WO2006136921A2

WO2006136921A2 - Foldable frame, particularly for pushchairs, prams or the like

Info

Publication number: WO2006136921A2
Application number: PCT/IB2006/001680
Authority: WO
Inventors: Ivan Tomasi; Roberto Gorza
Original assignee: L'inglesina Baby S.P.A.
Priority date: 2005-06-20
Filing date: 2006-06-16
Publication date: 2006-12-28
Also published as: WO2006136921A8; ITVR20050083A1; WO2006136921A3

Abstract

A foldable frame (1), particularly for pushchairs, prams and the like, comprising a supporting framework (2) which has two sides (3), which are mutually interconnected by an articulated structure, each side having a rear upright (4b) and a front upright, associated with a respective handle tube, which are mutually articulated and associated in a downward region respectively with a front wheel assembly and a rear wheel assembly (5b), the supporting framework being adapted to pass from an extended or open condition to a collapsed or closed position and vice versa, reaction means (10) being provided which act between at least one pair of engagement elements (10a, 10b) of the supporting framework (2) which can move with respect to each other during the transition from the open condition to the closed condition and vice versa, the reaction means (10) being adapted to reverse the action applied to the at least one pair of engagement elements (10a, 10b) during the transition of the frame (1) from the open condition to the closed condition and vice versa.

Description

FOLDABLE FRAME₃ PARTICULARLY FOR PUSHCHAIRS, PRAMS

OR THE LIKE

TECHNICAL FIELD

The present invention relates to a foldable frame particularly for pushchairs, prams or the like.

BACKGROUND ART

As is known, frames for pushchairs and prams are currently widely used which can be folded so as to be able to pass from an extended (or open) condition, used to carry the child, to a collapsed (or closed) condition, in which the frame occupies less space and accordingly is easier to transport.

The most widely used foldable frames include those commonly known as "umbrella-folding" due to the particular manner in which they close. Such pushchair frames in fact fold both transversely and longitudinally (therefore along three dimensions) until they assume, when closed, a shape which can be likened to the shape of a closed umbrella.

There are also foldable frames with a so-called "flat" closure, which fold only in a longitudinal direction (along two dimensions). In greater detail, a foldable frame is constituted by a supporting framework, which comprises two lateral sides, each of which is constituted at least by two uprights (front and rear ones), which support rotatably a wheel or a wheel assembly; the front uprights are further associated with a respective handle tube, which supports a handgrip (or handle) at one of its ends.

The front uprights and the rear uprights are mutually articulated in order to allow the frame to pass, as mentioned earlier, from the extended condition to the collapsed condition.

Usually, the handle tubes of one side are connected to the rear uprights of the other side by means of a crosspiece (commonly known as lower crosspiece), which during use is arranged below the structure suitable to accommodate the child to be carried.

As regards in particular umbrella-folding frames, the supporting framework has, between the two rear uprights, two pivoted parallelograms, which are designed to allow the mutual approach and spacing, in a parallel manner, of the sides during transition from the extended condition to the collapsed condition and vice versa.

Such foldable frames, and in particular umbrella-folding frames, are very convenient in use, since they ensure rapid transition from the collapsed condition to the extended condition and vice versa and further occupy an extremely limited amount of space in the collapsed condition.

However, both types of frame (flat-folding and umbrella-folding), due to the presence of the particular (and complex) supporting framework, are often heavy and in some cases opening and closure operations are difficult. For example, for umbrella-folding frames, the large number of mutually articulated elements (lower crosspiece, double rear parallelogram, front and rear uprights and handle tubes) cause a certain difficulty in ensuring complete opening and/or closure of the frame. Such frames in fact have means for locking in the extended condition and/or in the collapsed condition, but such locking means are activated only if these conditions are actually reached. Often, instead, due to the reasons described above, complete opening and/or closure of the frame is not achieved, with the consequence that the locking means are not activated, to the- detriment of convenience of use (the user is forced to act again on the frame in order to complete closure and/or opening) and especially of safety.

In order to try to obviate these drawbacks, frames for pushchairs have been devised which are provided with reaction means, which are usually arranged at the double parallelogram for connection between the rear uprights of the two sides. An exemplary embodiment of said frames is disclosed in Italian utility model application no. MI1993U00465, filed June 7, 1993.

In this case, the reaction means (which can be constituted by helical springs or pneumatic springs) are adapted to push the rods with which they are associated in the direction of maximum extension of the parallelogram, so as to bring the frame to the fully extended condition.

Although these solutions allow to have an appreciable use of the pushchair during the opening, they are not devoid of drawbacks.

It should in fact be noted that on the one hand the use of springs or similar elements, especially at the double parallelogram, can be complicated from a constructive standpoint and secondly that said frames ensure exclusively a facilitation during the transition of the frame from the collapsed condition to the extended condition. DISCLOSURE OF THE INVENTION

The aim of the present invention is to eliminate or at least reduce drastically the drawbacks noted above in currently commercially available frames for pushchairs, prams and the like.

Within this aim, an object, of the present invention is to provide a foldable frame that ensures simplification of the opening and closure operations. Another object of the invention is to provide a foldable frame that can be used easily and offers the greatest assurances of reliability and safety in operation.

Another object of the invention is to provide a foldable frame that is constructively very simple and has a low production cost, so as to make its use advantageous also from an economical standpoint.

This aim and these and other objects, which will become better apparent hereinafter, are achieved by a foldable frame, particularly for pushchairs, prams and the like, according to the invention, comprising a supporting framework which has two sides, which are mutually interconnected by an articulated structure, each side having a rear upright and a front upright, associated with a respective handle tube, which are mutually articulated and associated in a downward region respectively with a front wheel assembly and a rear wheel assembly, said supporting framework being adapted to pass from an extended or open condition to a collapsed or closed position and vice versa, characterized in that it comprises reaction means, which act between at least one pair of engagement elements of said supporting framework which can move with respect to each other during the transition from said open condition to said closed condition and vice versa, said reaction means being adapted to reverse the action applied to said at least one pair of engagement elements during the transition of said frame from said open condition to said closed condition and vice versa.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages will become better apparent from the description of some preferred but not exclusive embodiments of the foldable frame according to the invention, illustrated by way of non- limiting example in the accompanying drawings, wherein:

Figure 1 is a rear elevation view of an umbrella-folding frame in the extended condition; Figure 2 is another rear elevation view of the umbrella-folding frame of Figure 1 in a closed position;

Figure 3 is a side elevation view of a pushchair frame in the extended condition;

Figure 4 is an enlarged-scale view of the reaction means associated with the frame shown in Figure 3 ;

Figure 5 is a side elevation view of a pushchair frame in an intermediate condition;

Figure 6 is an enlarged-scale view of the reaction means associated with the frame shown in Figure 5; Figure 7 is a side elevation view of a pushchair frame in the collapsed condition;

Figure 8 is an enlarged-scale view of the reaction means associated with the frame shown in Figure 7;

Figure 9 is a side elevation view of the lower portion of the front upright and of the handle tube of a pushchair frame in the .extended condition;

Figure 10 is an enlarged-scale view of the reaction means associated with the frame shown in Figure 9;

Figure 11 is a side elevation view of the lower portion of the front upright and of the handle tube of a pushchair frame in an intermediate condition;

Figure 12 is an enlarged-scale view of the reaction means associated with the frame shown in Figure 11 ;

Figure 13 is a side elevation view of the lower portion of the front upright and of the handle tube of a pushchair frame in the collapsed condition;

Figure 14 is an enlarged-scale view of the reaction means associated with the frame shown in Figure 13;

Figure 15 is a top view of the central portions of the lower crosspiece in the extended condition and with the reaction means associated therewith;

Figure 16 is a view, similar to Figure 15, of the central portions of the lower crosspiece in an intermediate condition and with the reaction means associated therewith;

Figure 17 is a view, similar to Figures 15 and 16, of the central portions of the lower crosspiece in the collapsed condition and with the reaction means associated therewith;

Figure 18 is a transverse sectional view of the crosspiece at the engagement portions of the reaction means;

Figure 19 is a side elevation view of a foldable frame, which is provided with the reaction means that act between the rear upright and the side tube;

Figure 20 is a view, similar to Figure 19, in which the reaction means that act between the rear uprights and a respective supporting tube or box holder are instead shown schematically; Figure 21 is again a side elevation view of a foldable frame in which the reaction means are arranged between the articulation assembly and the rear uprights;

Figure 22 is a side elevation view of a foldable frame in the extended condition, in which the reaction means are constituted by a pneumatic piston which acts between the rear uprights and the front uprights; and

Figure 23 is again a side elevation view of the foldable frame shown in Figure 22, but in the collapsed condition. WAYS OF CARRYING OUT THE INVENTION

In the exemplary embodiments that follow, individual characteristics, given in relation to specific examples, may actually be interchanged with other different characteristics that exist in other exemplary embodiments.

Moreover, it is noted that anything found to be already known during the patenting process is understood not to be claimed and to be the subject of a disclaimer. With reference to the figures cited above, a foldable frame particularly for pushchairs, prams and the like, generally designated by the reference numeral 1, comprises a supporting framework 2 provided with two sides 3.

The two sides 3 are mutually connected by an articulated structure, and each side has a rear upright 4b and a front upright 4a.

The front uprights 4a and the rear uprights 4b are mutually articulated

(for example about an articulation assembly 4c) and are associated in a downward region, respectively, with a front wheel assembly 5 a and a rear wheel assembly 5b. In particular, each of the two sides 3 comprises a handle tube 4e, which as explained better hereinafter, during the transition from the open condition to the closed condition, can move with a combined rotary and translational motion with respect to the respective front upright 4a.

Conveniently, In order to ensure a correct path of the handle tube 4e with respect to the respective front upright 4a, there is a guiding linkage 4d, which is connected rotatably to a respective articulation portion, which is arranged substantially at the lower end portion of the handle tube 4e and of the front upright 4a.

In particular, as mentioned, the supporting framework 2 (and with it the foldable frame 1) is adapted to pass from an extended or open condition (as shown in Figures 1 and 3) to a collapsed or closed position (shown in Figures 2, 7 and 13) and vice versa.

According to the present invention, the foldable frame 1 comprises reaction means 10, which act between at least one pair of engagement elements 10a, 10b, which are part of the supporting framework 2; said engagement elements 10a, 10b can move with respect to each other during the transition of the framework 2 (and therefore of the foldable frame 1) from the open (or extended) condition to the closed (or collapsed) condition and vice versa. In particular, the reaction means 10 are adapted to reverse the direction of the action applied to the respective pair of engagement elements 10a, 10b during the transition of the foldable frame 1 (and of the supporting framework 2) from the open condition to the closed condition and vice versa. Conveniently, the reaction means 10 can be adapted to apply to the engagement elements 10a, 10b an action that tends to open the supporting framework 2 (and therefore the frame 1) when it is proximate to the open condition and to close the supporting framework 2 (and therefore the frame 1) when it is proximate to the closed condition. In greater detail, the engagement elements 10a and 10b associated with the reaction means 10 can rotate with respect to each other about a pivoting node 20 during the transition of the supporting framework 2 from the open condition to the closed condition and vice versa.

Advantageously, the reaction means. 10, during transition from the open condition to the closed condition and vice versa, are adapted to reverse the thrust on the engagement elements 10a and 10b; this thrust reversal in practice is converted into a reversal of the torque generated on each of the two engagement elements 10a and 10b about the pivoting node 20 by the force applied to the -engagement elements 10a and 10b and represented schematically in Figures 15 to 17 by the arrow designated by the letter F.

With particular reference to so-called umbrella-folding frames, the articulated structure 4 comprises a plurality of rod-like elements 11, which are mutually articulated and form a double parallelogram 12 for connection between the two rear uprights 4b of the two sides 3. As shown in Figures 1 and 2, when the foldable frame 1 is in the open condition, the double parallelogram 12 is extended, while when the foldable frame 1 is in the closed condition, the double parallelogram 12 is folded.

Advantageously, the engagement elements 10a, 10b associated with the reaction means 10 can be able to rotate with respect to each other about a pivoting node 20 during transition from the open condition to the closed condition and vice versa.

According to a first embodiment (shown in Figures 3 to 8 and 15 to 17), the reaction means 10 can be constituted by a trap spring 100, the pusher ends whereof engage a respective portion of the engagement elements 10a, 10b.

As an alternative, it is possible to provide (as shown in Figures 9 to 14) reaction means 10 which comprise a cam device 200 provided with a device body 201 which is rigidly coupled to one of the engagement elements 10a and a movable head 202 which acts on the other engagement element 10b. With reference instead to the embodiment shown in Figures 1 and 2, the reaction means can be constituted by a flat spring 300, the pusher ends whereof engage a respective portion_of the engagement elements 10a, 10b. Again with reference to the embodiment shown in Figures 1 and 2, the two engagement elements 10a and 10b can comprise a first rod-like element and a second rod-like element 11, which are mutually articulated and belong to the- double parallelogram 12 for connection between the two sides 3. In particular, the two engagement elements 10a and 10b can comprise the rod-like elements 11, which constitute the lower sides of the double- parallelogram 12: in this case, the pivoting node 20 corresponds to the central lower node of the double parallelogram 12.

Of course, there is nothing to prevent the pair of engagement elements 10a and 10b from being constituted by rod-like elements 11 which constitute the upper sides of the double parallelogram 12 or, again, by rod- like elements that constitute the lower or upper sides of the double parallelogram 12 and the rear uprights 4b associated therewith.

The articulated structure of umbrella-folding pushchairs further generally comprises a lower crosspiece 15, which comprises a pair of rods 15a and 15b for mutual connection between the rear upright 4b of one side 3 and the handle tube 4e related to the other side 3.

With reference to Figures 15 to 17, which illustrate the central portions (which are mutually pivoted) of the mutual connection rods 15a and 15b of the lower crosspiece 15, it can be noted that the reaction means 10 act on engagement portions formed on a respective connecting rod 15a and 15b of the lower crosspiece 15.

Analyzing in detail this embodiment (in which the reaction means 10 are obtained by using a so-called trap spring 100), it can be seen that in a condition of the foldable frame 1 that is proximate to the open condition (shown in Figure 15), the two arms 100b of the trap spring 100 (which tend to always apply a force that is directed away from the spiral 100a) generate on said engagement elements 10a and 10b a thrusting action, which leads to a torque on the engagement elements 10a and 10b (constituted in the illustrated example by the mutual connection rods 15a and 15b) about the pivoting node 20, said torque tending to open the angle formed between said engagement elements 10a and- 1 Ob .

During the transition from the open condition to the closed condition, the reaction means 10 are arranged in the intermediate position shown in the example of Figure 16, in which in particular the straight line of action of the force F (in practice, the straight line that passes through the connecting points between the arms 100b and the respective engagement element 10a and 10b) passes through the pivoting node 20: in this case, the torque generated by the reaction means 10 on the engagement elements 10a and 10b (in this particular case, on the mutual connection rods 15a and 15b) about the pivoting node 20 is nil, since the connecting points of the two arms 100b with the respective engagement element 10a and 10b are aligned with the center of relative rotation (or pivoting node 20) between the two rods for mutual connection 15a and 15b (in practice, the torques are zero, since the arms related to the forces F about the pivoting node 20 are equal to zero). As the supporting structure 2 and, in this case, the lower crosspiece

15, move toward the closed condition (as shown in Figure 17), it can be seen that the action of the thrust generated by the forces F on the engagement elements 10a and 10b leads to a torque about the pivoting node 20 which tends to close the angle formed between said engagement elements 10a and 10b, so as to assist the user during the frame closure operations.

In summary, during the transition from the open or extended condition to the closed or collapsed condition, the straight line of application of the forces F (generated by the reaction means 10) changes its position, passing from a position in which said reaction means 10 are adapted to push against the respective engagement elements 10a and 10b so as to move the frame toward the open condition to a position in which they tend to push against the respective engagement elements 10a and 10b so as to move the frame toward the closed condition. The reversal, of the pushing action is achieved (if, as shown in the various embodiments, the engagement elements 10a and 10b are rotatably articulated about a respective pivoting node 20) when said straight line of application of the forces F passes through said pivoting node 20.

According to another constructive variation, the engagement elements 10a and 10b can be constituted by at least one guiding, linkage 4d and by the handle tube 4e articulated thereto, or, equivalently, by at least one guiding linkage 4d and by the front upright 4a that is articulated thereto (as shown in Figures 3 to 12).

Conveniently, if the reaction means 10 are positioned at the sides 3 or at lateral regions of the double parallelogram 12, the reaction means 10 act on pairs of engagement elements 10a and 10b which are advantageously arranged symmetrically with respect to the longitudinal plane of symmetry of the foldable frame 1, such as for example in the examples shown in Figures 19 to 21. Of course, as clearly shown in the figures listed above, the reaction means 10 can be placed in various positions and in particular at rod-like elements 11, which constitute the double rear parallelogram, at the connecting rods 15a and 15b that constitute the lower crosspiece 15, between the rear uprights and the respective articulation assembly 4c, between the rear upright and the respective side tube, et cetera.

Operation of the foldable frame according to the present invention is evident from what has been described above.

In particular, if the user wishes to move the foldable frame 1 from the closed condition to the open condition, during a first step of this transition he has to overcome not only the friction produced by the relative movements of the elements that constitute the supporting framework but also a thrust that contrasts this movement and is applied by the reaction means to the respective engagement elements; once the dead center or thrust reversal point (shown merely by way of example in Figure 16) has been passed, the reaction means 10 reverse the thrust, assisting the user in completing the transition of the foldable frame 1 from the closed condition to the open condition and accordingly ensuring the complete extension of the supporting framework 2 and the mutual locking of the uprights (front and rear) and the handle- tube. The same occurs if the user wishes to move the foldable frame 1 from the open condition to the closed condition: in a first step, he has to overcome the contrasting thrust (applied by the reaction means to the respective engagement elements), but then, after passing beyond the dead center or thrust reversal point, the reaction means tend to push so as to move the supporting framework (and therefore the foldable frame) into the closed condition.

All the characteristics of the invention indicated above as advantageous, convenient or the like may also be omitted or be replaced with equivalents. The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept.

In particular, it is possible to provide, at the rod-like elements that constitute the engagement elements 10a and 10b, a plurality of engagement points for the reaction means 10, so as to be able to vary at will the position of the thrust reversal point of said reaction means 10.

It is further possible to also use a number of reaction means 10 in which the respective thrust reversal points are at different positions along the transition from the open condition to the closed condition: for example, it is possible to provide two or more reaction means, which have a dead center or thrust reversal point arranged in different intermediate positions between the collapsed condition and the extended condition.

Moreover, it has also been found that in some applications it can be advantageous to have reaction means 10 of different types on the same frame: merely by way of example, it is possible to provide a trap spring which acts at the linkage and has a thrust reversal point arranged in such a way as to facilitate particularly the frame closure operations and at the same time a flat spring which acts at the double parallelogram and has a thrust reversal point located so as to facilitate in particular the frame opening operations.

Moreover, as clearly shown in the exemplary embodiment of Figures 22 and 23, there is nothing to prevent the. reaction means from being constituted by one or more pneumatic pistons 400, the respective body 401 and stem 402 whereof are associated rotatably with the various types of engagement elements 10a and 10b.

In the illustrated example, the piston tends to act by pushing in order to move apart the engagement elements with which the piston body 401 and the stem 402 are associated, but nothing prevents the use of pistons 400 that apply traction between the two engagement elements. In practice it has been found that the invention has achieved the intended aim and objects in all of the embodiments.

In particular, it has been found that the placement and use of the reaction means, as shown in Figures 1 and 2 and 15 to 18, are particularly adapted to be used on umbrella-folding frames, while the ones shown in Figures 3 to 14 and 19 to 21 can be used on flat-folding frames but also on umbrella-folding frames.

Moreover, there is nothing to prevent the use of the reaction means described above and claimed on frames for pushchairs or the like with three wheels, of the type provided with two wheels (or rear wheels assemblies) and one front wheel (or wheel assembly), and in which the sides are associated with the same wheel or wheel assembly.

In practice, the materials used, as well as the dimensions, may be any according to requirements.

All the details may further be replaced with other technically equivalent elements.

Thus, for example, it has been found that the flat springs that can be used for this purpose can be of various kinds: mention is made, merely by way of example, of springs shaped so as to be elastically deformable: among the many, mention is made of metallic ones but also of those made of plastic material.

The disclosures in Italian Patent Application no. VR2005A000083, from which this application claims priority, are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A foldable frame, particularly for pushchairs, prams and the like, comprising a supporting framework which has two sides, which are mutually interconnected by an articulated structure, each side having a rear upright and a front upright, associated with a respective handle tube, which are mutually articulated and associated in a downward region respectively with a front wheel assembly and a rear wheel assembly, said supporting framework being adapted to pass from an extended or open condition to a collapsed or closed condition and vice versa, characterized in that it comprises reaction means, which act between at least one pair of engagement elements of said supporting framework which can move with respect to each other during the transition from said open condition to said closed condition and vice versa, said reaction means being adapted to reverse the action applied to said at least one pair of engagement elements during the transition of said supporting framework from said open condition to said closed condition and vice versa.

2. The foldable frame according to claim 1, characterized in that said reaction means are adapted to apply to the respective pair of engagement elements an action that tends to open said supporting framework proximate to said open condition and to apply an action that is adapted to close said supporting framework proximate to said closed condition.

3. The foldable frame according to one or more of the preceding claims, characterized in that the engagement elements associated with said reaction means can rotate with respect to each other about a pivoting node during the transition from said open condition to said closed condition and vice versa.

4. The foldable frame according to one or more of the preceding claims, characterized in that said reaction means, during the transition from said open condition to said closed condition, are adapted to reverse the thrust on said engagement elements about the respective pivoting node, so as to ensure reversal of the torque applied to said engagement elements around said pivoting node.

5. The. foldable frame according to one or more of the preceding claims, characterized in that said reaction means comprise a trap spring whose thrust ends engage a respective portion of said engagement elements.

6. The foldable frame according to one or more of the preceding claims, characterized in that said reaction means comprise a cam device which has a device body rigidly coupled to one of said engagement elements and a movable head which acts on the other engagement element.

7. The foldable frame according to one or more of the preceding claims, characterized in that said reaction means comprise a flat spring, whose thrust ends engage a respective portion of said engagement elements.

8. The foldable frame according to one or more of the preceding claims, characterized in that said reaction means comprise at least one pneumatic piston, which acts between said engagement elements.

9. The foldable frame according to one or more of the preceding claims, characterized in that said articulated structure comprises a plurality of rod-like elements, which are mutually articulated and form a double parallelogram for connection between the two rear uprights of said two sides, said double parallelogram being extended when said frame is in said open condition, said double parallelogram being folded when said frame is in said closed condition.

10. The foldable frame according to one or more of the preceding claims, characterized in that said at least one pair of engagement elements comprises a first rod-like element and a second rod-like element, which are mutually articulated and define part of said double connection parallelogram.

11. The foldable frame according to one or more of the preceding claims, characterized in that said articulated structure comprises a lower crosspiece, which comprises two rods for mutual connection between the rear upright of one side and the handle tube of the other side, said reaction means acting between engagement portions formed on a respective rod for the connection of said lower crosspiece.

12. The foldable frame according to one or more of the preceding claims, characterized in that each one of said sides comprises a handle tube, which can move with a rotary and translational motion with respect to the respective front upright, a guiding linkage being provided which is connected rotatably to a respective articulation portion, which is arranged substantially at the lower end portion of said handle tube and of said front upright, said engagement elements comprising at least one guiding linkage and the respective front upright or at least one guiding linkage and the .respective handle tube.

13. The foldable frame according to one or more of the preceding claims, characterized in that said reaction means act between at least two pairs of engagement elements.

14. The foldable frame according to one or more of the preceding claims, characterized in that said at least two pairs of engagement elements are arranged symmetrically with respect to the longitudinal plane of symmetry of said foldable frame.

15. The foldable frame according to one or more of the preceding claims, characterized in that it comprises at least two reaction means, which act respectively on a pair of engagement elements.

16. The foldable frame according to one or more of the preceding claims, characterized in that said at least two reaction means, which act respectively on two engagement elements, have a respective thrust reversal point which is arranged at a different intermediate condition of said foldable frame between said open condition and said closed condition.

17. The foldable frame according to one or more of the preceding claims, characterized in that said flat spring comprises a body which is shaped so as to be elastically deformable.

18. The foldable frame according to one or more of the preceding claims, characterized in that said flat spring is made of metallic or plastic material.