US2218319A

US2218319A - Adjustable extension

Info

Publication number: US2218319A
Application number: US277155A
Authority: US
Inventors: Edward M Pfauser
Original assignee: Blackhawk Manufacturing Co
Current assignee: Blackhawk Manufacturing Co
Priority date: 1939-06-03
Filing date: 1939-06-03
Publication date: 1940-10-15
Anticipated expiration: 1957-10-15

Description

Oct. 15. 1940- E. M. PFAusER AUJUSTABLE EXTENSION Filed June 3, 1939 2 Sheets-Sheet l n ,so y

a yy 'MTNEYQS V06f. 15, l940- E. M. PFAl-JsER 2,218,319

ADJUSTABLE EXTENS ION Filed June 3, 1959 2 Sheets-Shee. 2

ATTORNEY y Patented Oct. 15, 19 40 UNITED STATES PATENT oEFlcE 2,218,319 ADJUSTABLE EXTENSION Edward M.'Pi'auser, Elm Grove, Wis., assignor to Blackhawk Minco., Milwaukee, Wis., a corporation of Wisconsin Application June 3, 1939, Serial No. 277,155

` 14 claims. (o1. asi-98)' ject upon which work is being performed.,

Generally stated, an object of the present lvention is to provide an improved adjustable exo tension which may be quickly and convemently elongated or shortened, and which is positively retained in adjusted condition.

When utilizing mechanical or iiuid pressure becomes desirable to quickly vary or adjust the length of the pressure transferring and sustaining prop or connection between the jack mechanism and the object upon which the work is being performed.` Many different types of these quick adjustable jack extensions have heretofore been proposed and used with somesuccess, the prior devices have all been relatively objectiony able either because of their complicated and bulky construction, 'or because they were ineffective in actual use. In some of the more populai jack extensions of this type, variation in `length was obtained by utilizing a quickly releasable friction clamp coacting with the extension bar or spindle, and while this type of extension was relatively satisfactory when the pressure acting upon the opposite ends thereof was not too great, it would not positively resist extreme pressures andthe ble prop which may be readily manufactured at moderate cost, and which may-also be utilized as Y a. mechanical jack assemblage.

A further specic object of this invention is to provide an 4extremely sturdy and simple adjustable jack extension, which: may be quickly and conveniently elongated or shortened to fit within a xed space, wherein 'the relatively adjustable parts may be more slowly and accurately displaced by means of a screw thread, and in which vsemblage of Fig.'1, taken along the line 3 3;

the parts are finally positively held in adjusted position against possible displacement.

Still another specic object of myinvention is to provide a new and useful adjustable pressure sustaining prop, whereinnthe pressures are most l electively resisted by the prop elements and in which the adjusting notches or threads may be easily formed with thread chasers.

These andother specific objects and advantages will be apparent from the following detailed 10 description. l

A clear conception of several embodiments of my present invention, and of the mode of constructing and of manipulating adjustable exten-` sions built in accordance with my improvement, Il

may be had by referring to the drawings accompanying and forming apart of this speciiication wherein like reference characters designate' the same or similar parts in the varioustviews.

Fig. 1 is 'a central longitudinal section through 20 one type of my improved adjustable extensions, showing the relatively adjustable elements positively interconnected and in condition to resist end pressure;

Fig. 2 is a similar sectionthrough a portion of 25 the assemblage of Fig. 1, but showing the relatively adjustable elements disconnected preparatory to adjustment;

Fig. 3 is a transverse section through the as- 30 Fig. 4 is a transverse section through the cori-` necting block or member alone, depicting the method of producing this member;

Fig. 5 is a central longitudinal section through another type of the improved adjustable exten- 35 sion, showing the parts positioned as in Fig. 1;

Fig. 6 is a similar section through a fragment of the assemblage of Fig. 5, with the relatively adjustable parts disconnected;

Fig. -7. is a transverse section through the assemblage of Fig. 5, taken along the line 1 1; and

Fig. 8 is a transverse section through the modified connecting block of Figs. 5 to 7 inclusive.

8 along the major portion of the length thereof; an outer element or housing 9 having an internal bore embracing but freely movable along and around the crests of the threads 1 of the spindle 6; and a connecting member or block I0 laterally slidably confined within a pocket II in the housing 9 and having partial internal threads I2 forming transverse lateral projections which are adapted to interlock with the notches 8 formed by the spindle threads 1.

The spindle 6 may be of any suitable length and may also be either solid or hollow depending upon its diameter, and one end of the spindle 6 may be provided with a detachable externally threaded head or sleeve I4 which may be firmly but removably attached to the spindle end-by a drift pin I5. A work engaging member I6 of any desired type, may be detachably secured to the external threads I1 of the spindle 6 as shown in Fig. 1, but it should be apparent that the sleeve I4 may be omitted and' that the work engaging member may be applied directly to the 'spindle y end.

The housing 9 which is adjustable along the spindle 6, is of durable construction, and has one end socketed and provided with internal screw threads I8 for reception of the threaded end of a tubular member or pipe I9 of any-suitable length. Ordinarily, the opposite end of the pipe I9 is also threaded for coaction with the end of one of the movable elements of either a hydraulicor a mechanical jack, or the opposite threaded pipe end may be attached to another work engaging member I6 when the device is employed merely as a shore or prop. The exterior of the socketed lend 20 of the housing 9 may be formed polygonal, as for instance hexagonal as shown inFlg. 3, in order to facilitate application of a wrench, but this formation is not essential.

The interconnecting block I which is slidably confined within the housing pocket II as shown in Fig. 3, is of rectangular shape, and is normally urged toward the spindle 6 so as to cause the .block projections or threads I2 to enter the spindle notches 8 as in Fig. l, by means of a pair of helical compression springs 2l coacting with recesses 22 in the block I0 and reacting against al closure plate 23 secured to the housing 9 over the pocket II by means of drive screws 24. The end of the threaded spindle 6 remote from the sleeve I4 may be provided with a stop pin 25 which is engageable with the corresponding side of the block I0 in order to prevent accidental complete separation of the housing 9 and spindle 6 during relative quick adjustment of these elements.

During manufacture of the blocks i8, and in order to insure sufficient strength and desired accuracy in the formation thereof, these blocks are preferably produced from solid metal blocks having the desired size and shape. Each block is. preferably initially bored and internally threaded as indicated by the dot-anddash circles 25 in Figs. 4 and 8, after which the block may be set in a jig and finally bored o ifcenter along the circle 26. The diameter of the nal bore is somewhat larger than the larger diand the recesses 22 may be formed either before or afte'r the blocks Il! are bored.

When my improved adjustable extension has been properly constructed and assembled, a work engaging member I6 of any desired type, may be applied to the threaded sleeve I4, and a pipe I9 of any desired length may be applied to the inin conjunction with Ja hydraulic ram or a jack, the end of the pipe I9 remote from the housing 9 may be connected to one of the relatively movable elements of the ram or jack. The overall length of the jack and extension may then be quickly adjusted to initially roughly fit the vwork, by merely pressing the block I0 against the springs .2| until the thread projections I2 are disengaged from the'notches 8 of the spindle thread 1 as in Fig. 2, and by thereafter sliding the block I8 and housing 9 as a unit along the spindle 8 in either direction until the work engaging faces of the jack and of the member I6 are in approximately the desired position. The block I0 may thenbe released to permit the springs 2I to return the same to interlocking position as shown in Fig.`1, and more accurate final adjustment of the length of the assemblage may then be secured by relatively rotating the housing 9 and spindle 6 to cause the block I0 to revolve about the spindle threads 1. When the desired length of the assemblage has been thus finally obtained, pressure may be applied tothe end of the pipe I9 -in order to perform the work, and this pressure will be positively'transmitted through the housing 9, block I0,l spindle B, sleeve I4, and member I6 to the pressure receiving object, without danger of slippage-between the extension elements.

Since the block I0 of the assemblage shown in Figs. 1 to 4 inclusive cannot be readily finished internally with a screw thread chaser, due to the use ofsquare threads, it may be desirable to form the screw and block as shown in the modified assemblage of Figs. 5 to 8 inclusive. This modied assemblage comprises a spindlel 6' havling externalY screw threads 1 of the acme type having included'angles of approximately 29 and providing a series 'of transverse tapered notches 8' along the major portion of its length; a housing 9' embracing but movable freely along and about the crests of the threads 1'; and a block I0 slidably confinedin an inclined pocket II' in the housing 9' and having partial internal threads /I 2 forming transverse tapered projections adapted to interlock with vthe notches 8' formed on the spindle 6. In constructing the modified assemblage, the inclination of the pocket II relative to a plane perpendicular to the spindle axis, should preferably be one-half of the included thread angle, so that when pressure is applied to the ends of the prop, this pressure will be transmitted from the spindle 6' to the block I0 and from the latter to the housing 9' without forcing the block away from the spindle. For example, if the included angle of the threads 1 is twenty-nine degrees, the angle of inclination of the pocket II' shouldbe fourteen and onehalf degrees. In other respects, the construction and operation of the modified assemblage is substantially like that of Figs. l to 4 inclusive, but

` the modified structure is susceptible of being more tei-nal threads I8. If the device is to be utilized in the extension itself. The thread projections of the interconnecting block may, in each case, be readily and accurately formed, and serves to positively interconnect the housing and spindle when the springs I2 are effective. This block may, however, be quickly and conveniently released from the spindle so as to permit relative adjustment of thespindle and housing, and by virtue of the fact that the projections I2, I2' are actual portions of true screw threads, the housing mayalso be rotated about the spindle for purposes of finer adjustment. The modified thread projections I2 may be .readily formed with a thread chaser, and will eiectively transmit pressure without slippage. As previously indicated, the improved assemblage may be utilized either as a jack for creating and applying pressure, or as an extension for a ram or jack, or as a shore or prop. The assemblage can be accurately machined at relatively low cost, so `as to insure most eiiicient operation thereof, andhas actually proven highly successful in commercial use. As heretofore indicated, the work engaging member I6 may be of any desired type, and the intermediate pipes I9 may be of any desired length.

It should be understood that it is not desired to limit this invention to the exact details of construction or to the precise mode of use, herein shown and described, for various modiilcations within the scope of the claims may occur to persons skilled in the art.

I claim:

1. An adjustable extension comprising, an elongated element having notches 'extending in series therealong, a housing element embracing said elongated element and being movable therealong, and a member having an opening through which said elongated element is freely axially movable,

said member being slidable Within said housing element laterally of said elongated element and having a series of projections at one side of said opening interlockable with said notches to positively connect said elements.

2. An adjustable extension comprising, a-n elongated element having a screw thread forming notches extending in series therealong, a housing element embracing said elongated 'element and being rotatable `thereaboutand movable therealong, and a member having a bore through which said elongated element is freely axially shiftable, said member being slidable within said housing element laterally of said elongated element and having a series of projections at one side of said bore interlockable `with'said notches elongated element and having an opening through which said element is freely axially movable, said member being slidable within said housing element laterally of said elongated element and having a series of projections at one side of said opening interlockable with said notches to positively connect said elements, and resilient means for constantly urging said member toward interlocking position.

4. An adjustable extension comprising, an

elongated element having a screw thread forming notches extending in series therealong, a housing element embracing and being rotatable there'about and movable therealong, a member completely surrounding said elongated element and having an opening through which said .element is freely' axially shiftable, said member being slidable within said housing element laterally of said elongated element and having a series of projections at one side of said bore interlockable with said notches and rotatable about said screw thread to posisaid elongated element` tively connect said elements, and spring means Y for constantly urging said member toward interlocking position.

5. An adjustable extension comprising, an elongated spindle having an external screw thread,

a housing embracing said spindle and having a.

pocket therein, and a block slidably confined within said pocket and having a bore provided withpartial threads at one side only of said bore and engageable with said spindle threads to interlock said spindle and housing, said bore being large enough to permit said block to be slid-away from said spindle sufficiently to interrupt the interlock and to permit relative sliding of said housing and spindle.

6. An adjustable extension comprising, an

elongated spindle having an external screwthread, a housing embracing said spindle and having a pocket therein, a blocklslidably conned within said pocket and having a bore provided with partial threads at one side only of said bore engageable with said spindle threads to interlock said spindle and housing,'said block completely surrounding said spindleand said bore being of sufficient diameter to permit said block to be slid away from said spindle suiciently to interrupt the interlock4 and to permit relative sliding of said housing and spindle, and a spring for constantly urging said block toward interlocking position. y

' 7. An adjustablev extension comprising, an

elongated externally threaded spindle having screw threads at one end forl interchangeable attachment of work engaging members, a housing embracing said spindle and having screw threads.

adapted for interchangeable reception of pressure applying pipes of ydifferent lengths, anda block completely surrounding said spindle and being slidably confined withinl said housing, said block having a bore and projections at one side only of said bore. engageable with the screwthreads on said spindle for locking said housing in adjusted positions.

8. An adjustable extension comprising, an elongated element having a series of transverse tagated element having a series of transverse tapered notches along a side thereof, a housing element -movable longitudinally of said elongated element and a connecting member slidable relative to said housing element and laterally of said elongated element at an oblique angle, fsaidmember having tapered projections interlockable with said notches and the angle of sliding of saidv member being approximately one-half of the ineluded angle of the taper of said notches and oi' said projections.

10.v An adjustable extension comprising, an elongated element having V-shaped screw threads forming tapered notches' extending in series therealong, a housing element embracing said elongated element, and being, rotatable thereabout and movable therealong, and a member slidable Within said housing element laterally of said elongated element and at an oblique angle relative to the longitudinal axis ofsaidI elongated element, said housing member having tapered projections interlockable with said notches'and rotatable about said threads.

11. A'n adjustable extension comprising, an yelongated element having V-shaped screw threads forming tapered notches extending in series therealong, a housing element embracing' said elongated element and being rotatable thereabout and movablel therealong, and a member slidable within said housing element laterally of said elongated element and at an oblique angle'` relative to the longitudinal axis of said elongated I\element, said slidable member having tapered 'projections interlockable with said notches and rotatable about said threads and the angle of sliding of said member relative to said elongated element being approximately one-halfof the included a-ngle of said threads.

' 12. An adjustable extension comprising, an elongated element having screw threads forming tapered notches extending in series therealong,

a housing element embracing-said elongated element and being revolvablc thereabout and movable therealong, and a member having a bore through which said elongated element extends and being slidable within said housing element laterally of said elongated element and approximately parallel to the planesof corresponding sides of said notches. v

13. An adjustable extension comprising, an elongated element having a series of tapered notches at one side thereof, a housing element movable along said elongatedelement, and a member `slidable Within said housing element laterally of said elongated element and at an oblique angle relative to the longitudinal axis of the later, said member having tapered projections cooperable with said notches ,and being movable approximately parallel to the Iplanes of the corresponding pressure resisting sides of said notches.

14. An adjustable extension comprising, an elongated screw' threaded element, a housing element movable along said elongated element, and a memberA having a bore through which said elongated element extends and which is provided with local projections cooperable with corresponding portionsr of the successive screw threads of said elongated element, said 'member being slidable in said housing element laterally of said threaded element and in a plane approximately parallel to corresponding sides of the successive threads.

EDWARD M. PFAUSER.