US1587022A

US1587022A - Drill jar

Info

Publication number: US1587022A
Application number: US694855A
Authority: US
Inventors: Gustavus A Montgomery
Original assignee: TITUSVILLE FORGE Co
Current assignee: TITUSVILLE FORGE Co
Priority date: 1924-02-25
Filing date: 1924-02-25
Publication date: 1926-06-01
Anticipated expiration: 1943-06-01

Description

June 1 1926.

G. A. MONTGOMERY DRILL'JAR Filed Feb. 25, 1924 Patented .lunev l, 1926. v

UNITED STATES PATENT OFFICE.

GUS'AVUS A. MONTGOMERY, OF TITUSVILLE, PENNSYLVANIA, ASSIGNOR TO TITUS- 'VILLE FORGE COMPANY, 0F TITUSVILLE, PENNSYLVANIA, A CORPORATION OF MARYLAND.

nmLr. JAR.

Application-med February 2,5, 1924. Serial No. 694,855.

This invention relates generally to the fishing and drilling tools employed in connection with oil well drilling operatlons, b ut more particularly to improvements in drill ars.

J Its chief object is to provide a tool of this character which is provided with a plurality of knocking heads and in which the parts of the jar are so constructed and arranged that they form a self-contained unit.

Another object of the invention is to pro vide a nonweldable jar which is strong and rugged in construction and efficient in o peration, and which is so constructed that its parts are prevented from swivelmg relatively to each other.

A still further feature of the invention resides in the novel method employedfor making the jar.

ln the accompanying drawings: Figure 1 is a fragmentary sectional elevation of a tool constructed in accordance with my invention. Figure 2 is a sectional elevation of the jar-body or cylinder. Figure 3 is a cross section on line 33, Fig. 1. Figure 4 is a cross section on line 4 4, Fig. 2. Figure 5 isa detached side elevation of the jar or plunger shown at .right angles to that illustrated in Fig. 1. Figure 6 is a fragmentary perspective view of the jar or plunger.

Similar characters of reference indicate corresponding parts throughout the several views.

The improved tool comprises two parts, viz: a jar-body or cylinder l0 closed at one end and open at its opposite end; and a plunger or jar 11 mounted to reciprocate in said jar-body. Extending from the open upper end of the jar-body to a point near the closed lower end thereof is a central bore preferably including a plurality of portions 12 substantially circular in cross section and a like number of portions 13 of cruciform or other similar shape in cross section, as shown in Figs. 3 and 4. These two portions of the bore are alternately disposed in axial alineme-nt as shown in Fig. 2, the uppermost cruciform bore-portion being located at the extreme upper end of the jar-body.4

By this arrangement, inwardly-facing shoulders or knocking heads 14 are provided at 'the junction or intersection of the

respective portions

12, 13, with one another, these shoulders being segmental or rib-like `in form due to the cross-sectional shapes of said portions. If desired, openings or slots 15 extending lengthwise of the jar-cylinder may be formed in the walls of the cylindrical portions 12 for thepurpose of permitting the entrance and discharge of mud, sanld, water, &c during the operation of the too The plunger or jar proper is shaped to fit the

portions

12, 13 of the jar-body. For this purpose, it is provided with a plurality of substantially cylindrical jar-portions or pistons 16 which are adapted to slidably engage the corresponding portions 12 of the jar-body, and a like number of channeled guide-portions 17 of -cruciform'shape in cross section which are adapted to slidably fit within the corresponding portions 13 of said jar-body. At the junction of the jar-portions with their guide portions are formed segmental shoulders or projections 18 which are adapted to strikeV the corresponding shoulders 14 of the jar-body during the relative reciprocation of the latter and the jar proper. The upper end of the latter is provided with the customary tapered attaching pin 19.

The method of making the jar cylinder and assembling the plunger jar within the same is preferably as follows:

After the4 jar-cylinder has been properly shaped as to its external dimensions, the same is bored and counterbored to produce the

corresponding portions

13, 12, the size of the main bore being approximately equalV to the diameter of the circle inscribed within the cruciform shaped portions 13 and the diameter of the counterbores being the same as that of the cylindrical portions 12. The main bore, it will be understood, extends from the open end of the jar-cylinder to the bottom of its-lowerm'ost cylindrical portion 12. The longitudinal slots 15 are. now cut in the diametrically opposite sides of the jar-cylinder and longitudinal saw slits 2O are also cut therein in line with said slots. The two halves of the jar-cylinder thus formed are then separated or distended into separated position, the portions 13 are then milled to such form that when the half-sections are brought together, such portions are substantially cruciform shape in cross section.

While the halvesof the jar-cylinder are in their distended position, the plunger is then placed therein with its jar portions 16 engaging the cylindrical portions 12 of said cylinder and its cruciform guide portions 17 fitting the corresponding portions 13 of the cylinder. The halves of the latter are now brought .together and permanently united by a ring 21 shrunk or otherwise fastened at 4the open end ot' the cylinder and by electrically welding the joints formed by the saw slits 20. This step coinpletes the assembling of the tool, and the same is now ready for use.

Both parts of the tool are preferably made of alloy steels which can be electrically welded but which are ordinarily not weldable in the blacksmith shop.

This improved drill jar is simple, yet strong and durable in construction and by making the jar-cylinder and jar-plunger in the manner herein shown and described, a plurality of knocking heads are provided which result in an increase in the area of the wearing surfaces of these parts and also prolong the life of the tool. Furthermore, the cruciforin cross section of the guide portions of the plunger and the corresponding portions of the cylinder adds materially to the strength of the tool and also prevents any swiveling action of its parts relative to each other.

I claim as my invention:

1. A tool of the character described, comprising a jar-body having a plurality of alternately arranged large and small bores disposed substantially in axial alignment,

the small bores being defined by segmental-v ly-shaped ribs forming internal knocking- 'heads between the respective bores, and a plunger having a plurality of alternately arranged jar portions and guide portions operating in said large and small bores respectively, the guide portions containing channels engaging the ribs of said small bores, the resulting shoulders formed between said jar portions and said channeled guide portions bein arranged for engagement with the knoc {ing-heads of said jarbody.

2. A tool of the character described, coinprising a jar-body having a plurality of alternately arranged bores of substantially cylindrical and cruciform shape in cross section, respectively, and Jforming segmental knocking-heads between them, and a plung-` er having a plurality vof alternately arranged jar portions and guide portions correspond-1` ing in cross section to the bores of said jarbody and operating in the saine, said plunger having segmental shoulders formed between the jar portions and the guide portions for engagement with the knocking heads of saidjar-body.

3. The method of making a tool of thev character described having a jar-body and a plunger including jar portions and guide portions of cruciform shape in cross section operable therein, which consists in forming alternately arranged large and sinall'bores' tions with its jar portions engaging the large bore of the jar-body and its guide portions engaging the cruciform-shaped bores of said jar-body, and then bringing said half-sections together about the plunger and uniting them. l

GUSTAVUS A. MONTGGMERY.