to external components and have thru holes which allow their respective piston rods to emerge from the hydraulic cylinder the end caps are also interchangeable so that the top end cap and the bottom end cap can be switched the hydraulic actuator apparatus is symmetric and can be rotated with respect to its connection to external components application_number US 201313934498 A description before explaining at least one embodiment of the invention in detail it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings the figures and written description are provided to teach any person skilled in the art to make and use the inventions for which patent protection is sought the invention is capable of other embodiments and of being practiced and carried out in various ways those skilled in the art will appreciate that not all features of a commercial embodiment are shown for the sake of clarity and understanding persons of skill in the art will also appreciate that the development of an actual commercial embodiment incorporating aspects of the present inventions will require numerous implementation u2014 specific decisions to achieve the developer 39 s ultimate goal for the commercial embodiment while these efforts can be complex.