Foldable baby stroller chassis

A foldable baby stroller chassis includes a pair of front legs with a plate pivotally connected to the upper end of the legs and a pair of back legs having upper ends pivotally connected to the plate. A member is provided having a lower end with a clamp connection to the lower ends of the front legs and an upper bent arm portion with an intermediate pivotal connection to the back leg. A rear seat portion having an intermediate portion pivotally connected to the upper end of the bent arm portion and a plate, which is preferably triangular in shape, is connected to the rear seat portion adjacent its lower end and has an apex projecting forwardly in which a handle is connected pivotally. A joining plate is provided on each side of the upper end of the back legs and pivotally connected to the upper end of the front legs and the upper ends of the back legs. A bushing is carried on each side of a handle and extends and is movable relative to the handle. The bushing inlcudes a limit engagement hook and a limit stub arranged and spaced at locations along the handle. The stubs are selectively engageable with the hook portions of the bushing to position the chair in selected adjusted position either folded or extended. In addition, the construction includes an armrest assembly made of a covering material with a connection piece at each end which fits over and is connected to the upper end of the front legs and the upper end of the bent arm portion of the strut leg. The armrest portion has a slot into which a peg of a guardrail is insertable and the peg is lockable in the slot by a latch which may be released by a headpiece which may be pushed. The construction further includes a seat bottom which is pivoted on a cross piece of the front leg and connected to the rear seat portion and includes a footrest plate extending outwardly and downwardly from the front legs.

BACKGROUND OF THE INVENTION 
Field of the Invention 
This invention refers in general to foldable structures and in particular 
to a new and useful foldable chassis for baby strollers with front 
guardrails. 
The different types of chassis for baby strollers and the different types 
of folding systems they present have been well known here, there are those 
that juxtapose the handles and back against the armrests, seat, back and 
front legs, with folding and unfolding by moving the handles, pushing 
forward and downward or up and toward the back, respectively. 
The present invention is an improvement over Spanish Utility Model No. 
292,203 which refers to a chassis of this type, made up of a simple 
structure that is also comfortable for the child and at the same time is 
easy to fold and unfold. This chassis includes basically, on each side, 
the joint between the handle branch and the back leg via a bent arm that 
extends downward, to where it joins a strut whose other end is joined to 
the front leg. This leg is joined to the front side of the back leg by its 
upper part; the back leg is joined to a flatbar, which functions as an 
armrest and joins at the back end to the handle branch. 
SUMMARY OF THE INVENTION 
The present invention provides an improved construction with a more 
complete armrest that is more comfortable for the child and that gives the 
stroller a better finish. The chassis has also been given a handle with 
two positions, so that the stroller can be pushed with the seat facing the 
person who's pushing with the child's back to the direction in which the 
stroller is pushed, or with the child facing in the direction the stroller 
is pushed. With a special feature, the uncoupling of the handle is done 
manually and without any difficulty. The coupling in both positions is 
done automatically, by simply swinging the handle forward or toward the 
back. 
According to the invention, the rear joint of the armrest and the bent arm 
is made on a section at the rear of the chassis that substitutes for the 
handle branch, which is now joined further down at the bottom of this 
section. This, and the front end of the armrest, including both pivots on 
which the two handle positions are coupled via a bushing which is acted on 
elastically, and that slides along it and presents hooks in the front and 
the back respectively. 
The armrest is composed of a body like a long box where a core is housed. 
The core joins at its ends to the upper end of the rear section and that 
of the back leg. The back leg ends each have integrated pieces that, upon 
the unfolding of this stroller, cover both of the armrest openings. The 
back piece forms an anchoring element for a hook, while the front piece 
joins a plate to which a front leg is joined. The legs also supports an 
element for anchoring the front guardrail. 
The front piece totally blocks the corresponding opening in the armrest, 
and, in order to keep the child from hurting his fingers, by inserting 
them in the opening made for the anchoring of the guardrail, there is a 
blocking piece. This blocking piece includes a casing leaving a small 
space which is occupied by the protruding head of an elastic safety catch, 
juxtaposed with this casing. The safety catch has a tooth that penetrates 
this casing and catches in the opening of a peg that forms the finished 
end which is hinged to the front guardrail and is inserted, immobile, in 
the casing. 
Accordingly, it is an object of the invention to provide a foldable baby 
stroller chassis which may be locked in a folded and unfolded position and 
which includes an armrest assembly engaged between an upper bent arm 
portion of a strut which is clampable to the front legs into the upper 
ends of the front legs themselves. Construction includes a guardrail which 
may be engaged in and locked to each side of the stroller in the flat 
metal piece which is fitted over the front legs and has a latch therein 
for engagement with the guard piece. 
A further object of the invention is to provide a foldable baby stroller 
chassis which is simple in design, rugged in construction and economical 
to manufacture. 
The various features of novelty which characterize the invention are 
pointed out with particularity in the claims annexed to and forming a part 
of this disclosure. For a better understanding of the invention, its 
operating advantages and specific objects obtained by its uses, reference 
is made to the accompanying drawings and descriptive matter in which a 
preferred embodiment of the invention is illustrated.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to the drawings in particular, the invention embodied therein 
comprises a foldable baby stroller chassis which includes an armrest 16 
which is carried by pieces 25 and 26 which are engaged over the respective 
upper ends of front leg portions 11 and a rear seat portion 4 of the 
stroller according to the invention. 
This chassis includes a handle shaped like an inverted "U" 1 whose branches 
are joined at the bottom 2 of each side to a triangular plate 3 that is 
attached to a rear section 4 which, through an intermediate point 5, is 
connected to a joint with an intermediate point 6 of a back leg 7 through 
a bent arm 8. The bent arm 8 extends and joins a strut 9 that at its lower 
end joins a clamp 10 attached to the lower part of the front legs 11 that 
are provided, as are the back legs, with the corresponding wheels. 
The front legs 11 are joined near the top 12 to a plate 13 attached to the 
upper end of the back legs 7, which are joined through the plate 13 at the 
top 14 of the back sections 4 via a bent flatbar 15 that makes up the 
armrest 16. 
The branches of the handle include the sliding arrangement for both 
bushings 17 that form two opposing hooks 18 and 19, one in front and one 
in back, which permits the handle to be fixed in two positions; one front 
position (FIG. 1) and one back position (FIG. 2). The handle 7 is fastened 
when these hooks 18 or 19 are caught on a stub 20 provided on the side of 
the front end of the armrest 16 and a stub formed at the joining point 5 
of the rear piece 4, respectively. 
The bushing 17 moves vertically between two limits, a lower one, formed by 
an end-piece 21 on the branch of the handle, and another upper limit 22 
anchored to the branch of the handle 1, between whose limit and the bottom 
23 of the bushing there is a spring 24 (FIG. 3) that tends to push the 
bushing toward its low position (by urging the bracket downward), coupling 
them with the lower limiter. 
To change the handle from one position to the other only requires the 
manual elevation of the bushings 17 on each arm 1, uncoupling them from 
the stub 20 or 5, and when the handle is moved forward or toward the back, 
the bushings will be coupled automatically with the corresponding stub, 
the coupling being aided when the outside, oblique edges of the hooks 18 
and 19 collide with the stub, with the consequent compression of the 
spring 24. 
The armrest 16 comprises a molded body made of plastic material, in the 
form of a long box open underneath, along which there is a flatbar core 
15, on the ends of which both pieces 25 and 26 are attached and when the 
stroller is unfolded cover the respective openings 27 and 28 at the upper 
ends of the armrests, whose openings aid in the play of the end joints of 
the flatbar core mentioned earlier. 
Attached to the plate 13 there is a coupling piece 29 that protrudes from 
the opening 27 of the armrest, and is where a front guardrail is coupled 
immobilely, and the piece 26 forms a casing with a coupling tooth 30 on 
the outside for the same immobile coupling of a hood. 
The reference number 31 indicates the bottom of the seat which is supported 
by a U-shaped flatbar 32 that, at its ends, is joined to a point 33 on the 
back legs, and is supported in the front by a cross piece 34 that unites 
the front legs and constitutes the axle that supports a footrest plate 35. 
The stroller is completed by a backrest, joined to the back of the seat and 
by other complements and accessories typical of this type of stroller, as 
provided with the Spanish utility model No. 292,203 referred to at the 
beginning. 
According to the FIGS. 4, 5 and 6, the piece 25, molded in plastic 
material, is essentially flat and forms a casing 36 at the upper part, 
with an upper mouth 37 coinciding with a transversal upper fin 38 that 
coincides with the rectangular opening 27 of the upper, frontal part of 
the armrest 16, which is formed by a box with an inverted U-shaped 
section. 
Between this fin 38 and the opening 27 there is, in one of the angles, a 
small space that is occupied by a semi-elastic safety catch formed by a 
semi-elastic flatbar 29' juxtaposed with the outside surface of the piece 
25' and flatbar 29' presents a transversal bend 39 so that the tooth 40 
that the flatbar presents tends to enter in the interior of the casing 36 
through a window 41 in it, whose flatbar is finished with an exterior head 
42 for moving the safety catch that closes the opening between the fin and 
the opening. 
The indicated piece 25 is mounted with a joint on the inside of the armrest 
via an axle 43, and coupled to the inside surface of this piece, the metal 
plate 13 to which is attached the back leg 7 and the front leg 11. 
This device is completed with a coupling element provided at the ends of a 
front guardrail, which includes a core 44 (preferably made of various 
jointed sections) covered with a case 45 made of elastic sponge material. 
This coupling element comprises a flat peg 46 that has a drill-hole 47 and 
is jointed through a bolt 48 at the ends of the core mentioned before. 
The guardrail is coupled by inserting the pegs 46 in the casing 36, the 
teeth 41 preforating the elastic safety catch in the drill-holes 47 of the 
respective pegs. 
To uncouple the guardrail, one presses the heads 42 of the elastic safety 
catches to the side and outward, as the arrow F indicates (FIG. 6), by 
which the teeth 40 on the safety catch will be withdrawn from the 
drill-holes 47 and the pegs 46 with the guardrails can be withdrawn. 
The object of this invention, in its essence, can be put into practice in 
other ways that differ in detail from those indicated only by way of an 
example to which the protection being claimed will extend as well. This 
foldable baby stroller chassis will be able to be manufactured in whatever 
form or size, with the means and materials most adequate, and with the 
accessories that are most convenient, the components being able to be 
substituted by others that are technically equivalent, so that all of this 
is comprised in the spirit of the claims.