US3322450A

US3322450A - Adjustable roller latch

Info

Publication number: US3322450A
Authority: US
Inventors: Fred J Russell; Richard L Armstrong; Harold W Falk
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-09-21
Filing date: 1964-09-21
Publication date: 1967-05-30
Anticipated expiration: 1984-05-30

Description

May 30, 1967 F. J. RUSSELL ETAL 3,322,450

v ADJUSTABLE ROLLER LATCH Filed sept.v 21, 1964 2 Sheets-Sheet l May 30, 1967 F. J. RUSSELL ETAL 3,322,450

ADJUSTABLE ROLLER LATCH Filed Sept. 2l, 1964 2 Sheets-Sheet 2 .Z'A/l/Eurc/@S /QED drlgasszaz., gc/MPU L. /QMSreaA/G, Hww WMM,

United States Patent O 3,322,450 ADJUSTABLE RGLLER LATCH Fred J. Russell, 8635 Otis St., South Gate, Calif. 90280, and Richard L. Armstrong, Santa Fe Springs, and Harold W. Falk, Los Angeles, Calif.; said Armstrong and said Falk assignors to said Russell Filed Sept. 21, 1964, Ser. No. 397,904 4 Claims. (Cl. 292 75) This invention relates generally to door latch mechanisms, and more particularly to roller latch units, the installation and operational adjustment of which is -facilitated.

This invention finds its most important use in connection with doors, windows, drawers, and the like members which are to be releasably latched in closed, opened, or other predetermined positions.

Heretofore, in the installation of such latching devices in doors or the like swinging or moving members, complicated and time consuming installation operations have usually been necessary. Additionally, once such latch mechanisms had been installed in the usual concealed location within the edge portion of a door or the like member, subsequent necessary adjustment of the clearance and action of the latch for proper engagement with a suitable detent or catch-means usually could not be accomplished without removal of the entire unit from the door.

It is accordingly, a-n object of this invention to provide a new and improved latch mechanism for doors and the like members.

It is another object of this invention to provide a latch unit which lends itself to simplified and rapid installation in doors and the like members.

It is still another object of this invention to provide an improved latch unit which can be easily and quickly adjusted for proper clearance and engagement with a detent device in an adjacent door jamb, window frame, or the like companion member without the necessity of removing the unit from the member in which it is installed.

It is a further object of this invention to provide a new and improved adjustable roller type latch unit.

:Other objects, advantages, and features of novelty of the invention will be evident hereinafter.

In the drawing, in which a presently preferred embodiment of the invention is illustrated and in which like reference characters designate the same or similar parts throughout the several views;

FIGURE 1 is a fragmentary, perspective view of the 4adjustable latch unit assembly as it appears in a typical installation in the edge of a door;

FIGURE 2 is .an enlarged, longitudinal sectional View of the apparatus of the invention taken on line 2 2 of FIGURE 1; i

FIGURE 3 is an end elevational view of the apparatus .as viewed from line 3 3 of FIGUR-E `2;

FIGURE 4 is a cross sectional view of the latch assembly taken on line 4 4 of FIGURE 2;

FIGURE 5 is a longitudinal sectional view similar to FIGURE 2 but showing the apparatus substantially as it would appear if viewed from line 5 5 `of either FIGURE 1 or of FIGURE '2, and showing a typical dete-nt device installation in connection therewith;

FIGURE l6 is an exploded, perspective, detailed View of the separate elements of the apparatus of FIGURES l, 2, and 5;

FIGURE 7 is an enlarged, end elevational view of an element of the apparatus taken from line 7 7 of FIG- URE 6.

Referring lnow to the drawings in more detail, the external housing portion of the roller latch unit indicated ICC generally at 10, comprises an elongated, open-ended, cylindrical case 12 formed at its outer end with a radially extending front flange 14, which is generally annular in shape except for a pair of diametrically opposite rectangular anchor notches 16 and 18 therein, and a pair of diametrically

opposite flats

20 and 22 formed thereon. The inner end of the case 12 is provided with a radially inwardly extending rea-r flange 24 which is also generally annular in shape except for a pair of diametrically opposite, radially inwardly extending

key tabs

26 and 28.

In the assembled apparatus, as shown in FIGURE 2, the case 12 extends inwardly through a circular opening 30 centrally located in an anchor plate 32, with the inner surface of the front flange 14 in abutment with the marginal portion of the outer face of the anchor plate 32, surrounding the circular opening 30. The anchor plate 32 is provided with a pair of diametrically

opposite anchor tabs

34 and 36, which are bent forwardly from the plane of the anchor plate material such as to engage the beforementioned anchor notches 16 and 18, respectively in the front flange 14. The anchor plate 32 is also formed with a pair of forwardly rolled,

opposite edge portions

33 and 35, which fit over and engage the edges of the

beforementioned flats

20 and 22 of the front flange 14. The case 12 and anchor plate 32 are thereby locked together against relative rotation about their common longitudinal axis illustrated in broken lines at 38. The case 12 and anchor plate 32 when assembled, las shown in FIGURE 2, are fastened in the before described assembled and lockedtogether positions by means of a generally rectangular escutcheon plate 40, which covers the outer face of the `anchor plate 32 and engages the outer face of the front dlange 14 of the case 12. The front flange 14 of the case 12 is thus securely clamped between the anchor plate 32 and the escutcheon plate 40, such clampi-ng and also the retention of the unit as a whole in 'a door or the like member 120, being accomplished by a pair of

suitable attachment screws

42 and 44, which pass through

screw holes

46 and 48 in the escutcheon plate 40 and correspondingly aligned

holes

50 and 52 in the anchor plate 32. The escutcheon plate 40 is provided with a central opening 53, the center of which is coaxial with the aforementioned longitudinal axis 38, such opening having a special shape, which will hereinafter be more fully described.

The internal mechanism of the latch unit 10 which is mainly contained within and extends axially through t-he before described external housing portion of the unit including case 12, comprises a plunger assembly shown generally at 54, a plunger positioning annular nut 56, a plunger position adjusting bushing 58 and a plunger drive spring 60.

The plunger :assembly 54 comprises an outer plunger -head portion 62 and a coaxially inwardly extending plunger shaft portion 64 fixed thereto. The plunger head portion 62 is generally cylindrical in external shape, having an outside diameter such as to make a free sliding fit within ythe inside diameter of the case 12. The forward or outermost end portion `of the plunger head portion 62 is bifurcated, thereby forming a pair of parallel, forwardly extending, latch

roller supporting arms

66 and 68, the upper and lower outer

curved surfaces

70 and 72 of which, as best shown in FIGURES l and 6, are coextensive with the cylindrical outer surface of the plunger head portion 62. The

arms

66 and 68 are formed with opposite, inwardly confronting flat surfaces separated from one another such as to receive therebetween a rotatable latch roller 74. The latch roller 74 is rotatably retained between the said inner flat surfaces of the

roller supporting arms

66 and 68, by means of a bearing pin 76 which extends diametrically crosswise through bearing holes 75 3 and 77 in the

arms

66 and 68. The bearing pin 76 is slightly shorter than the outside diameter of the outer surfaces of the latch

roller supporting arms

66 and 68 and is rotatably retained therein by forming the midsection of the bearing pin 76 with an outside diameter making a firm press fit within the bore of the latch roller 74.

The outer portions of t-he latch

roller supporting arms

66 and 68 are formed on opposite sides thereof with at edge surfaces, such surfaces being shown at 78 and 80 on the upper arm 66, and at 82 and 84 on the lower arm 68, such surfaces thereof being parallel with each other and with both the longitudinal axis of the plunger head and the longitudinal axis of the roller bearing pin 76. Forwardly facing

shoulders

86, 88, 90 and 92 are thereby formed at the junctures of the

beforementioned fiat surfaces

78, 80, 82 and 84, and lthe adjoining non-flat root portions of the supporting

arms

66 and 68. In the assembled apparatus, as best shown in FIGURE 2, the plunger assembly 54 is in its maximum extended position with the plunger head portion 62 in the outer end portion of the cylindrical case 12 and with the outer ends of the latch

roller supporting arms

66 and 68 and the latch roller 74 therein, extending -outwardly a suitable distance through and beyond the outside surface of the escutcheon plate opening 53. As is most apparent from FIGURES 1 and 6, the escutcheon plate opening 53 closely conforms to the exterior transverse sectional contour of the outer end portion of the

arms

66 and 68 and the latch roller 74, whereby in the extended position as shown, the plunger head portion 62 is axially slidable, but nonrotatable in the escutcheon plate opening 53.

More specifically, the form of the escutcheon plate opening 53 is defined by a pair of opposite, upper and lower recessed portions 93 and 94, having arcuate end edges 96 and 98 corresponding in shape with but makin-g slight clearance with the opposite curved surfaces 70 and '72 of the latch

roller supporting arms

66 and 68, and with the widths of such recessed portions 93 and 94, corresponding to the widths of the latch

roller supporting arms

66 and 68 between their opposite

flat surfaces

78, 80, 82, and 84. The escutcheon plate opening 53 is also defined by another pair of horizontally opposite, recessed porti-ons, 100 and 102, the outer end edges of which are separated from one another forming an opening having a crosswise dimension slightly greater than the outside diameter of the latch roller 74 and an effective vertical width corresponding to the length of the latch roller 74. Thus, as beforementioned, the outer end portion of the plunger head 62 along the length of the

flat edges

78, 80, 82 and 84, outwardly of the

shoulders

86, 88, 90 and 92, axially slidably fits the shape of the opening 53 thus formed, and is thus axially slidably supported but restrained from rotation within the outer end portion of the case 12, the maximum possible outward extending movement of the plunger head portion 62, being limited either by abutment of the

aforementioned shoulders

86, 88, 90 and 92 with the inner surface portion of the escutcheon plate 40, adjacent the opening 53 therein, or more normally by other limiting means as hereinafter described.

The plunger shaft 64 has a non-round cross section, preferably hexagonal as herein illustrated, which plunger shaft 64 extends axially slidable through a correspondingly non-round or hexagonal passage 104 in the inner end bore portion of the beforementioned plunger position adjusting bushing S8. The plunger shaft 64 is thus axially slidable but nonrotatable relative to bushing 58. The plunger shaft 64 is formed adjacent its outer end with an external, annular groove 106, which receives a radially extending snap-ring 108. The snap-ring 108 serves as a stop which when moved into a position of abutment with the inner end of the plunger position adjusting bushing 58, as shown in FIGURE 2, serves to determine the maximum axially outwardly extending movement of the plunger shaft 64 and the attached plungl er head 62, relative to the plunger position adjusting bushing 58.

The plunger position `adjusting bushing 58 is provided with external threads which make threaded engagement with corresponding internal threads 112 in the beforementioned plunger positioning annular nut 56 by which the axial position of the bushing 58 may be adjusted relative to the annular nut 56. The annular nut 56 is nonrotatably fixed to the inner end of case 12 by means of the rear ange 24 which encircles an intermediate portion of the annular nut 56, with the

key tabs

26 and 28 in locking engagement with a pair of diametrically opposite, axially extending slots 103 and 104 formed therein.

A snap-ring 105 which engages an outwardly facing annular groove 107 formed around the exterior of the plunger positioning annular nut 56, serves to retain the plunger positioning annular nut 56 on the rear flange 24 by holding the inner forwardly facing annular surface portion 114 thereof in abutment with an intermediate, rearwardly facing annular shoulder 109 formed around the aforesaid plunger positioning annular nut 56. The plunger shaft 64 and thus the whole plunger assembly 54 is thereby adjustably positioned for limited axial movement relative to the case 12 and the outer surface of the retaining escutcheon plate 40.

The beforementioned plunger drive spring 60 which surrounds the plunger shaft portion 64, acts under compression between the inner end surface 111 of the plunger head portion 62 and the outwardly facing bottom 116 of an annular, spring retaining recess 118 formed in the bore of the plunger position adjusting bushing 58. Spring 60 thus constantly urges the plunger assembly 54 outwardly toward its fully extended position, which as beforementioned is determined by the abutment of snapring 108 with the inner end of the plunger position adjusting bushing 58.

As shown by way of example in FIGURE 5, when the roller 74 of the roller latch assembly is forced into latching engagement with a suitable latch detent 126, installed in a door jamb or the like member 128, the latch roller 74 and plunger assembly 54 are displaced inwardly relative to the case 12, against the force of spring 60, from the maximum extended position shown in FIGURE 2 in which the snap-ring 108 is in engagement with the inner end of the plunger position adjusting bushing 58, to a slightly retracted position as shown in FIGURE 5 in which the snap-ring 108 is moved inwardly away from such engagement with the bushing 58.

The latch roller 74 is provided, in a peripheral portion thereof, with a circumferentially extending adjustment slot 119, such slot being preferably formed with an arcuate `bottom surface to facilitate its reception of a correspondingly round ended adjusting tool which, as a matter of convenience, may be a coin or other similar disc-shaped object.

The installation and operational adjustment of the apparatus of the invention is as follows:

Assuming, for example, that the apparatus is to be installed in an edge of a door slab 120 in the manner shown in FIGURES 1, 2 and 5, a hole is drilled as shown at 122, of suicient diameter snugly to receive the case 12 and of sufficient depth to provide end clearance for the inwardly projecting portions of the plunger positioning adjusting bushing 58 and the inner end portion of the plunger shaft 64. The surface of the end of the door surround-ing the outer end of the hole 122 is then suitably recessed, as shown in 124, to receive the anchor plate 32 and the covering escutcheon plate 40 with the outer surface of the escutcheon plate 40 preferably ush with the edge surface of the door slab 120. The assembly is then inserted in the hole 122 and attached to the edge surface of the door slab 120 by means of the

beforementioned attachment screws

42 and 44.

Upon completion of the installation of the apparatus, in the manner hereinbefore described, and while the latch roller 74 is free of engagement with any latching detent means, the apparatus will have an appearance substantially shown in FIGURE 2, in which the outermost end portions of the latch roller 74 supporting

arms

66 and 68 and the latch roller 74 will extend outwardly beyond the outer surface of the edge of the door slab 120 and escutcheon plate 40 a certain maxim-um distance as determined by the axial positio-n of the plunger position adjusting bushing 58 in the plunger positioning annular nut 56, the snap-ring 8 being then held in abutment with the inner end surface of the adjusting bushing 58 by the force of spring 60. In event it is then desired to change or adjust the maximum distance the roller 74 extends outwardly beyond the surface of the door, a tool of the kind hereinbefore mentioned may [be placed in engagement with the slot 119 in the roller 74 and sufficient inward axial force applied to retract the plunger assembly 54 inwardly within the case 12, against the force of spring 60, a Suthcient distance to move the outer ends of the latch

roller supporting arms

66 and 68 inward to a position in which they clear the inner face of the escutcheon plate 40. The plunger head 62 and the associated plunger assembly 54 including the plunger shaft portion 64, will then be free for rotation about the longitudinal axis 38 by the application of sufficient torque through the adjustment tool. Such rotation of the plunger assembly 54 will cause corresponding rotation of the plunger position adjusting bushing 5S relative to the annular nut 56 which, by reason of their threaded interconnection, results in the bushing 58 being shifted axially inwardly or outwardly relative to the case 12, depending upon the direction of such adjusting rotation. Since the action of spring 60 normally maintains the snap-ring 108 in abutment with the inner end of the plunger position adjusting bushing 58, such axial shifting of the bushing 58 will correspondingly axially sh-ift the free, outwardly projecting position of the roller 74. The free position of the outer end of the plunger head 62 and the latch roller 74 carried thereby, may thus be adjusted to suit whatever conditions may be encountered as to clearance between the edge of the door slab 120 and an adjacent door jamb 128, or the like member, and to accommodate the depth and type `of detent into which the latch roller 74 is to make latching engagement.

Thus, an important feature of this invent-ion is accomplished, namely, that all necessary adjustments of the roller latch mechanism can be easily and conveniently accomplished after installation, without the usual necessity for its disassembly.

It is to be understood that the foregoing is illustrative only and that the invention is not limited thereby but may include various modifications and changes made by those skilled in the art without departing from the scope of the invention as defined by the appended claims.

We claim:

1. A latch assembly, compris-ing:

a hollow tubular case having a forward end opening and a rear end opening;

an inwardly projecting, annular, rear flange formed 0n the rear end of said case;

an outwardly projecting, annular, front ange formed on the forward end of said case;

a first plate member having a central opening encircling the forward end portion of said case, in abutment with the rearward surface of said front fiange;

a second plate member posit-ioned adjacent to and parallel with said rst plate member, in abutment With the forward surface of said front flange, said front fiange being thereby adapted to be fixedly clamped between said first and second plate members;

a plunger assembly axially reciprocably slidably contained in said tubular case, said plunger assembly having an inwardly extending plunger shaft having a first non-round cross sectional form and a forwardly extending plunger portion having a second non-round cross sectional form;

an outer opening formed in said second plate member coaxial with said tubular case and having a nonround shape conforming to said second non-round cross section, whereby said plunger is axially movable but prevented from rotation thereby when said plunger portion is in extended position through and in engagement with said outer opening;

an annular nut coaxially fixed to said rear flange, within the rear end portion of said tubular case;

an adjustment sleeve coaxially threaded through said annular nut and having a coaxial guide passage therethrough through which said plunger shaft extends and having a non-round shape conforming to said first non-round shape, whereby said adjustment sleeve and said shaft are axially slidable but nonrotatable relative to one another and whereby said sleeve is adjustable in axial position relative to said tubular case by rotation thereof relative to said annular nut, and said sleeve is rotatable relative to said annular nut by rotation of said plunger assembly;

stop means on said plunger shaft engageable with the inner end of said adjustment sleeve, limiting the outward sliding movement and determining the maximum extended position of said plunger assembly relative to said adjustment sleeve;

resilient means engaging said plunger -assembly and constantly urging said plunger -assembly in an outward direction relative to said tubular case to the limit determined :by the engagement of said stop means with said inner end of said adjustment collar;

said plunger assembly being retractable rearwardly in said tubular case, by application of axial force to said plunger assembly in opposition to said resilient means, to a retracted position in which said plunger portion is disengaged from said outer opening, there- :by freeing said plunger assembly for rotation relative to said tubular case, whereby said adjustment sleeve may be adjustably rotated.

2. Apparatus in accordance with claim 1 and a roller member rotatably carried in said plunger portion for rolling engagement with a latch detent means:

and tool engagement means included in said roller member for application of torque for rotation of said plunger assembly relative to said tubular case.

3. Apparatus in accordance with claim 2 in which said tool engagement means comprises a slot formed in the peripheral portion of said roller member.

4. A latch assembly, comprising:

a hollow tubular case having a forward end opening and a rear end opening;

lan inwardly projecting, annular, rear ange formed on the rear end of said case;

an outwardly projecting, annular, front flange formed on the forward end of said case;

a plate member having a central opening positionable coaxially with respect to the forward end portion of said case, in abutment with one of the surfaces of said front flange;

means for fixedly clamping said plate member in abutment with such surface of said front flange;

a plunger assembly axially reciprocably slidable contained in said tubular case, said plunger assembly having an inwardly extending plunger shaft having a first non-round cross sectional form and a forwardly extending plunger portion having a second nonround cross sectional form,

said central opening formed in said plate member c0- axial with said tubular case having a non-round shape cooperating with said second non-round cross section, such that said plunger is axially movable but 7 8 prevented from rotation thereby when said plunger Ward direction relative to said tubular case to the portion is in extended position through and in enlimit determined by the engagement of said stop gagement with said central opening; means with said inner end of said adjustment collar; an annular nut means coaxially fixed to said rear said plunger assembly being retractable rearwardly in ange, Within the rear end portion of said tubular said tubular case, by application 0f axial force to Case; said plunger assembly in opposition to said resilient an adjustment sleeve coaxially threadedlthrough said means, to a trac/[ed position ln which said plunger annular nut means and havmg, a Cofaxal guide Pas' portion is disengaged from said outer opening, theresage therethrough through which said plunger shaft by freeing said plunger assembly for rotation relan extends and having a non-round shape cooperating 10 with said rst non-round shape, such that said adjustment sleeve land said shaft are axially slidable but non-rotatable relative to one another and whereby References Cited said sleeve is adjustable in axial position relative to said tubular case by rotation thereof relative to said UNITED STATES PATENTS annular nut means, and said sleve is rotatable rela- 2,541,720 2/1951 Robinson 292 ..75 tive to said annular nut means by rotation of said Iplunger assembly; FOREIGN PATENTS stop means on said plunger shaft engageable with the 875,650 8/ 1961 Great Britain. inner end of said adjustment sleeve, limiting the out- 979,038 l/ 1961 Great Britain. ward sliding movement and determining the maximum extended position of said plunger assembly MARVIN A. CHAMPION, Primary Examnen relative to said adjustment sleeve;

resilient means engaging said plunger assembly and EDWARD C' ALLEN Exammer' constantly urging said plunger assembly in an out- I. R. MOSES, Assistant Examiner.

tive to said tubular case, whereby said adjustment sleeve may be adjustably rotated.

Claims

1. A LATCH ASSEMBLY, COMPRISING: A HOLLOW TUBULAR CASE HAVING A FORWARD END OPENING AND A REAR END OPENING; AN INWARDLY PROJECTING, ANNULAR, REAR FLANGE FORMED ON THE REAR END OF SAID CASE; AN OUTWARDLY PROJECTING, ANNULAR, FROMT FLANGE FORMED ON THE FORWARD END OF SAID CASE; A FIRST PLATE MEMBER HAVING A CENTRAL OPENING ENCIRCLING THE FORWARD END PORTION OF SAID CASE, IN ABUTMENT WITH THE REARWARD SURFACE OF SAID FRONT FLANGE; A SECOND PLATE MEMBER POSITIONED ADJACENT TO AND PARALLEL WITH SAID FIRST PLATE MEMBER, IN ABUTMENT WITH THE FORWARD SURFACE OF SAID FRONT FLANGE, SAID FRONT FLANGE BEING THEREBY ADAPTED TO BE FIXEDLY CLAMPED BETWEEN SAID FIRST AND SECOND PLATE MEMBERS; A PLUNGER ASSEMBLY AXIALLY RECIPROCABLY SLIDABLY CONTAINED IN SAID TUBULAR CASE, SAID PLUNGER ASSEMBLY HAVING AN INWARDLY EXTENDING PLUNGER SHAFT HAVING A FIRST NON-ROUND CROSS SECTIONAL FORM AND A FORWARDLY EXTENDING PLUNGER PORTION HAVING A SECOND NON-ROUND CROSS SECTIONAL FORM; AN OUTER OPENING FORMED IN SAID SECOND PLATE MEMBER COAXIAL WITH SAID TUBULAR CASE AND HAVING A NONROUND SHAPE CONFORMING TO SAID SECOND NON-ROUND CROSS SECTION, WHEREBY SAID PLUNGER IS AXIALLY MOVABLE BUT PREVENTED FROM ROTATION THEREBY WHEN SAID PLUNGER PORTION IS IN EXTENDED POSITION THROUGH AND IN ENGAGEMENT WITH SAID OUTER OPENING; AN ANNULAR NUT COAXIALLY FIXED TO SAID REAR FLANGE, WITHIN THE REAR END PORTION OF SAID TUBULAR CASE; AN ADJUSTMENT SLEEVE COAXIALLY THREADED THROUGH SAID ANNULAR NUT AND HAVING A COAXIAL GUIDE PASSAGE THERETHROUGH THROUGH WHICH SAID PLUNGER SHAFT EXTENDS AND HAVING A NON-ROUND SHAPE CONFORMING TO SAID FIRST NON-ROUND SHAPE, WHEREBY SAID ADJUSTMENT SLEEVE AND SAID SHAFT ARE AXIALLY SLIDABLE BUT NONROTATABLE RELATIVE TO ONE ANOTHER AND WHEREBY SAID SLEEVE IS ADJUSTABLE IN AXIAL POSITION RELATIVE TO SAID TUBULAR CASE BY ROTATION THEREOF RELATIVE TO SAID ANNULAR NUT, AND SAID SLEEVE IS ROTATABLE RELATIVE TO SAID ANNULAR NUT BY ROTATION OF SAID PLUNGER ASSEMBLY; STOP MEANS ON SAID PLUNGER SHAFT ENGAGEABLE WITH THE INNER END OF SAID ADJUSTMENT SLEEVE, LIMITING THE OUTWARD SLIDING MOVEMENT AND DETERMINING THE MAXIMUM EXTENDED POSITION OF SAID PLUNGER ASSEMBLY RELATIVE TO SAID ADJUSTMENT SLEEVE; RESILIENT MEANS ENGAGING SAID PLUNGER ASSEMBLY AND CONSTANTLY URGING SAID PLUNGER ASSEMBLY IN AN OUTWARD DIRECTION RELATIVE TO SAID TUBULAR CASE TO THE LIMIT DETERMINED BY THE ENGAGEMENT OF SAID STOP MEANS WITH SAID INNER END OF SAID ADJUSTMENT COLLAR; SAID PLUNGER ASSEMBLY BEING RETRACTABLE REARWARDLY IN SAID TUBULAR CASE, BY APPLICATION OF AXIAL FORCE TO SAID PLUNGER ASSEMBLY IN OPPOSITION TO SAID RESILIENT MEANS, TO A RETRACTED POSITION IN WHICH SAID PLUNGER PORTION IS DISENGAGED FROM SAID OUTER OPENING, THEREBY FREEING SAID PLUNGER ASSEMBLY FOR ROTATION RELATIVE TO SAID TUBULAR CASE, WHEREBY SAID ADJUSTMENT SLEEVE MAY BE ADJUSTABLY ROTATED.