Therefore, the cushioning device has a long useful life 
and the cushioning operation is stabilized. Further, since a long 
compression spring can be used without encountering such problems as 
aesthetic degradation and fingers being pinched, the cushioning 
performance can be enhanced even if a thick spring is used. The use of a 
thick spring makes it possible to lengthen the life of the device. 
Further, even if the compression spring should break, this will not lead 
to a serious accident, since the occurrence of such breakage is only 
between the cylindrical section and the slide portion while the latter is 
supported by the former; thus, the device is superior also in safety. 
Further, the fixed brackets and the wheel attaching members can be easily 
made of resin materials.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The wheel stopping device of this invention is applicable to various types 
of baby carriages and to any other vehicles and the like having wheels in 
at least two places. In addition, the embodiment to be described below is 
an application to a baby carriage having two rear legs. FIG. 15 shows an 
example of such baby carriage. 
The wheel stopping device of this invention, in a baby carriage having two 
front legs 103 and 103a and two rear legs 3 and 3a, for example, can be 
installed in connection with a pair of wheels including right and left 
front wheels, or including right and left rear wheels or including left 
front and rear wheels, or including right front and rear wheels. However, 
for the convenience of operation it is preferable to provide the wheel 
stopping device in connection with the wheels mounted on the rear legs 103 
and 103a. 
FIGS. 1 to 4 show a region around the lower end of one rear leg of the baby 
carriage shown in FIG. 15, e.g., the right-hand rear leg 3. In these 
figures, a cushioning mechanism 1 installed in connection with the wheel 
stopping mechanism, is mainly shown, the wheel stopping mechanism 2 being 
attached to the rear of the cushioning mechanism 1. As for the wheel 
stopping mechanism 2, only its external appearance is shown, the details 
of its construction being shown in FIGS. 5 to 14 to be described below. 
A fixed bracket 4 molded of resin is attached to the lower end of the 
right-hand rear leg 3 by a fixing pin 5. The rear of the fixed bracket 4 
has a vertically extending tubular section 6. The cross-sectional shape of 
the inner surface of the tubular section 6, as shown in FIG. 3, is 
substantially square. The upper end of the tubular section 6 is closed by 
an upper wall 7 having a throughgoing hole 8. The lower end of the tubular 
section 6 is completely open. The rear lower portion of the tubular 
section 6 has a notch 9. Further, the inner surface of the tubular section 
6, as shown in FIG. 3, has a plurality of ridges 10. 
The right-hand rear wheel 11 shown in a dash-dot line in FIGS. 1, 2, and 4 
is the outer one of the two wheels attached to the rear leg 3 shown in 
FIG. 15. These two wheels are rotatably supported on an axle 12, but the 
inner wheel is omitted from illustration except in FIG. 15. The axle 12 is 
held by a right-hand wheel attaching member 13, which is molded of resin 
and has two separate portions. That is, the front portion of the 
right-hand wheel attaching member 13 forms a slide portion for imparting a 
cushioning action. The axle 12 is positioned on the slide portion 14 
having a section received in the tubular section 6 of said fixed bracket 
4, said portion having a central rod 15 of circular cross-section, and a 
box portion 16 formed therearound, with a cylindrical space defined 
therebetween. The height of the central rod 15 is so selected that it is 
received in the throughgoing hole 8. The height of the box portion 16 is 
so selected that it forms a clearance of predetermined height between it 
and the upper wall 7 of the fixed bracket 4. This height allows the 
cushioning action. The outer peripheral surface of the box portion 16 is 
similar in shape to the inner surface of the tubular section 6 and has 
vertically extending grooves 17 for receiving the ridges 10. The slide 
portion 14 has a boss 18 projecting therefrom for receiving the axle 12 
therein. The notch 9 enables the boss portion 18 to avoid interfering with 
the vertical movement of the slide portion 14. An L-shaped engaging piece 
19 extends rearwardly from the lower end of the boss 18 of the slide 
portion 14. 
The rear portion of the right-hand attaching member 13 comprises a holding 
case 20 for holding the wheel stopping mechanism 2. The holding case 20 is 
mechanically integrated with the slide portion 14 in that its groove 21 
formed in the bottom receives said engaging piece 19 while its attaching 
piece 22 extending forwardly from the upper end thereof is fixed to the 
upper end of said central rod 15 by a screw 23. The construction of the 
wheel stopping mechanism installed in connection with the holding case 20 
will be described below with reference to FIG. 5 et seq. 
A compression spring 24 is disposed in the tubular section 6 of said fixed 
bracket 4 as it is positioned between the central rod 15 of the slide 
portion 14 and the box portion 16. The compression spring 24 serves to 
constantly downwardly urge the slide portion 14 and hence the right-hand 
side wheel attaching member 13 with respect to the fixed bracket 4, the 
terminal end of the downward movement thereof being defined by the 
attaching piece 22 on the holding case 20 abutting against the upper wall 
7 of the fixed bracket 4. 
In the case shown in FIGS. 1 and 2 there is no compression force acting 
between the right-hand rear wheel 11 and the right-hand rear leg 3 or, if 
a compression force is acting therebetween, it is overcome by the 
resilient force of the compression spring 24. In this case, the attaching 
piece 22 is abutting against the upper wall 7 and the structure including 
the right-hand rear wheel 11, axle 12 and right-hand side wheel attaching 
member 13 is placed at the lowermost position relative to the structure 
including the right-hand rear leg 3 and the fixed bracket 4. 
FIG. 4 shows a state where a force enough to compress the compression 
spring 24 is applied by the right-hand rear wheel 11 to the right-hand 
rear leg 3 and where the structure including the right-hand rear wheel 11, 
axle 12 and right-hand wheel attaching member 13 has been moved upwardly 
relative to the structure including the right-hand rear leg 3 and fixed 
bracket 4. Thus, the movement produced between the state shown in FIGS. 1 
and 2 and the state shown in FIG. 4 brings about a cushioning action. 
The wheel stopping device forming the essence of this invention will now be 
described. Referring to FIG. 5, an operating member 25 is provided on the 
side associated with the right-hand rear leg 3, and the right and left 
wheel stopping mechanisms are interlocked by a wire 26 adapted to be 
operated by moving said operating member 25. 
The holding case 20 forming part of the aforesaid right-hand side wheel 
attaching member 13 is provided with a pin 29 on which the right-hand 
L-lever 28 is rotatably supported. One end of the right-hand L-lever 28 
has an elongated opening 30 which receives a connecting pin 31 projecting 
from the end of the right-hand side engaging shaft 27. The right-hand 
engaging shaft 27 is received in a sleeve 32 on the holding case 20 and is 
held so that it is movable in a direction parallel to the axle 12. The 
right-hand engaging shaft 27 has a ridge 33 (FIG. 7) extending lengthwise 
thereof, while the sleeve 32 has a groove (not shown) extending throughout 
the length of the sleeve 32 to receive said ridge 33. A respective 
arrangement is provided on the left side including a projection 33a on the 
left-hand engaging shaft 27a and the left-hand sleeve 32a. The ridges 33 
and 33a on the engaging shafts 27 and 27a and the grooves in the sleeves 
32 and 32a receiving these ridges, guide the engaging shafts 27 and 27a to 
assure a stable movement of the shafts 27, 27a in the sleeves 32 and 32a. 
The operating member 25 shown in FIG. 6 is installed so that it contacts 
the other end of the right-hand L-lever 28. The operating member 25 has a 
box-like portion in the upper region thereof. The opposite lateral walls 
of the box-like portion are provided with substantially triangular guide 
holes 34. Further, the front wall of the box-like portion has a vertically 
extending relatively long insertion port 35 for passing the wire 26 
therethrough. A locking pawl 36 projects forwardly of the front wall of 
the box-like portion. On the other hand, the lower portion of the 
operating member 25 is provided with a hook 37 for fixing the end of the 
wire 26. The lower end of the operating member 25 carries a guide shaft 38 
laterally projecting in opposite directions. 
The operating member 25 is installed so that it is held between the 
opposite lateral walls of the holding case 20. In this state, a shaft 39 
extending through the guide holes 34 is installed to span the space 
between the opposite lateral walls of the holding case 20. A pulley 40 is 
rotatably supported on the shaft 39 and the wire 26 is entrained around 
the pulley 40. The wire 26 extends through a sleeve 41 on the attaching 
piece 22. The wire 26 coming out of the sleeve 41 is preferably covered by 
a flexible tube 42. The end of the flexible tube 42 is inserted into the 
sleeve 41, where it is fixed. 
As shown in FIG. 1 etc. described above, the lower end of the holding case 
20 has a vertically extending guide cut 43 in which the respective ends of 
the guide shaft 38 of the operating member 25 are received for movement, 
whereby the operating member 25 is vertically movable relative to the 
holding case 20 by a distance corresponding to the range in which the 
shaft 39 is movable in the guide holes 34 and corresponding to the range 
in which the guide shaft 38 is movable in the guide cuts 43. 
The aforesaid right-hand L-lever 38 is urged by a right-hand torsion spring 
44 to abut against the operating member 25. The torsion spring 44 is held 
on the pin 29 and engaged at its ends respectively by the holding case 20 
and the other end of the right-hand L-lever 28. Therefore, the right-hand 
L-lever 28, in FIG. 7, is urged to turn counterclockwise around the axis 
of the pin 29, constantly applying an upward force to the operating member 
25. In order to maintain the operating member 25 in the lower position 
despite such force, the holding case 20 is provided with a locking recess 
45 for receiving the aforesaid pawl 36, as shown in FIG. 9. 
In FIGS. 9 and 10 show the details of the right-hand rear wheel 11, which 
is provided with a plurality of right-hand side ribs 46 projecting from 
the lateral surface thereof. As shown in FIG. 10, when the right-hand 
engaging shaft 27 is moved toward the right-hand ribs 46, the state where 
it engages a right-hand rib 46 is established. 
As shown in the lower half of FIG. 5, the left-hand wheel stopping 
mechanism 2a is not provided with a member corresponding to the operating 
member 25. Thus, the left-hand wheel stopping mechanism 2a is somewhat 
simpler in its arrangement. In addition, in describing the arrangement on 
the left-hand, the elements corresponding to those included in the 
right-hand arrangement are denoted by the same reference numerals as used 
in the description of the right-hand arrangement, plus the letter "a" and 
only those parts which differ will be described while avoiding repeating 
the same description. 
The wire 26 extending from the right-hand wheel stopping mechanism 2, as 
shown in FIGS. 12 to 14, is directly connected to the left-hand L-lever 
28a in the left-hand wheel stopping mechanism 2a. A left-hand torsion 
spring 44a is installed so that the left-hand L-lever 28a is rotated in a 
direction imparting tension to the wire 26. More specifically, the 
left-hand torsion spring 44a is held on the pin 29a, with its ends 
respectively engaging the holding case 20a and the left-hand L-lever 28a. 
A cover 47 is fitted to the holding case 20a. The lower end of the cover 
47 has a shaft 48 laterally projecting in opposite directions. The 
respective ends of the shaft 48 are received in the cutouts 49 in the 
lower end of the holding case 20a while the shaft 39a extends through the 
opposite lateral walls of the cover 47, whereby the cover 47 is fixed to 
the holding case 20a. 
Referring to all the figures that have been mentioned so far, the method of 
operating the wheel stopping device and the resulting movements of parts 
will now be described. 
FIGS. 5, 7, 8, 12, and 13 show the wheel rotation permitting state. In this 
state, the right-hand and left-hand engaging shafts 27 and 27a are not 
projecting out of the sleeves 32 and 32a and hence they are not engaged 
with ribs formed on the rear wheels, e.g., ribs 46 shown in FIG. 9. This 
state is established by resisting the resilient forces of the right-hand 
and left-hand torsion springs 44 and 44a, and in order to maintain this 
state, the locking pawl 36 of the operating member 25 is engaged in the 
locking recess 45 of the right-hand wheel attaching member 13. In this 
state, the wire 26, which is tensioned by the action of the left-hand side 
torsion spring 44a, is applying a pushing force, to the left as viewed in 
FIG. 5, to the operating member 25. Thus, the locking pawl 36 will not be 
disengaged from the locking recess 45 unless an external force is applied 
thereto. 
To change the aforesaid wheel rotation permitting state into the wheel 
stopping state, the operator puts, for example, a foot on the upper 
surface of the operating member 25 and moves it to the rear namely to the 
right as viewed in FIG. 5. In response thereto, the operating member 25 is 
moved by an amount corresponding to the range in which the shaft 39 can 
horizontally move within the guide holes 34. As a result, the locking pawl 
36 comes out of the locking recess 45. Then, since the right-hand side 
torsion spring 44 is pushing up the operating member 25 through the 
right-hand L-lever 28 while, at the same time, the left-hand torsion 
spring 44a is applying tension to the wire 26, and since this tension of 
the wire 26 acts upwardly at the end of the wire 26 because of the 
presence of the pulley 40, this force results in the operating member 25 
being pulled up, whereby the locking pawl 36 is disengaged from the 
locking recess 45. Thus, as soon as the foot is removed from the operating 
member 25 the latter is upwardly moved, so that the state shown in FIGS. 9 
and 10 is established. Consequently, as shown in FIGS. 10 and 11, the 
right-hand L-lever 28 is rotated following the movement of the operating 
member 25, so that the right-hand engaging shaft 27 connected to one end 
thereof is projected out of the sleeve 32. In this state, as shown in FIG. 
10, the right-hand engaging shaft 27 engages the rib 46 thereby locking 
the rear wheel 11 against rotation. 
On the other hand, in the left-hand region, the aforesaid upward movement 
of the operating member 25 causes the wire 26 to move a predetermined 
distance toward the left-hand wheel stopping mechanism 2a. At this time, 
since a tension is constantly applied to the wire 26 by the left-hand 
torsion spring 44a, the left-hand L-lever 28 is rotated following the 
movement of the wire 26, thus projecting the left-hand engaging shaft 27a 
out of the sleeve 32a. Although the left-hand rear wheel is omitted in the 
figure showing the left-hand, it will be seen that when the left-hand 
engaging shaft 27a is projected in this manner, it engages the rib on the 
left-hand wheel thereby also locking it against rotation. The left-hand 
rear wheel described herein may be understood to be the wheel indicated at 
11a in FIG. 15. 
To change such wheel stopping or locking state back into the wheel rotation 
permitting state, it is only necessary to downwardly push in the operating 
member 25. In response thereto, the locking pawl 36 engages the locking 
recess 45, whereby the wheel locking is removed and rotation is permited. 
While the invention has so far been described with reference to a 
particular embodiment thereof, this embodiment may be modified at various 
portions thereof. 
For example, the torsion springs 44 and 44a provided to the L-levers 28 and 
28a may be replaced by tension springs or compression springs. 
Whle the operating member 25 has been constructed so that in its movement, 
at least the upper portion thereof is movable not only up and down but 
also back and forth, it may be so constructed that it is movable only up 
and down. In this case, the shape of the locking means comprising the 
locking pawl 36 and the locking recess 45 would have to be more or less 
changed. For example, it would be necessary to reduce the extent of 
projection of the member corresponding to the locking pawl or to provide 
an elastically deformable portion in this locking member. 
Further, while the aforesaid embodiment has been provided with cushioning 
mechanisms 1 and 1a, such cushioning mechanisms are not essential, and the 
wheel attaching member and the rear leg may be fixedly connected together. 
While this invention is advantageously applicable to collapsible baby 
carriages and the like, it is applicable also to baby carriages and the 
like having no such collapsing function. 
Although the present invention has been described and illustrated in 
detail, it is clearly understood that the same is by way of illustration 
and example only and is not to be taken by way of limitation, the scope of 
the present invention being limited only by the terms of the appended 
claims.