GB2379955A

GB2379955A - Pivot joint for a stroller frame

Info

Publication number: GB2379955A
Application number: GB0122848A
Authority: GB
Inventors: Lan Red
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-09-22
Filing date: 2001-09-22
Publication date: 2003-03-26
Anticipated expiration: 2021-09-22
Also published as: GB2379955B; GB0122848D0

Abstract

A pivot joint includes a stationary seat member 2 formed with a plurality of first grooves 223, a pivot seat member 3 formed with a plurality of second grooves 325 and coupled to the stationary seat member 2 to form a receiving space therebetween, a retaining member 63 disposed in the receiving space and formed with a plurality of teeth 634 engaging the first and second grooves 223, 325 and a first helical cam face 637, and an actuating unit including a rotary member 64 having a second helical cam face 644 which conforms to and which is in sliding contact with the first helical cam face 637 when the retaining member 63 is at a locking position. The rotary member 64 is turnable so as to move the second helical cam face 644 toward and away from the first helical cam face 637, which, in turn, moves the retaining member 63 from the locking position to an unlocking position where the teeth 634 disengage from the first grooves 223. The actuating unit further includes a string 70 connected to the rotary member 64 and having a pulling end 71 exposed from the pivot joint 10 for turning the rotary member 64.

Description

PIVOT JOINT FOR A STROLLER FRAME This invention relates to a pivot joint for a stroller frame, more particularly to a pivot joint that can be conveniently operated for adjusting the relative positions of interconnected frame portions.

A conventional pivot joint for a stroller frame for adjusting the relative positions of first and second frame portions connected thereto normally includes a stationary seat member connected to the first frame portion, and a pivot seat member connected to the second frame portion and coupled to and turnable relative to the stationary seat member. A retaining member is in constant engagement with the stationary seat member, and is movable between a locking position, in which, a toothed part of the retaining member interlocks a toothed part of the pivot seat member so as to prevent the pivot seat member from turning relative to the stationary seat member, and an unlocking position, in which, the toothed part of the retaining member disengages from the toothed part of the pivot seat member so as to permit turning of the pivot seat member relative to the stationary seat member.

U. S. PatentNo. 5,765, 958disclosesapivotjoint for a stroller frame with a retaining member that is

similar to the aforesaid retaining member, except that the toothed parts of the retaining member and the pivot

seat member form a cam mechanism when engaging each other so as to permit the pivot seat member to be turnable in a counterclockwise direction.

Disengagement of the above described retaining members from the respective pivot seat member is carried out by pushing the retaining member away from the pivot seat member against the action of an urging member. However, the pushing operation as such is not ergonomical.

Therefore, the object of the present invention is to provide a pivot joint for a stroller frame that is capable of overcoming the aforementioned drawback.

According to the present invention, there is provided a pivot joint that is adapted to interconnect first and second frame portions of a stroller frame. The pivot joint comprises: a stationary seat member adapted to be connected to the first frame portion of the stroller frame and having a first pivot part that defines a first cylindrical recess and that has a first annular inner face confining the first cylindrical recess and formed with a plurality of first grooves within the first cylindrical recess; a pivot

seat member adapted to be connected to the second frame portion of the stroller frame and having a second pivot part that defines a second cylindrical recess and that has a second annular inner face confining the second cylindrical recess and formed with a plurality of

second grooves within the second cylindrical recess, the pivot seat member and the stationary seat member being coaxially coupled to each other such that the first and second cylindrical recesses cooperate to form a receiving space ; a pivot pin extending through centers of the first and second cylindrical recesses so as to permit the pivot seat member to be turnable relative to the stationary seat member ; a retaining member in the form of a toothed wheel that is disposed in the receiving space around the pivot pin and that is formed with a plurality of teeth and at least a cam recess, the retaining member being movable along an axis that is defined by the pivot pin between a locking position, in which the teeth engage the first and second grooves, and an unlocking position, in which the teeth engage the second grooves and disengage the first grooves, the retaining member being formed with a first helical cam face in the cam recess, the first helical cam face extending helically and inwardly of the retaining member ; an urging member disposed in the receiving space for urging the retaining member to move to the locking position ; and an actuating unit including a rotary member disposed between the stationary seat member and the retaining member around the pivot pin and having a wheel portion and at least a cam protrusion that projects from the wheel portion into the cam recess and that is formed with a second

helical cam face which conforms to and which is in sliding contact with the first helical cam face when the retaining member is at the locking position. The rotary member is turnable about the pivot pin so as to move the second helical cam face toward and away from the first helical cam face, which, in turn, moves the retaining member from the locking position to the unlocking position. The actuating unit further includes a string having a fixed end that is connected to the wheel portion, and a pulling end that is exposed from the pivot joint so as to turn the wheel portion about the pivot pin, which, in turn, moves the retaining member from the locking position to the unlocking position, when the pulling end is pulled in a direction away from the pivot joint.

In drawings which illustrate an embodiment of the invention, Fig. 1 is a front perspective view of a stroller frame that incorporates a preferred embodiment of a pivot joint according to this invention; Fig. 2 is an exploded perspective view of the pivot joint to be connected to first and second frame portions of the stroller frame of Fig. 1; Fig. 3 is a sectional view to illustrate a locking position of a retaining member in a receiving space of the pivot joint of Fig. 2; Fig. 4 is an exploded perspective view to

illustrate engagement between the retaining member and a rotary member of the pivot joint of Fig. 2; Fig. 5 is a partly sectional view to illustrate arrangement of a string, a driving wheel, and a slidable tube of the pivot joint of Fig. 2; and Fig. 6 is a sectional view to illustrate an unlocking position of a retaining member in a receiving space of the pivot joint of Fig. 2.

Figs. 1 to 5 illustrate a preferred embodiment of a pivot joint 10 for a stroller frame 1.

The stroller frame 1 includes an upper frame part in the form of a pair of first frame portions 11, and a handle frame part 12 with a pair of second frame portions 122, each of which is coupled to a respective one of the first frame portions 11 via the pivot joint 10. The pivot joint 10 is operable in order to adjust an inclined position of the handle frame part 13 relative to the upper frame part.

The pivot joint 10 includes: a stationary seat member 2 adapted to be connected to the respective first frame portion 11 of the stroller frame 1 and having a first pivot part 22 with a surrounding wall 222 that defines a first cylindrical recess 221 and that has a first annular inner face confining the first cylindrical recess 221 and formed with a plurality of first grooves 223 within the first cylindrical recess 221; a pivot seat member 3 adapted to be

connected to the respective second frame portion 122 of the stroller frame 1 and having a second pivot part 32 with a surrounding wall 322 that defines a second cylindrical recess 323 (see Fig. 3) and that has a second annular inner face confining the second cylindrical recess 323 and formed with a plurality of second grooves 325 within the second cylindrical recess 323, the pivot seat member 3 and the stationary seat member 2 being coaxially coupled to each other such that the first and second cylindrical recesses 221,323 cooperate to form a receiving space; a pivot

pin 65 extending through centers of the first and second cylindrical recesses 221/323 so as to permit the pivot seat member 3 to be turnable relative to the stationary seat member 2 ; a retaining member 63 in the form of a toothed wheel 631 that is disposed in the receiving space around the pivot pin 65 and that is formed with a plurality of teeth 634 and at least a cam recess 636 (see Fig. 4, four cam recess 636 are formed in the retaining member 63 in the preferred embodiment), the retaining member 63 being movable along an axis that is defined by the pivot pin 65 between a locking position (see Fig. 3), in which, the teeth 634 engage

the first and second grooves 223, 325, and an unlocking position (see Fig. 6), in which, the teeth 634 engage the second grooves 325 and disengage the first grooves 223, the retaining member 63 being formed with a first

helical cam face 637 in the cam recess 636, the first helical cam face 637 extending helically and inwardly of the retaining member 63 ; an urging member 62 disposed in the receiving space between the pivot seat member 3 and the retaining member 63 and having one end that is received in a retaining recess 635 of the retaining member 63 for urging the retaining member 63 to move to the locking position; and an actuating unit including a rotary member 64 disposed between the stationary seat member 2 and the retaining member 63 around the pivot pin 65 and having a wheel portion 641 and at least a cam protrusion 642 (see Fig. 4, four cam protrusions 642 are provided on the wheel portion 641 in this preferred embodiment, and respectively correspond to the four cam recesses 636) that projects from the wheel portion 641 into the cam recess 636 and that is formed with a second helical cam face 644 which conforms to and which is in sliding contact with the first helical cam face 637 when the retaining member 63 is at the locking position. The rotary member 64 is turnable about the pivot pin 65 so as to move the second helical cam face 644 toward and away from the first helical cam face 637, which, in turn, moves the retaining member 63 from the locking position to the unlocking position. The actuating unit further includes a string 70 having a fixed end 72 that is connected to the wheel portion 641, and a

pulling end 71 that is exposed from the pivot joint 10 so as to turn the wheel portion 641 about the pivot pin 65, which, in turn, moves the retaining member 63 from the locking position to the unlocking position, when the pulling end 71 is pulled in a direction away from the pivot joint 10.

The rotary member 64 further has a shaft 643 projecting from a center of the wheel portion 641 through the retaining member 63. The actuating unit further includes a driving wheel 61 disposed between the pivot seat member 3 and the retaining member 63 around the pivot pin 65, securely connected to the shaft 643, formed with a string guiding groove 615 and an engaging slot 617, and turnable about the pivot pin 65 for turning the rotary member 64. The fixed end 72 of the string 70 is received in the retaining groove 614 of the driving wheel 61, and is securely connected to the driving wheel 61. The string 70 has a section that extends from the fixed end 72 and that is disposed in the string guiding groove 615. The shaft 643 has an anchored end 647 engaging a periphery of the retaining slot 617 so as to permit synchronous rotation of the rotary member 64 and the driving wheel 61.

The second pivot part 32 of the pivot seat member 3 is formed with a string hole 326. The pivot seat member 3 further has a connecting tube 31 that is

adapted to be connected to the second frame portion 122, and a string guiding tube 33 that extends outwardly from the string hole 326 in a direction parallel to the connecting tube 31. The actuating unit further includes a slidable tube 51 that couples and that is slidably sleeved on one end of the second frame portion 122 and one end of the connecting tube 31. A second string guiding tube 53 is formed on the slidable tube 51 for receiving the pulling end 71 of the string 70.

The string 70 extends outwardly through the string hole 326 and the string guiding tube 33 and into the second string guiding tube 53. The pulling end 71 of the string 70 is fixed to the slidable tube 51 in the second string guiding tube 53 so as to be movable along with the slidable tube 51. A loop-shaped part is formed on the second guiding tube 53, and is operable using one of the fingers of the user so as to facilitate the operation for adjusting the inclined position of the handle frame part 12 relative to the upper frame part.

With the actuating unit, ergonomical adjustment of the inclined position of the handle frame part relative to the upper frame part is possible, and the drawback associated with the prior art can be eliminated.

Claims

CLAIMS: 1. A pivot joint adapted to interconnect first and second frame portions of a stroller frame, said pivot joint comprising: a stationary seat member adapted to be connected to the first frame portion of the stroller frame and having a first pivot part that defines a first cylindrical recess and that has a first annular inner face confining said first cylindrical recess and formed with a plurality of first grooves within said first cylindrical recess ; a pivot seat member adapted to be connected to the second frame portion of the stroller frame and having a second pivot part that defines a second cylindrical recess and that has a second annular inner face confining said second cylindrical recess and formed with a plurality of second grooves within said second cylindrical recess, said pivot seat member and said stationary seat member being coaxially coupled to each other such that said first and second cylindrical recesses cooperate to form a receiving space; a pivot pin extending through centers of said first and second cylindrical recesses so as to permit said pivot seat member to be turnable relative to said stationary seat member ; a retaining member in the form of a toothed wheel

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that is disposed in said receiving space around said pivot pin and that is formed with a plurality of teeth and at least a cam recess, said retaining member being movable along an axis that is defined by said pivot pin between a locking position, in which, said teeth engage said first and second grooves, and an unlocking position, in which, said teeth engage said second grooves and disengage said first grooves, said retaining member being formed with a first helical cam face in said cam recess, said first helical cam face extending helically and inwardly of said retaining member;

an urging member disposed in said receiving space for urging said retaining member to move to said locking position; and an actuating unit including a rotary member disposed between said stationary seat member and said retaining member around said pivot pin and having a wheel portion and at least a cam protrusion that projects from said wheel portion into said cam recess and that is formed with a second helical cam face which conforms to and which is in sliding contact with said first helical cam face when said retaining member is at said locking position, said rotary member being turnable about said pivot pin so as to move said second helical cam face toward and away from said first helical cam face, which, in

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turn, moves said retaining member from said locking position to said unlocking position, and a string having a fixed end that is connected to said wheel portion, and a pulling end that is exposed from said pivot joint so as to turn said wheel portion about said pivot pin, which, in turn, moves said retaining member from said locking position to said unlocking position, when said pulling end is pulled in a direction away from said pivot joint.
2. The pivot joint of Claim 1, wherein said rotary member further has a shaft projecting from a center of said wheel portion through said retaining member, said actuating unit further including a driving wheel disposed between said pivot seat member and said retaining member around said pivot pin, securely connected to said shaft, formed with a string guiding groove, and turnable about said pivot pin for turning said rotary member, said fixed end of said string being securely connected to said driving wheel, said string having a section that extends from said fixed end and that is disposed in said string guiding groove.
3. The pivot joint of Claim 1, wherein said second pivot part of said pivot seat member is formed with a string hole, said pivot seat member further having a connecting tube that is adapted to be connected to the second frame portion of the stroller frame, and a string guiding tube that extends outwardly from said

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string hole, said actuating unit further including a slidable tube that is slidably sleeved on said connecting tube, said string extending outwardly through said string hole and said string guiding tube, said pulling end of said string being fixed to said slidable tube so as to be movable along with said slidable tube.
4. The pivot joint substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.