Pin locking device and method of locking

A locking device for locking one or more objects together includes a lock stud defined by an elongated shaft having a head at a first end and an annular recess at a second end, and a lock body that slides over and locks onto the second end. The lock body includes an outer housing having an aperture for receiving the second end of the elongated shaft. A cylinder lock mechanism is positioned in the outer housing, and the cylinder lock is rotatable between a locked and an unlocked position. The cylinder lock is rotationally coupled to a locking disc that is eccentrically disposed in the outer housing with respect to the aperture of the outer housing. The locking disc has an aperture therein that engages the annular recess in the elongated shaft when the cylinder lock is rotated to the locked position. The locking device also includes a sleeve that is dimensioned to slide over the elongated shaft to allow the locking device to be used for locking through several different sized apertures.

FIELD OF THE INVENTION

This invention relates generally to locking devices. In particular, the present invention relates to a pin locking device that may be used to lock utility hitches for connecting vehicles, or to lock one object to another object such as a spare tire to a motor vehicle.

BACKGROUND OF THE INVENTION

Various types of locking devices have been designed for a multitude of purposes. In the field of utility hitches, U.S. Pat. No. 3,605,457 to Foster and U.S. Pat. No. 3,139,291 to Geresy disclose trailer hitch locking devices that are used to lock a trailer hitch tongue to the ball of a conventional type trailer hitch.

Another type of device, called a pin lock or a coupler lock is generally used for locking together the central hitch member and outer hitch member of telescoping type utility hitches. In this type of utility hitch, the central hitch member fits telescopically into an outer hitch member. Apertures through both hitch members are aligned so that the pin lock can be inserted through the apertures to hold the central hitch member within the outer hitch member. The pin lock is locked onto these members to prevent removal of the pin, so that the vehicle that is connected to the hitch member, such as a trailer, cannot be stolen.

U.S. Pat. No. 5,540,065 to Wyers is an example of such a prior art pin locking device. The disclosed pin locking device includes a rod having a stop at one end and a key-like male portion at its forward tip. A barrel-type combination lock forms an enlarged head and locks over the rod's forward shackle.

U.S. Pat. No. 4,711,106 to Johnson is another example of a prior art pin locking device. The disclosed device includes a stud having a threaded axial hole extending rearwardly from the forward end thereof and a keyed portion. A knob locks over a forward position of the stud and includes a casing with an inner surface that has a keyway. The keyway receives the corresponding key on the stud to prevent rotation of the casing with respect to the stud. The knob also includes a tumbler housing that is mounted in an axially fixed position within the casing to rotate freely when a key is inserted into the tumbler housing, and to remain locked in a fixed position when the key is withdrawn.

Similarly, U.S. Pat. No. 5,284,038 to Johnson discloses a pin locking device that includes a threaded stud with a flat face cut through the threaded surface. The flat face is parallel to the axial direction of the stud. The device also includes a knob that locks over a forward section of the stud and includes a casing having an inner surface that defines a hole extending axially through the casing. The inner surface of the casing has a flat surface extending axially that receives the corresponding flat face on the threaded stud to prevent rotation of the casing with respect to the stud. The knob also includes a tumbler housing that is mounted in an axially-fixed position within the casing to rotate freely when a key is inserted into the tumbler housing, and to remain locked in a fixed position when the key is withdrawn. Fitted into the rearward end of the tumbler housing is a sleeve having a threaded axial hole that engages the threaded stud when the tumbler housing is turned by a key to thereby pull the forward section of the stud into the casing hole.

U.S. Pat. No. 5,197,314 to Stillwagon et al. describes a prior art locking mechanism for a door latch. The mechanism comprises a post and collar gripping and release mechanism cooperatively mounted to the door and the door frame of a vending machine, cabinet, or the like. The mechanism provides an initial latching function in the form of a frictional gripping of the post by the collar. The locking mechanism further comprises a lock assembly associated with the post and collar mechanism to provide a primary locking function and to effect release of the latching function.

SUMMARY OF THE INVENTION

The present invention is directed to a pin lock. The pin lock has a first locking member with a locking end and a second locking member with a first aperture for receiving the locking end. The second locking member includes a locking mechanism positioned inside the outer housing, at least a portion of which is rotatable between a locked position and an unlocked position, and a locking part rotationally coupled with the locking mechanism. The locking part has an axis of rotation which is eccentrically disposed with respect to the longitudinal axis of the first aperture, and the locking part is dimensioned to engage the locking end of the first locking member.

The locking part has a second aperture that is dimensioned to allow passage of the locking end therethrough when the locking mechanism is in the unlocked position. The locking part is further dimensioned to engage the locking end of the first locking member when the locking mechanism is in the locked position.

In one embodiment, the locking part is substantially disc shaped and the second aperture is a substantially wedge-shaped cutout. A portion of the cutout is dimensioned to engage the locking end of the first locking member.

In another embodiment, the locking part is a substantially disc shaped plate having a first through hole and a second through hole overlapping one another. The first through hole is dimensioned to engage a portion of the locking end of the first locking member.

According to one aspect of the present invention, the locking mechanism includes a cylinder shell permanently fixed in the outer housing and a cylinder plug rotatably mounted in the cylinder shell. The locking part is rotationally coupled to the cylinder plug by an extension plate that is keyed to a tail portion of the cylinder plug.

According to another aspect of the present invention, the first locking member has a shaft portion with a knob disposed at the locking end. The first locking member also includes a retaining end including an enlarged portion. Optionally, the lock includes a sleeve dimensioned to slide over a portion of the first locking member.

The present invention is also directed to a method of locking the end of a shaft to a locking mechanism. The method includes providing a shaft with a locking section and providing a locking mechanism dimensioned to receive the locking section of the shaft. The locking mechanism has a first aperture with an axis of rotation and a second aperture with an axis of rotation wherein the axis of the first aperture is eccentrically disposed with respect to the axis of the second aperture. The method further includes rotating the first aperture into alignment with the second aperture, inserting the end of the shaft through the first and second apertures, and rotating the second aperture out of alignment with the first aperture to engage the locking section of the shaft.

According to one aspect of the method, the first aperture is rotated in and out of alignment with the second aperture by inserting a key into the cylinder plug and turning the key.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1is a top view of a pin lock10according to the present invention, shown in a locked configuration.FIG. 2is an isometric view of pin lock10in an unlocked configuration.FIG. 3is an exploded view of the pin lock10of FIG.1. Referring toFIGS. 1 and 2, pin lock10includes two lock members, a lock stud15and a lock body20. Lock body20slides over an elongated shaft25of stud15and can be locked thereon by a lock mechanism that is shown in detail in FIG.3. Optionally, pin lock10includes a sleeve26that is dimensioned to slide over elongated shaft25, thus allowing the pin lock10to be used for locking together parts that have apertures of various sizes. Sleeve26can include a retaining ring27disposed within its inner diameter to hold sleeve26on elongated shaft25. Retaining ring can be formed of plastic, rubber or other suitable materials and can extend either partially or entirely along the length of sleeve26.

Referring toFIG. 3, lock stud15includes an enlarged head28that is permanently attached to an elongated shaft25by welding or other means of attachment known in the art, such as pinning. Alternatively, other retaining members may be used, such as a bend or deformation in the elongated shaft25sufficient to prevent it from passing through a hole of slightly larger diameter than shaft25. In another embodiment, shaft25and elongated head28can be a single piece machined from metal or other suitable materials known in the art.

Elongated shaft25has a knob30at its opposite end, the knob30being formed by an annular recess35proximate the end of the shaft25. Alternatively, shaft25may have a section of increased diameter at its end (not shown), such as a knob or other appendage. In one embodiment, elongated shaft25is constructed of about ½ inch diameter solid steel, but other materials such as titanium or aluminum may be suitable as well. Also, elongated shaft25can be made in many different lengths and diameters that are suitable for different applications.

Still referring toFIG. 3, lock body20includes a hollow outer housing40that has an aperture45therein (shown inFIG. 4) that is dimensioned to receive the locking end of elongated shaft25, having knob30thereon. A cylinder shell50is positioned in the outer housing40. In a preferred embodiment, cylinder shell50is permanently fixed inside outer housing40by retaining pins55, which extend out of holes60in the cylinder shell50and through holes65in the outer housing40. Other methods of attachment, such as welding or bonding, may also be used to fix cylinder shell50into the outer housing40, the method of attachment not being critical to the invention.

An interior cavity70extends axially through cylinder shell50. The interior cavity70is preferably located eccentrically with respect to the longitudinal axis of the cylinder shell50. Interior cavity70is generally cylindrical and has a pair of passageways75therein. Passageways75are positioned on opposite sides of the diameter of interior cavity70.

A key-operated cylinder plug85, of the type well known in the art, is turnable in interior cavity70. Cylinder plug85has a keyhole87and a key slot (not shown) for receiving a key. Several radially extending tumblers90(shown inFIG. 4) extend into the key slot at one end, and into passageways75in the interior cavity70at the other end. When no key is inserted into the key receiving slot, the extended tumblers90prevent rotation of the cylinder plug85in the interior cavity70. However, when a matching key is inserted into the slot, the tumblers90retract into the cylinder plug85, thus allowing the cylinder plug85to rotate in the interior cavity70. Suitable alternatives well known in the art, such as wafers or pins, may be used instead of tumblers90.

A locking part100, also referred to as locking disc100, is coupled to the cylinder plug85by extension plate105. Locking disc100is constructed of metal. In one embodiment, locking disc100is constructed of two identical pieces of metal that are fastened together, however any number of constructions may be suitable for the locking disc100. In a preferred embodiment, the locking disc100is two identical pieces of stamped steel plate.

Extension plate105is preferably a stamped part that is keyed to fit on the plug tail110(shown inFIG. 4) of the cylinder plug85. The extension plate105and the locking disc100are held together by two posts115, which are swaged holding the locking disc100and the extension plate105together in spatial relation. Alternatively, the parts may be held together by other means well known in the art, such as welding or bonding. In another embodiment, locking disc100, extension plate105and posts115are a single piece formed by casting, stamping or other methods known in the art. Extension plate105rigidly couples cylinder plug85and locking disc100, so that the two parts are rotationally coupled.

As shown inFIG. 4, a rubber O-ring seal120sits in a cylindrical pocket125in the aperture45in the outer housing40, and a cap130snaps over the end of the outer housing40. The O-ring seal120and the cap130work in conjunction to seal the outer housing40from dirt and water.

Referring toFIGS. 5A and 5B, the locking disc100of one embodiment of the invention is shown in detail. The disc100has a locking aperture140therein, preferably in the shape of a “V”. The aperture140has an engaging portion145that is dimensioned to lock into a portion of the annular recess35in shaft25. The non-engaging portion147of the aperture140is wider than the engaging portion145and is dimensioned to allow the shaft25to pass through the non-engaging portion147without contact. The axis of rotation of the disc100and the center of aperture45in the outer housing40are eccentrically aligned. This eccentric alignment causes the locking aperture140in the disc100to rotate between the locked position (FIG. 5B) and the unlocked position (FIG. 5A) when the key (not shown) is turned 90° in the cylinder plug85. When in the locked position (FIG.5B), engaging portion145of the locking aperture140enters annular recess35in shaft25and engages knob30. When in the unlocked position (FIG.5A), engaging portion145is displaced from shaft25and allows shaft25to pass freely through non-engaging portion147. Thus, the relationship between aperture45in the outer housing40and locking disc100provides the locking/unlocking function of the pin lock10.

FIGS. 6A and 6Bshow an alternate embodiment of a locking disc150. In this embodiment, locking disc150has two eccentric holes155,160cut through it. Non-engaging hole155is dimensioned to allow shaft25to freely pass there through, while engaging hole160is dimensioned to lock into annular recess35in shaft25. The two eccentric holes155,160overlap to form a locking aperture165in locking disc150. Similar to the embodiment discussed above, disc150has a rotational axis A—A that is eccentric with respect to the longitudinal axis X—X of aperture45in the outer housing40, as shown in FIG.4. Longitudinal axis X—X of aperture45corresponds to the longitudinal axis of pin lock10. Thus, a 90° rotation of the cylinder plug85, by way of a matching key, rotates the disc150between the locked position (FIG. 6B) and the unlocked position (FIG.6A). When in the locked position (FIG.6B), engaging hole160enters annular recess35in shaft25and engages knob30. When in the unlocked position (FIG.6A), engaging hole160is displaced from shaft25and allows shaft25to pass freely through non-engaging hole155. Many other configurations for the locking disc may also be acceptable, such as a disc with a circular, rectangular or bean-shaped aperture, among other shapes. Also, the disc and aperture may be modified to provide a variety of angles of rotation between the locked and unlocked positions, such as 60° or 120°, for example.

To use the pin lock10to lock items together, a user must first insert a matching key into the cylinder plug85by way of the keyhole87and turn the key 90° to the open position. Turning the key to the open position rotates the cylinder plug90and ultimately the locking disc100so that the non-engaging portion147of the locking aperture140is aligned with the aperture45in the outer housing40.

Next, the user inserts the locking end of shaft25with the knob30through openings in the items to be locked, such as through the hole of a receiver and trailer hitch ball assembly, and then into the aperture45in outer housing40.

Finally, the user turns the key 90° back to the locked position and removes the key. This rotates the engaging portion145of the locking aperture165into alignment with the aperture45in the outer housing40, and thereby engages the engaging portion145with the annular recess35in shaft25. The knob30prevents the shaft25from being removed from the lock body20.

To unlock the pin lock, the user inserts the key into the cylinder plug85and turns it 90° to the open position. This rotates the engaging portion145of the locking aperture140out of engagement with the annular recess35and allows the shaft25to be freely removed from the aperture45in the outer housing40. In this manner, the stud15is completely separated from the lock body20, and the items that were locked together can now be separated from one another.

It should be understood that variations and modifications within the spirit and scope of the invention may occur to those skilled in the art to which the invention pertains. Accordingly, all expedient modifications readily attainable by one versed in the art from the disclosure set forth herein that are within the scope and spirit of the present invention are to be included as further embodiments of the present invention. Accordingly, the scope of the present invention is to be defined as set forth in the appended claims.