Rod puller
An apparatus, system and method are described for removing rods from wood mats, the apparatus configured to assume an open position and a closed position. The apparatus has machine body, an attachment at the rear end of the machine body configured to attach a hydraulic cylinder, a rod that is slidably positioned within the machine body a spring within the machine body, the spring compressable by the rod, levers rotatably attached to the body, each lever having an extension arranged to penetrate a hole on the machine body and to fit within a rod depression on the rod therethrough, jaws protruding from the machine body, each jaw having a curved shape and a pointed end, each jaw rotatably movable; and a jaw ring positioned within the machine body contacts the jaws, wherein the apparatus assumes the closed position to bring the pointed ends of the jaws together radially.
1. An apparatus for removing rods from wood mats, the apparatus configured to assume an open position and a closed position, the apparatus comprising:
a generally cylindrical machine body, having a lateral side, a front end, a rear end, and a longitudinal axis between the front end and the rear end;
an attachment at the rear end of the machine body configured to attach a hydraulic cylinder to the machine body;
a rod that is slidably positioned within the machine body, the rod having a rod depression at a front end of the rod and connected to a rod extender at the front end of the rod;
a spring within the machine body, the spring configured to be compressed by the rod;
one or more levers rotatably attached to the lateral side of the machine body, each lever having a locking lever extension arranged to penetrate a hole on the lateral side of the machine body and to fit within the rod depression on the rod therethrough;
a plurality of jaws protruding from a front end of the machine body, each jaw of the plurality of jaws having a curved shape and a pointed end, each jaw rotatably mounted to a jaw mount affixed to the rod extender and movable with respect to the axis; and
a jaw ring positioned within the front end of the machine body and configured to slidably contact the jaws,
wherein when the spring is compressed and the levers are deactivated, the apparatus assumes the closed position whereby the machine body slides with respect to the rod to compress the spring and to align the rod depression with the locking lever extensions, and retracts the plurality of jaws to slide and pivot around the jaw ring to bring the pointed ends of the jaws together radially.
2. The apparatus of claim 1 , wherein the levers are activated to place the apparatus in the open position by removing the locking lever extensions from the rod depression, releasing the spring to decompress and slide the rod and the rod extension towards the front of the machine body, thereby allowing the jaws to spread apart from each other in a radial direction.
3. The apparatus of claim 1 , wherein the apparatus is configured to be mounted onto a table that can displace the apparatus along three degrees of freedom.
4. The apparatus of claim 1 , wherein the apparatus is made of metal.
5. The apparatus of claim 1 , wherein the jaw mount has a central hub affixed to the rod extension, and each of the plurality of jaws is rotatably affixed to the jaw mount such that the pointed ends of the jaws are directed radially inward and the pointed ends of the jaws can rotate to move towards and away from the axis.
6. The apparatus of claim 1 , wherein the rod extender comprises a rod head support at a front end of the rod extender, the rod extender configured to extend beyond the front end of the machine body when the apparatus is in the open position.
7. The apparatus of claim 6 , wherein the rod head support has a generally circular depression on a front face thereof.
8. The apparatus of claim 1 , wherein the jaw ring is annular and attached to the machine body so as to be concentric within the machine body and flush with the front end of the machine body, the jaw ring having a variable thickness.
9. The apparatus of claim 8 , wherein the jaw ring has first thickness at the front end that increases in a gradual manner to a maximum thickness near the rear of the jaw ring, and then decreases.
10. The apparatus of claim 8 , wherein the jaw ring has a cross sectional profile that is first flat, then has a slope that increases to a maximum height, and then decreases in a curved manner.
11. The apparatus of claim 8 , wherein the variable thickness of the jaw ring includes a curved rear portion that rests against a rear portion of the jaws when the apparatus is in the open position, and a front portion that rests against a middle portion of the jaws when the apparatus is in the closed position, and the variable thickness causes the jaws to rotate as the apparatus moves between the open and closed positions.
12. The apparatus of claim 1 , wherein the pointed end of the jaws are knives that are configured to embed into wood of the wood mats.
13. A system for removing rods from wood mats, the system comprising:
the apparatus of claim 1 ;
a hydraulic cylinder attached to the apparatus;
a support table that supports the apparatus and is configured to displace the apparatus along three degrees of freedom; and
an enclosing housing attached to the support table, the housing sized such that when the apparatus is retracted into the housing, the levers on the apparatus contact the housing and are activated to place the apparatus into the open position.
14. The system of claim 13 , wherein the apparatus is arranged to be moved by the support table into and out of the enclosing housing in a direction of the axis.
15. A method of removing metal rods from a wooden mat, the method comprising:
positioning the apparatus of claim 1 near a head of the metal rod;
aligning the head of the metal rod with a rod head support at a front end of the rod extender, the rod extender configured to extend beyond the front end of the machine body when the apparatus is in the open position;
deactivating the levers and compressing the spring to place the apparatus is the closed position wherein the jaws partially embed into the wooden mat and surround the head of the metal rod;
retracting the apparatus along its axis, thereby removing the metal rod from the wooden mat; and
activating the levers to eject the rod from the apparatus.