Persons living in remote locations, such as ranches having a large amount of fenced acreage, experience considerable inconvenience in continually having to stop to open and close gates. This problem is particularly acute in areas where an individual must cross a large number of fenced-in sections in order to reach his destination. Although an automatic gate opening device can solve the inconvenience of opening and closing a large number of gates at remote locations, there are a number of practical and economic difficulties in utilizing such gate openers. In particular, it is very common for the fencing on which the gate is to be installed to have wooden posts which have deteriorated with age. In such cases, it is often necessary to construct a custom-built gate frame to be used in conjunction with the gate opener. Construction of such a frame tends to be very costly and time consuming. Furthermore, once such a frame has been constructed and a gate opener has been installed thereon, the user must bear the additional expense of having commercially available power routed to the gate opener.
A gate opener overcoming the above mentioned difficulty with regard to power is shown in U.S. Pat. No. 4,416,085, which is owned in part by applicant and by this reference incorporated for all purposes. The gate opener shown in said patent is operated by a hydraulic cylinder controlled by a bi-directional gear pump with the cylinder comprising a rod connected to a pivotal linkage which is operable to open and close the gate. A solar power system is provided to maintain a battery in a charged state to provide power for the system.
Various other types of gate or door opening devices have been designed in the past to utilize hydraulic cylinders and a mechanical linkage. A typical device is shown in U.S. Pat. No. 3,936,977 issued to Runft, et al., which has a double acting power cylinder. A pivotal interconnecting linkage is utilized to open a door in response to the movement of a piston within the cylinder.
Other types of gate opening devices have utilized a ram such as that shown in U.S. Pat. No. 3,500,585 to Vollmar. Further examples of gate opening devices are shown in U.S. Pat. No. 3,645,042, issued to Bolli; U.S. Pat. No. 2,592,891 issued to Hall; and U.S. Pat. No. 4,231,190 issued to Tieben.