US2835975A - Range rod - Google Patents

Description

May 27 1958 N. J. ZIMMERMAN RANGE ROD Filed April 2:. 1955 W W m INVENTOR.

NEIL J. ZIMMERMAN ATTORNEY United States Patent RANGE ROD Neil J. Zimmerman, Fullerton, Calif.

Application April 21, 1955, Serial No. 502,781

3 Claims. (Cl. 33-74) The present invention is directed to a gimbal mounted surveyors range rod. More particularly the invention concerns a range rod having means for both short and long range surveying without the employment of a rodman to hold the rod.

Heretofore it has been the usual practice in the surveying field to have an assistant hold a range rod at the point being sighted by the surveyor through his transit. The surveyor must ordinarily give visual directions to the rodman to insure that the rod is being held in a vertical position, It has been suggested that range rods be supported in an adjustable tripod support by a gimbal mounting. The devices which have incorporated this suggestion have been extremely complex and expensive due to machined parts and attempts to make the devices extremely accurate. The main disadvantages of such gimbal mounted devices are that the gimbal mounted rods are aifected by windage preventing the rods from staying at a vertical position and that the rods are not adaptable for both long and short range surveying work. The range rod combination of the present invention provides a device which incorporates means to efiectively lock the range rod in a vertical position without lateral movement of the rod away from the marked station point, thus negating wind efiects. Furthermore, the range rod of the instant invention provides means, cooperating with a weighted tip member and the gimbal mount, to sight in at both short and long distances.

An object of this invention is to provide a simple construction for a gimbal mounted range rod.

A further object of this invention is to provide a gimbal mounted range rod having means to lock said rod in a vertical position.

A still further object of this invention is to provide a range rod combination adapted for sighting at both long and short distances.

An additional object of this invention is to provide a gimbal mounted range rod having an adjustable weighted tip portion and an extension thereon forming an auxiliary range rod adjusted for short distance surveying.

Other objects will be apparent from the hereinafter described device and the accompanying drawings in which Fig. 1 represents a side view of the gimbal mounted range rod;

Fig. 2 is a sectional plan view of the combination shown in Fig. 1;

Fig. 3 is a detailed view of the combination pivot and locking means of the invention taken in section on line 33 of Fig. 2;

And Fig. 4 is a partial cut-away drawing of the rod per se.

In the overall device shown, the range rod is mounted in a gimbal mount comprising a first ring means within which afirst tube 12 is pivotally mounted by pivot means 19 and 20, and asecond ring member 14,

2,835,9Y5 Patented May 27, 1958 split as at 14a (Fig. 2) to receive pivot means 19, within whichring 15 is pivotally mounted by pivot means 17 and 18 at right angles to the pivoting action oftube 12 andring 15. Tripod legs 11) are normally welded or otherwise attached to thering member 14 to support the entire structure. Extending from the lower end of thetube 12 is anadjustable tip portion 13 of sufiicient weight to insure pendulum action of said tube to adjust the tube automatically to a vertical position. Attached to thetip 13 is anextension member 16 extending concentrically through thetube 12 and of greater length than thetube 12. Themember 16 is guided or journalled in thetube 12 by an internal collar member 29 (Fig. 4) having a tapped hole for a thumb screw tip locking means 22, and by anupper collar 21 which also serves as a base to telescopically receive asecond tube 28 when it is desired that the range rod obtain a greater height. Succeeding telescoping tubes may be placed ontube 23. The exteriors of the tube members and theextension 16 are provided with indicia 12a and 16a to facilitate sighting thereon. in operation, theextension member 16 extending abovetube 12 provides a short range sighting rod perfectly aligned vertically with thetube 12 by reason of theweighted tip 13 and the gimbal mount. Thetube 12 orextension 28 mounted thereon, each of greater diameter than therod 16, provide a range rod adapted for long range work.

Fig. 1 further discloses a particular usage of the range rod combination in which thetip portion 13 is adapted to be lowered, by slackingscrew 22, on to astation point 24 in arecessed opening 23. when the tip and itsextension member 16 is lowered ontopoint 21 theextension member 16 still extends from the top end oftube 12 enabling close tolerance sighting thereon.

As seen in Fig. 2 thetube 12 andring 15 are gimbaled by pivot means 17, 18, 19 and 21). Pivot means 18 and 29' are stud members rigidly afiixed to thering 14 andring 15, respectively. The pivot means 17 and 19 are adjustable so as to lock the girnbal arrangement without lateral movement of the tube or the inner ring.

Fig. 3 illustrates in detail the combined locking and pivot means. The pivot means 17 and 19 each are journalled through thering members 14 and 15, respectively. As seen in Fig. 3, the pivot means 17 has aconical pivot point 26 and ashoulder portion 27, the pivot point normally seating on the side of aconical notch 25 in thering 15. The gap between theshoulder portion 27 and the exterior surface of thering 15 is overemphasized for illustration purposes. When it is desired to lock thetube 12 orring 15 in position, themeans 17 and 19 need be rotated only a slight amount to frictionally engage the shoulder portions with peripheral surfaces of the tube means 12 andring 15. Due to the extremely small movement of thepoint 26 on the incline of thenotch 25, canting of the tube from a vertical position is virtually eliminated. Lateral movement of thetube 12 or thering 15 is completely prevented, insuring thattip portion 13 remains accurately over the station point.

Although the invention has been described and illustrated in detail, it is to be clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of this invention being limited only by the terms of the appended claims.

I claim:

1. A range rod combination comprising a first tube, a support, means to girnbal mount said tube on said support, an extension member extending concentrically within and from the ends of said first tube, a tip portion attached to one end of said member, and a second are placed on said tubes and on said extension member.

3. The invention as set out in ciaim l in which a bored collar means is provided onone end of said first tube through which the extension member is guided and over 7 which the second pipe is telescoped.

References Cited in the file of this patent UNiTED STATES PATENTS Lafon M Dec. 18, 1906 Miner et alj Oct. 9, 1934 FOREIGN PATENTS Germany Sept. 18, 1891 Italy Apr. 17,1935

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