US 3367613 A
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| N. CHRISTENSEN 3,367,613
GRAVITY RETURN MECHANISM FOR MAIL BOXES, GATES OR THE LIKE Filed Jline 15, 1966 2 Sheets-Sheet l 1/ Ill/Ill g /Illa L/IPS M (HR/STENfE/V INVENTOR.
#15 ATT'Y Feb. 6, 1968 L. N. CHRISTENSEN GRAVITY RETURN MECHANISM FOR MAIL BOXES, GATES OR THE LIKE Filed June 15, v1966 FIG. 5
2 Sheets-Sheet 2 FlC1.4-
BY c4. 6 at: ms A rrr 3,367,613 GRAVITY RETURN MECHANISM FOR MAIL BOXES, GATES OR THE LIKE Lars N. Christensen, Viborg, S. Dak. 57070 Filed June 15, 1966, Ser. No. 557,695 3 Claims. (Cl. 248-145) ABSTRACT OF THE DISCLOSURE A gravity return mechanism for a mail box or gate or United States Patent Ofiice the like in which a cover is provided over the mechanism to protect it and in which the movable cover co-acts with pin means on the stationary part of the mechanism to limit the amount of movement allowed.
This invention pertains to mountings for rural mail boxes and more particularly to a mounting which will allow a displacement of the box if it should be struck, and will automatically return the box to its initial position when the striking force is withdrawn. The mechanism may also be useful for a swinging gate.
Rural mail boxes are normally mounted on a post adjacent to a road. The box must extend to a point where it can be easily reached by a mail carrier from the window of his automobile. In this position the box is in a very vulnerable spot. Trucks in particular, when driving along the road are apt to hit the box with an edge of the truck box and severely damage or destroy the box.
By my invention I provide a mounting for such a box which will permit the box to be displaced rather easily so that the blow will not cause such severe damage. After the force is removed the box will automatically swing back into its original position and be ready for use. The mechanism uses a cam and follower operated by gravity to accomplish this result.
The mechanism by which the result is accomplished may also be used for a swinging gate. In such usage it provides a completely enclosed gate return device so that the gate may be opened and will return to its original position by a mechanism completely covered to protect it from the elements.
A more complete understanding of my invention in its embodiments may be had from a study of the following specification and the figures in which:
FIG. 1 is an exploded view of the device of my invention showing the individual parts in an expanded relationp,
FIG. 2 is a longitudinal sectional view of the device assembled, but without the mail box,
FIG. 3 is an elevational view of the mail box fully mounted in the device,
FIG. 4 is a sectional view of the device of FIG. 3, and
FIG. 5 is an elevational view of an alternative embodiment of my invention as adapted for mounting a gate.
Briefly my invention comprises a gravity-type return device adapted to return a horizontally rotatively displaced device to its original position. This is accomplished by the use of a cam and a roller type follower. The cam is shaped to force the follower to rise on the cam as the follower is rotatively displaced, such rotation being in a horizontal direction. The device is fully enclosed so as to avoid problems of dust and corrosion and the like.
More specifically and referring to the drawings my device is adapted to be mounted on a tubular post 10. A cam block 11 is mounted on the post by providing a portion 12 of reduced diameter adapted to fit within the post. The cam surface 13 is formed on a head 14 of diameter approximately equal to that of the post.
The cam surface 13 is shaped to provide diametrically 3,367,613 Patented Feb. 6, 1968 opposed valleys and rises of a shape to accommodate a cylindrical follower. The follower is composed of a pair of rollers 15, which may be ball or roller bearings or the like, disposed on a shaft 16. The shaft 16 is fastened within a cap 17 which is adapted to fitsmoothly over the post 10 and the head 14 as shown in FIG. 2. The fastening may easily be acomplished by tapping threads into each end of the shaft 16 and using cap screws 18 or the like extending through the cap 17 and into the threaded axle.
It will now be apparent that when the cap 17 carrying the axle 16 and rollers 15 is in the position shown in FIG. 2, it is at its lowest position. As it is turned from that position through an angle of ,-it will be raised because of the rise in the cam surface 13 which forces the rollers to ride upward. The weight of the device results in a normal tendency for the whole upper assembly to return to its original position. Thus, if the force tending to turn the cap 17 is released, the weight will cause the follower rollers 15 to recede to the valley of the cam and the cap 17 will return to its original position.
This motion can be very useful in the mounting of rural mail boxes as shown in FIGS. 3 and 4. The assembly here is essentially that of FIG. 2. In order to prevent rotation of more than 90, an opening 20 is cut into the cap along its side. This opening covers an arc of approxirnately (that is, 90 on each side of the at rest position) and extends axially of the cap for a distance just slightly greater than the maximum rise of the cam. A pin 21 is inserted through this opening and is removably fixed to either the post 10 or the block 11. The pin is positioned so that it touches the upper surface of the opening 20 at about the center of the arc of the opening when the cap is in the at rest position. Thus, movement of the cap is restricted to approximately 90 in a longitudinal turning direction and to about the maximum rise of the cam in a vertical direction.
A mail box 23 is mounted on the cap 17 by means of brackets 24 of some convenient type. The box is preferably extended away from the post at a reasonable distance so that the adjacent roadway is left clear of surface obstruction. This places the box near the traveled portion of the road where it is readily reached by the mail carrier. However, the box is also readily struck by truck boxes or the like which use the road. With my device, if the box is so struck, it merely swings away and is returned to its original position by gravity with a mininiilm of damage. The motion is limited to a 90 turn by the pin 21 extending through the opening 20. This limitation assures that the box will again return to its proper position without turning to face the opposite direction.
It will be noted that my device is completely covered by the cap 17 which also forms a part of the mounting for the mail box. Thus the working parts are completely shielded from rain or dust and the like. This assures longer useful life for my device than if it were open and also provides a convenient mounting means for mounting the mail box brackets 22.
Another use of my invention might be in a swinging gate. As shown in FIG. 5, I can provide a partial post 25 fixed to a permanent post 26 by brackets 27. The post 25 is similar in function and form to the post 10. This dual post arrangement is necessary, since the fixed part of the fence cannot be fastened to the post 25 without interfering with the operation of the cap 28.
This cap 28 is similar to the cap 17 of the previously described device except that it is considerably longer to cover most of the post 25. It has a similar opening 29 found in it and in other respects performs the function of the cap 17 such as carrying the cam follower device. A gate 29 is fixed to the cap 28 and swings with it.
The operation of this gate is similar to that of the mail box. As it is displaced rotatively, it is carried upward by the cap 28 which is forced upward by the follower riding up on the rising cam surface. Motion is limited by the engagement of the extending part of the upper bracket 27 with the surfaces of the opening 29, and thus the gate always returns to its original position. Again it should be noted that my device is fully enclosed and therefore protected.
Having thus described my invention in its embodiment I am aware that further and extensive variations may be made therefrom without departing from the spirit and scope of my invention as limited only by the following claims.
1. A device of the class described comprising a post, cam means on said post, follower means engaging said cam means, said cam means providing valleys and rises, cap means fixed to said follower means to raise said cap means as said follower means follows said rises and to lower said cap means as said follower means returns to said valleys, said cap means covering said cam means and said follower means and closely embracing said post, said cap means being formed to provide an opening therein,
4 pin means affixed to said post and extending through said opening, said opening being of such size and shape to allow movement of said cap means through an arc of about 180 and an axial distance of about the amount of rise in said cam means.
2. The device of claim 1 in which bracket means are fixed to said cap means, and a mail box is mounted on said brackets.
3. The device of claim 1 in which said post is fixed to a permanent post by bracket means, said pin means being a part of one of said bracket means and said cap means being elongated to cover nearly all of said first named post and gate means fixed to said cap means.
References Cited UNITED STATES PATENTS ROY D. FRAZIER, Primary Examiner.
FRANK DOMOTOR, Assistant Examiner.