AUSTRALIA Patents Act 1990 5 COMPLETE SPECIFICATION STANDARD PATENT 10 Application No.: 15 Application Date: 24 July 2014 Priority Date: 20 Applicant: Q-YIELD OUTDOOR GEAR LTD. 25 Address for Correspondence: Schuch IP PO Box 10 615 Wellington 6143 30 New Zealand Complete Specification for the invention entitled: 35 PUSHROD-TYPE TENT FRAME The following statement is a full description of this invention, including the best 40 method of performing it known to us: 1 PUSHROD-TYPE TENT FRAME BACKGROUND OF THE INVENTION 5 1. Field of the Invention The present invention generally relates to tents. More particularly, but not exclusively, the invention relates to a pushrod-type tent frame. 10 2. Description of the Prior Art The increasing popularization of private cars has made self-drive tours an emerging type of tourism. Given this trend, the relevant manufacturers are 15 increasingly competing to develop vehicle accessories for accommodating people who love self-drive tours. In this context, various rooftop tents have been developed among others. A rooftop tent refers to a tent designed to be put up on a car roof and is considered more comfortable than traditional tents that are built directly on the 20 ground and tend to be invaded by the cold, damp air from the ground. The conventional rooftop tents typically have a tent frame composed of multiple interconnected poles that are pivotally connected to each other via joints. To hold the tent at its expanded position, fixing members are deployed around the joints. Thus, when putting up and taking down the conventional rooftop tents, people 25 have to perform operation at each of the joints and fixing members, making the process quite inconvenient and time-consuming. For improving the conventional rooftop tents, semi-automatic and fully-automatic rooftop tents have been introduced, such as the automatic tent frame of China Patent No. 201120240226.0 invented by the same inventor as the 2 present invention. Referring to FIG. 1, the very prior-art tent frame has an intermediate supporting pole 23' that is controllable to slide along its base, and implements a traction rope 31' with a free end thereof connected to the lower end of the intermediate supporting pole 23', so that when a driving device drives a 5 rope windlass 32' to release or roll up the traction rope 31', the tent frame can be expanded or retracted. However, in this known tent frame, the traction rope 31' has a relatively long path, leaving the exposed traction rope 31' highly risky to malfunction. Thus, the existing automatic tent frame still needs to be improved. 10 SUMMARY OF THE INVENTION In view of the need, the present invention, with the aim to remedy the shortcomings of the existing devices, herein provides a pushrod-type tent frame that has simplified structure and improved and enhanced stability as well as 15 reliability. The technical scheme implemented by the present invention is providing a pushrod-type tent frame that comprises a base, a frame linkage and a controlling mechanism; the frame linkage including two support sets arranged at two lateral edges of the base and parallel to each other, each of the two support sets having 20 a supporting pole, an upper supporting pole, and a lower supporting pole that are pivotally connected in sequence, the supporting pole having an outer end pivotally connected to a front edge of the base and the lower supporting pole having an outer end pivotally connected to a rear edge of the base. Therein, the controlling mechanism includes two rod-pushing mechanisms pivotally connected to the two 25 support sets, respectively. Each said rod-pushing mechanism includes a driving device, and has one end pivotally connected to one said lateral edge of the base and an opposite end pivotally connected to the upper supporting pole or the lower supporting pole. Therein, the rod-pushing mechanism comprises a fixed sleeve, a pushing rod 30 received in the fixed sleeve for telescopic movement, and a driving device for driving the pushing rod to move with respect to the fixed sleeve. Therein, the fixed sleeve has a lower end pivotally connected to the base via 3 a holder, and the pushing rod has an upper end pivotally connected to the upper supporting pole or the lower supporting pole via a connecting member. Therein, the fixed sleeve has a lower end pivotally connected to the base via a holder, and the pushing rod has an upper end pivotally connected to a pivot 5 module that pivotally connects the lower supporting pole and the upper supporting pole. Therein, the frame linkage the frame linkage comprises an auxiliary supporting pole that is a U-shaped member with two ends thereof unidirectionally, pivotally connected to the upper supporting poles, respectively. 10 Therein, the frame linkage comprises an auxiliary supporting pole that is a U-shaped member with two ends thereof unidirectionally, pivotally connected to two pivot modules each pivotally connecting the lower supporting pole and the upper supporting pole. With the aforementioned improved scheme, the present invention has the 15 rod-pushing mechanism that has the driving device to be pivotally connected to and control each of the two support sets of the tent frame, so as to expand or retract the tent frame by changing the reach of the telescopic rod assembly, i.e. the controlling mechanism or the rod-pushing mechanisms, so the rooftop tent frame is structurally simpler than the existing devices. Moreover, as compared to 20 the prior-art mechanisms, the telescopic rod assembly of the present invention has its path much shorter and has its structural strength improved, so as to ensure the stability and reliability of the pushrod-type tent frame in terms of performance. 25 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a conventional tent frame expanded; FIG. 2 is a perspective view of a tent frame of the present invention that is taken down; 30 FIG. 3 is a side view of the tent frame of FIG. 2; FIG. 4 is a perspective view of the tent frame of FIG. 2 during its expansion; FIG. 5 is a side view of the tent frame of FIG. 4; 4 FIG. 6 is a perspective view of a tent frame of the present invention that is now fully put up; and FIG. 7 is a side view of the tent frame of FIG. 6. 5 DETAILED DESCRIPTION OF THE INVENTION For further illustrating the means and functions by which the present invention achieves the certain objectives, the following description, in conjunction with the accompanying drawings and preferred embodiments, is set forth as 10 below to illustrate the implement, structure, features and effects of the subject matter of the present invention. The present invention discloses a pushrod-type tent frame. Please refer to FIG. 2 through FIG. 7 for a preferred embodiment of the present invention. As shown in FIG. 2 to FIG. 7, the disclosed tent frame comprises a base 1, a frame 15 linkage 2 and a controlling mechanism. The base 1 is a framework designed to be settled on the round or a car roof. The frame linkage 2 includes two support sets 20 arranged along two lateral edges of the base 1 and parallel to each other. The two support sets 20 are connected by a reinforcing transverse bar 24. Each of the two support sets 20 20 includes a supporting pole 21, an upper supporting pole 22 and a lower supporting pole 23 that are pivotally connected in sequence. The supporting pole 21 has its outer end pivotally connected to a front edge of the base 1, while the lower supporting pole 23 has its outer end pivotally connected to a rear edge of the base 1, so that the base 1, the supporting pole 21 and the upper supporting 25 pole 22, as well as the lower supporting pole 23, jointly form a stable triangle when the tent frame is fully put up. The present invention features the controlling mechanism including two rod-pushing mechanisms 3 pivotally connected to the two support sets 20, respectively. Each of the rod-pushing mechanisms 3 includes a driving device and 30 has one end pivotally connected to one of the lateral edges of the base 1 and an opposite end pivotally connected to the upper supporting pole 22 or the lower supporting pole 23. 5 Each of the rod-pushing mechanisms 3 comprises a fixed sleeve 31, a pushing rod 32 received in the fixed sleeve 31 for telescopic movement, and a driving device 33 for driving the pushing rod 32 to move with respect to the fixed sleeve 31. In the present embodiment, the driving device 33 is deposited at the 5 lower part of the fixed sleeve 31 and is an electric machine. The fixed sleeve 31 has its lower end pivotally connected to the base 1 via a holder 34. The pushing rod 32 has its upper end pivotally connected to the upper supporting pole 22 or the lower supporting pole 23 via a connecting member 35, or is pivotally connected to a pivot module where the lower supporting pole 23 and the upper 10 supporting pole 22 are pivotally connected to each other. The frame linkage 2 further comprises an auxiliary supporting pole 25. The auxiliary supporting pole 25 is a U-shaped member having two ends that are unidirectionally, pivotally connected to the upper supporting poles 22, respectively, or pivotally connected to the pivot module where the lower supporting pole 23 and 15 the upper supporting pole 22 are pivotally connected to each other, so as to fully expand the tent frame and thereby the tent roof. The unidirectional, pivotal connection refers to that the auxiliary supporting pole 25 is restricted to rotate against the upper supporting pole 22 for a preset angular range. In the present embodiment, the preset angular range is almost 90 degrees. It is to be noted that 20 if the angular range were set too large, the tent frame would be unable to fully put up the tent roof. Referring to FIG. 2 and FIG. 3, the disclosed tent frame, when retracted or taken down, has all the poles staying close with the base 1, and the pushing rod 32 of the rod-pushing mechanism 3 is withdrawn into the fixed sleeve 31. By 25 activating the driving device 33, the pushing rod 32 is driven to extent outward from the fixed sleeve 31. With the extension of the rod-pushing mechanism 3, as shown in FIG. 4 and FIG. 5, the lower supporting pole 23 and the upper supporting pole 22 are pushed to rotate upward and simultaneously draw the supporting pole 21 to rotate upward until the pushing rod 32 achieves its rated reach, where the 30 supporting poles of the tent frame are fully expanded, as shown in FIG. 6 and FIG. 7. To take down the tent, the driving device 33 is operated to move reversely, meaning that it withdraws the pushing rod 32 back to the fixed sleeve 31. At this time, the pushing rod 32 no more props up the lower supporting pole 23 or the 6 upper supporting pole 22, so that pole falls down under the gravity. When all the supporting poles come down, the tent is taken down. To sum up, the present invention has the rod-pushing mechanism 3 that has the driving device 33 to be pivotally connected to and control each of the two 5 support sets 20 of the tent frame, so as to expand or retract the tent frame by changing the reach of the telescopic rod assembly, i.e. the controlling mechanism or the rod-pushing mechanisms, so the rooftop tent frame is structurally simpler than the existing devices. Moreover, as compared to the prior-art mechanisms, the telescopic rod assembly of the present invention has its path much shorter 10 and has its structural strength improved, so as to ensure the stability and reliability of the pushrod-type tent frame in terms of performance. The present invention has been described with reference to the preferred embodiments and it is understood that the embodiments are not intended to limit the scope of the present invention. Moreover, as the contents disclosed herein 15 should be readily understood and can be implemented by a person skilled in the art, all equivalent changes or modifications which do not depart from the concept of the present invention should be encompassed by the appended claims. 7