US 2214685 A
Description (OCR text may contain errors)
Sept. l0, 1940. 1 .sToNE,JR
AUTOMOBILE ANTENNA Filed June '7, 1938 INVENTOR. Aww/V615 o/vfJ/.z BY Y I MdKTORNIAH Patented Sept. 10, 1940 UNITED STATES PATENT OFFICE Claims.
Other objects of the invention are to providel signal means which will notify the driver whether the antenna is in the vertical or folded position; to provide means for minutely and accurately adjusting the length of the antenna so that it may be accurately tuned into the input circuit of the radio; and to provide latch means which hold the antenna rigidly vertical until it contacts an obstruction to prevent its being folded by the wind.
Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efciency. These will become more apparent from the following description.
In the following detailed description of the invention reference is had to the accompanying drawing which forms a part hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.
In the drawing:
Fig. 1 is a perspective View illustrating the invention in place upon an automobile.
Fig. 2 is a vertical section therethrough.
Fig. 3 is a detail view illustrating the mounting bracket of the antenna.
Fig. 4 is a detail section through the signal switch illustrating its association with the an- 40 tenna.
Fig. 5 is a detail view illustrating an alternate form of the antenna in which the projected length thereof may be adjusted.
In Fig. l a typical automobile is indicated at ID, The improved antenna may be attached at any desired position on the automobile I0. It is preferred to attach it to the forward mid-position of the roof as illustrated.
The antenna is supported from a base plate I I which can be attached to the automobile in any desired manner. Two supporting arms I2 extend upwardly from the base plate I I to pivotally support the antenna proper.
The antenna consists of a tip member I3 which is telescopically slidable within a tubular inter- (Cl. Z50-33) mediate section I4. The intermediate section I4 is also telescopically slidable Within a lower insulating tube section I5.
The lower section I5 is formed of bakelite, hardfrubber, fiber, or other electric insulating material and is mounted by means of a pair of clamp members I S clamped thereto by means of suitable clamp bolts I'I. Each of the bearing members carries a bearing stud I3 which is rotatably mounted in a bearing in one of the 10 arms I2.
A compression spring I9 in the section I4 constantly urges the tip member I3 upwardly. The outward movement thereof is limited by means of an enlarged extremity 20 which contacts a cap 15 member 2l.
The intermediate section I4 is constantly urged upwardly by means of a compression spring 22 positioned within the tube I5 and contacting an enlarged extremity 23 on the-section I4.
The lower extremity of the section I5 carries a counter-weight 24 which partially closes the tube I5 at the bottom thereof to provide a shoulder for the support of the spring 22. The counter-weight 24 is of suiilcient weight to maintain 25 the entire antenna vertical.
An antenna lead wire 25 extends through the base plate II into the tube I5 where it connects with a tension spring 26 which extends upwardly to a connection with the intermediate sec- 30 tion I4.
The spring 2B acts to maintain the lead wire 25 tight at all times to prevent bending or wrinkling thereof, but is not strong enough to collapse the spring 22. The purpose of the insulating tube 35 I5 is to position the metallic portion of the antenna abov'e the metallic top of the automobile ID to avoid the shielding eiect of the latter.
It can be readily seen that, as the automobile is driven under a low obstruction such as through 40 the doorway of a building, the entire antenna will fold or tilt backwardly, as indicated by the broken lines in Fig. 1. After the obstruction is passed, the weight of the counter-weight 24 assisted by the tension spring 26 will immediately 45 bring the antenna to a vertical position. Should the car be backed while the antenna is in the folded back position, the section I3 will be forced into the section I4 and the section I4 will be forced into the tube I5 allowing the car to pass 50 under the obstruction after which the tubes will spring back to position and the antenna will resume its vertical position.
For police cars, the antenna circuits must be accurately tuned with the radio for the desired 55 wave band. A slight increase or decrease in the length of the antenna effects the resonance of the receiver to and from the desired broadcast band. Therefore means are provided, as shown in the alternate form of Fig. 5, for obtaining an accurate adjustment of the length of the metallic portion of the antenna so that the input circuit may be tuned to proper resonance. This is accomplished by employing a tapered tip-section 2l and splitting the upper extremity of the intermediate section as indicated at 2S. A cap member 35, the interior of which is taper threaded engages the upper extremity of the intermediate section. As the cap member is tightened, it squeezes the split extremity inwardly so that it will engage the taper of the tapered tip section 2 at any desired point to limit the upward movement of the tip section. Therefore, by tightening or loosening the cap member 35, the overall length of the entire antenna may be accurately and minutely pre-set.
t is also very essential in police work that the operator be informed at all times whether the antenna is in the vertical receiving position so that he will know his receiving set is in condition for receiving incoming signals. This is accomplished in the present invention by providing a signal circuit which operates whenever the antenna is folded to give an indication thereof to the operator.
In the particular embodiment illustrated, a press button switch member '3a is mounted below the counter-weight so as to be contacted thereby when the antenna is in the vertical position. The switch member 2Q closes contact between a pair of Contact members whenever it is released by the swinging of the antenna from the vertical position. These contacts are in circuit with an indicating light 3l, or an audible indicator 32, so that the operator will be immediately informed that the antenna is down.
It is preferred to have the head of the switch member rounded and to provide a receiving depression 33 on the counter-weight into which the head will be forced by means of a switch spring 3d when the antenna is vertical. This enables the switch to serve a double purpose since it also acts as a resilient latch member to hold the antenna vertical and to prevent it from swinging or swaying in the wind until it actually strikes an obstruction.
While the invention has been described as a receiving antenna, it forms an unusually efiicient sending antenna where two-way radios are employed. Should the antenna be in the folded position, broadcasting would be impossible due to the shielding effect or" the roof. Therefor the signal is especially valuable in broadcasting.
While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention.
Having thus described the invention, what is claimed and desired secured by Letters Patent is:
l. A radio antenna for automobiles comprising: a base member; oppositely positioned bearings supported from said base member; a rst tube extending upwardly from said base member and mounted in said bearings so that it may swing in a vertical plane; a second tube telescopically slidable within said rst tube and extending upwardly therefrom; spring means for holding said second tube in the extended position; a counter-weight mounted on the lower extremity of said first tube below said bearings to act by gravity to hold said tubes in the vertical position; a switch member positioned to be opened by contact with said counterweight when said antenna is in the vertical position; and a signal device in circuit with said switch member to give an indication when said antenna is other than vertical.
2. A radio antenna for vehicles comprising: a base member; bearings carried in two oppositely positioned supporting arms extending upwardly from said base member; an antenna member mounted in said bearings so that it may swing in a vertical plane; a reciprocal weight mounted on the lower extremity of said antenna member below said bearings to act by gravity to hold said antenna in a vertical position; an antenna lead wire extending upwardly into said antenna; and a tension spring in electrical series with said wire for maintaining said wire taut.
3. A vehicle radio antenna comprising: a bearing bracket member for attachment to said vehicle; an elongated antenna member hingedly mounted intermediate its extremities in said bracket to swing in a vertical plane; a counterweight rigidly secured to the lower extremity of said antenna member to maintain the latter normally Vertical; a headed plunger member; and spring means for urging the head of said plunger member into the path of movement of said counterweight, the latter having means for receiving said head when said antenna is in the vertical position, to resist swaying of said antenna member under the movement of said vehicle.
a. A vehicle radio antenna comprising: a bearing bracket member for attachment to said vehicle; an elongated antenna member hingedly mounted intermediate its extremities in said bracket to swing in a vertical plane; a counterweight rigidly secured to the lower extremity of said antenna member to maintain the latter normally vertical; a headed plunger member; spring means for urging the head of said plunger member into the path of movement of said counterweight so that contact with the latter will depress said plunger; switch means, said switch means being actuated by said plunger so as to be opened when the latter is depressed by said counterweight and closed when said counterweight swings out of Contact with said plunger; and a signal circuit including said switch means for giving a signal when said switch means closes.
5. In a vehicle radio antenna of the swinging, counterweight type, means for resisting swaying of said antenna and for giving a signal when lthe latter inclines from the vertical comprising: an indented projection on the counterweight; a plunger having a rounded head positioned to engage the indentation in said projection when said antenna is vertical; a spring urging said plunger toward said counterweight; a switch; and switch closing means carried by said plunger and positioned to close said switch when said plunger is out of Contact with said counterweight.
LAWRENCE STONE, J R.