Convertible tandem stroller frame

1. A convertible tandem stroller frame is featured in being capable of locking in a tandem stroller mode for installing a second seat and concurrently transporting two occupants and capable of converting said mode into a single seat mode for transporting one occupant by manipulating a release actuator installed at a front portion thereof; said convertible tandem stroller frame including:

a front rack, having at least a front strut equipped with a front wheel of the convertible tandem stroller frame;

a rear rack, having a pair of rear side struts each being equipped with a rear wheels of the convertible tandem stroller frame, and a pair of push bars connected to the rear side struts for pushing the convertible tandem stroller frame from rear side;

at least a longitudinal telescopic mechanism being extendable and retractable for lockably and adjustably connecting the front rack and the rear rack, and;

at least a locking mechanism associated with the release actuator, and adopted to lock and un-lock the longitudinal telescopic mechanism by manipulating the release actuator at the front portion of the convertible tandem stroller frame;

wherein the front rack further includes a first seat for accommodating an occupant to sit thereon; and

wherein the release actuator includes a handle operatively mounted under the first seat, and associates the locking mechanism by at least a flexible connecting element.

2. The convertible tandem stroller frame of claim 1 , wherein the first seat is mounted on the second inner tubes.

3. A convertible tandem stroller frame is featured in being capable of locking in a tandem stroller mode for installing a second seat and concurrently transporting two occupants and capable of converting said mode into a single seat mode for transporting one occupant by manipulating a release actuator installed at a front portion thereof; said convertible tandem stroller frame including:

a front rack, having at least a front strut equipped with a front wheel of the convertible tandem stroller frame;

a rear rack, having a pair of rear side struts each being equipped with a rear wheels of the convertible tandem stroller frame, and a pair of push bars connected to the rear side struts for pushing the convertible tandem stroller frame from rear side;

at least a longitudinal telescopic mechanism being extendable and retractable for lockably and adjustably connecting the front rack and the rear rack, and;

at least a locking mechanism associated with the release actuator, and adopted to lock and un-lock the longitudinal telescopic mechanism by manipulating the release actuator at the front portion of the convertible tandem stroller frame;

wherein the longitudinal telescopic mechanism includes:

a pair of first inner tubes, connected to the front rack;

a pair of second inner tubes, spaced apart from the first inner tubes and connected to the front rack;

a pair of first outer tubes, connected to the rear rack and telescopically engaged with the first inner tubes; and

a pair of second outer tubes, spaced apart from the first outer tubes and telescopically engaged with the second inner tubes;

wherein the locking mechanism includes a pair of first spring-biased latches retractably mounted inside the first inner tubes and capable of protruding outwardly from the first inner tubes to engage the first outer tubes thereby positioning the first outer tubes relative to the first inner tubes in step-less increments and at least a predetermined position; and

wherein the front rack further includes a first seat mounted on the second inner tubes for accommodating an occupant to sit thereon, and wherein the release actuator is a handle operatively mounted under the first seat, and associates the pair of first spring-biased latches by a first flexible connecting element.

4. The convertible tandem stroller frame of claim 3 , wherein the pair of first inner tubes are pivoted with the front strut, and the first outer tubes are pivoted with the rear side struts that permits the convertible tandem stroller frame to be foldable into a compact configuration for storage and shipping.

5. The convertible tandem stroller frame of claim 3 , wherein the first outer tubes are pivoted with the rear side struts and the push bars for permitting the rear rack to be foldable into a compact configuration.

6. The convertible tandem stroller frame of claim 3 , wherein the rear rack further includes a pair of linking rods adapted for pivotally linking the push bars to the rear side struts, wherein the push bars each has a distal end for lockably abutting on an intermediate portion of the rear side struts for locking the rear rack in an erected use configuration, and unlocking the rear rack from the erected use configuration.

7. The convertible tandem stroller frame of claim 3 , further includes a first lock element operatively mounted on the first outer tubes for releasably engaging with the first inner tubes to position the first inner tubes relative to the first outer tubes.

8. A convertible tandem stroller frame is featured in being capable of locking in a tandem stroller mode for installing a second seat and concurrently transporting two occupants and capable of converting said mode into a single seat mode for transporting one occupant by manipulating a release actuator installed at a front portion thereof; said convertible tandem stroller frame including:

a front rack, having at least a front strut equipped with a front wheel of the convertible tandem stroller frame;

a rear rack, having a pair of rear side struts each being equipped with a rear wheels of the convertible tandem stroller frame, and a pair of push bars connected to the rear side struts for pushing the convertible tandem stroller frame from rear side;

at least a longitudinal telescopic mechanism being extendable and retractable for lockably and adjustably connecting the front rack and the rear rack, and;

at least a locking mechanism associated with the release actuator, and adopted to lock and un-lock the longitudinal telescopic mechanism by manipulating the release actuator at the front portion of the convertible tandem stroller frame;

wherein the longitudinal telescopic mechanism includes:

a pair of first inner tubes, connected to the front rack;

a pair of second inner tubes, spaced apart from the first inner tubes and connected to the front rack;

a pair of first outer tubes, connected to the rear rack and telescopically engaged with the first inner tubes; and

a pair of second outer tubes, spaced apart from the first outer tubes and telescopically engaged with the second inner tubes;

wherein the locking mechanism includes a pair of second spring-biased latches retractably mounted inside the second inner tubes and capable of protruding outwardly from the second inner tubes to engage the second outer tubes thereby positioning the second outer tubes relative to the second inner tubes in step-less increments and at least a predetermined position; and

wherein the front rack further includes a first seat mounted on the second inner tubes for accommodating an occupant to sit thereon, and wherein the release actuator is a handle operatively mounted under the first seat, and associates the pair of second spring-biased latches by a second flexible connecting element.

9. The convertible tandem stroller frame of claim 8 , further includes a second lock element operatively mounted on the second outer tubes for releasably engaging with the second inner tubes to position the second inner tubes relative to the second outer tubes.