Description:
This invention relates in general to antennas for the reception or transmission of electromagnetic waves and more particularly pertains to an insulative antenna base that can be mounted upon land vehicles and boats to support the antenna. The base support is constructed to hold the antenna upright and is arranged to permit the antenna to be pivoted into the horizontal position for storage or when a reduction in height is desired. The base support allows the antenna to be rotated and provides detented stations at 90 positions.
BACKGROUND OF THE INVENTION
Where an antenna is employed upon a boat, it is often required to have the antenna upright for long periods of time while the boat is in open water. Inasmuch as some antennas may be directionally sensitive, it is advantageous to mount the antenna so that it can be rotated when desired. When the boat enters a harbor or waterway where it must pass under obstructions such as bridges, it is necessary to have the antenna mounted so that it can be quickly pivoted into the horizontal and locked in that position. A suitable antenna mount, therefore permits the antenna to be locked in the upright position and also allows the antenna to be locked in the horizontal position.
OBJECT OF THE INVENTION
The principal objective of the invention is to provide an efficient and inexpensive insulative mount for attaching an antenna firmly and solidly to a vehicle or other supporting structure in a manner permitting the antenna to be securely maintained in the upright position while enabling the antenna to be pivoted into the horizontal position where it can be locked by a simple motion.
THE INVENTION
The invention resides in a mount for an antenna which permits the antenna to be securely maintained in an upright position and yet permits the antenna to be rotated or pivoted into a horizontal position when desired. The mount employs a base member having a cylindrical socket in which is disposed the cylindrical post of a swivel member. Rotation of the swivel member in the socket of the base is prevented by ribs on the bottom of the cylindrical post that seat in grooves in the floor of the socket. The ribs are maintained in engagement with the grooves by the force of a spring. To rotate the swivel member, it is necessary to overcome the spring force to the extent needed to move the ribs out of engagement with the grooves. The swivel member then can be rotated until the ribs come again into alignment with the grooves.
Carried upon the swivel member is a square post that can be slid into a square socket in the swivel member. The square post carries the antenna and when recessed in the square socket, the square post maintains the antenna in the upright position. By sliding the square post out of its socket, the post can be pivoted about an axle carried by the swivel member to swing the antenna into the horizontal position. Consequently, merely by exerting an upward force on the antenna, the antenna can be rotated or folded into the horizontal position or both rotated and tilted into the horizontal. When moved to the horizontal, the antenna can be locked in that position merely by causing the square post to rest upon ledges on the swivel member.
THE DRAWINGS
The invention, both as to its construction and its mode of operation, can be better understood from the detailed description which follows when it is considered in conjunction with the accompanying drawings in which
FIG. 1 depicts a typical antenna installation in which the invention can be employed;
FIG. 2 is an exploded view of the preferred embodiment of the invention;
FIG. 3 is a top plan view of the base of the preferred embodiment;
FIG. 4 depicts a cross-sectional view in elevation of the preferred embodiment of the invention in assembled form;
FIG. 5 is a bottom plan view of the swivel member showing its crossed ribs; and
FIG. 6 is an exploded view of the sliding post showing the bushing that is encased in the assembled post.
DETAILED DESCRIPTION
A typical antenna installation is depicted in FIG. 1 where the upright antenna 1 is supported at its base by a mount 2 secured atop a boat.
FIG. 2 is an exploded view of the antenna mount and shows the socket 3 in the base 4 that receives the cylindrical post 5 of the swivel member 6. The base is molded of a insulative synthetic material and has the exterior configuration of a truncated cone 7 disposed upon a circular pedestal 8. The pedestal, as shown in the top view of the base depicted in FIG. 3, has holes 9, spaced around its periphery for the passage of bolts to anchor the base to the supporting structure of a boat or land vehicle. The botton of the socket 3 in the base, as indicated in FIG. 3, has crossed grooves 10 which act as detents in cooperation with mating crossed ribs that protrude from the bottom of swivel member 6. At the junction of the crossed grooves, an aperture 11 is provided for the passage of a bolt 12, as shown in the cross-sectional view of the assembled mount depicted in FIG. 4.
The swivel member 6 has a truncated conical portion mounted upon and overhanging the cylindrical post 5. The conical portion is slotted to provide a pair of upstanding ears 13 and 14 that receive between tham a slidable square post 15. To permit post 15 to slide down into the swivel member, the swivel member is provided with a square socket 16. When the post is telescoped into socket 16, the post is rigidly held in the upright position. To permit post 15 to slide, it is provided with longitudinal slots 17 through which protrudes a shaft 18 whose ends are anchored in holes in the ears of the swivel member. To facilitate sliding of the square post, the longitudinal slots 17 have inclined sides providing ways that receive washers 19 which are of a material having a low coefficient of friction, such as Teflon.
When pulled out of the square socket, post 15 can pivot around shaft 18 in the slot between ears 13 and 14. Post 15 can, therefore, be swung in either direction from a vertical position to a horizontal position. When in the horizontal position, the post can be slid to cause it to span the socket and rest upon the ledges 20 and 20a. The post is thereby prevented from pivoting around shaft 18 and the antenna is effectively locked in the horizontal position.
The swivel member 6, as shown in the assembled view of FIG. 4, has its cylindrical post 5 held in the socket of base 4 by a bolt 12 that extends below the floor of the socket. A spring 21 on the shank of bolt 12, exerts a force tending to spread washer 22 and nust 23 apart. Consequently, a compressive force is exerted between washer 22 and the held of bolt 12 upon the interposed portions of base 4 and swivel member 6. The swivel member 6, as shown in the bottom view of that member depicted in FIG. 5, is provided with crossed ribs 24 that are dimensioned to fit into the crossed grooves 10 (FIG. 3) in the floor of the cylindrical socket in base 4. When the crossed ribs are engage in the crossed grooves, the swivel member 6 is locked to the base by the force of spring 21 and the swivel member then cannot be turned. By lifting square post 15, the swivel member can be moved sufficiently to disengage the crossed ribs from the crossed grooves and the swivel member can then be rotated around bolt 12 as the axis. Upon the swivel member being turned through 90°, the crossed ribs are brought into alignment with the crossed grooves and if permitted to engage, act as detents which prevent further rotation. Consequently, at each 90°To of rotation, a station is reached where the aligned crossed ribs and crossed grooves act as detents.
to permit nut 23 to be threaded onto the shank of bolt 12 and compress spring 21 without having the bolt turn, a bolt having a hexagonal head is employed and the floor of the square socket in swivel member 6 is provided with a matching hexagonal recess which accepts the head of the bolt and prevents the bolt from turning when the nut is tightened on the shank.
The swivel member, because of its relatively intricate shape, is preferably a molded member made of the same insulative synthetic material as the insulative base 4. When locked together, the swivel member and the base form a smooth sided trincated cone, as illustrated in FIG. 4.
The square post 15, as shown in the exploded view of FIG. 6, is a hollow member formed of two mating shell halves 25 and 26 that encase a metallic bushing 27. The bushing is preferably of brass or copper and is plated with nickel or a similar corrosion resistant material. The bushing has a square collar 28 that fits into recesses in the shell halves. The bushing has a central threaded aperture that receives the threaded shank of a whip antenna 29. A shielded cable 30 has its center conductor soldered or otherwise fastened to the bottom of bushing 27. The shielded cable extends through an aperture 31 in hollow post 15 to provide an exterior electrical connection to the antenna.
In use, the antenna is usually maintained in the vertical position by sliding post 15 downward into square socket 16. In the event it is desired to rotate the antenna, by lifting the antenna upwardly, the crossed ribs on the bottom of the swivel member can be lifted out of the grooves 10 in the base 4 and the antenna can then be rotated 90 before the detent members again engage.
To reduce the height of the antenna, as where a boat is required to pass under a low bridge, the antenna can be swung to a horizontal position by sliding the square post 15 upwardly out of its socket and then pivoting it around the shaft 18 into the horizontal. The antenna can then be locked in the horizontal position by sliding the square post to cause it to span the square socket and rest upon the ledges 20 and 20a.
Although a preferred embodiment has been illustrated in the drawings, it is evident that changes can be made that do not alter the essential nature of the invention. For example, the post 15 and the socket 16 need not be square. The post and socket can be of other shapes and still perform their intended functions. Further, the detents formed by the ribs 24 and the groove 10 can be interchanged in position and can be made to provide more than 4 stations, if desired.
In view of the different forms in which the invention can be embodied, it is not intended that the invention be limited to the precise structure depicted in the drawings. Rather, it is intended that the invention be delimited by the appended claims.