US3837690A

US3837690A - Information storage articles employing resilient locking sleeves

Info

Publication number: US3837690A
Application number: US00386234A
Authority: US
Inventors: H Fraser; R Larson; H Rinkleib
Original assignee: International Business Machines Corp
Current assignee: International Business Machines Corp
Priority date: 1973-08-06
Filing date: 1973-08-06
Publication date: 1974-09-24
Anticipated expiration: 1991-09-24
Also published as: FI59889B; GB1420040A; JPS5333056B2; CA1028307A; ES223365U; SE7409219L; BE816913A; FI234174A; FR2240487A1; DE2434847C3; CH572652A5; AU6856974A; ZA743616B; NO742793L; NO143360B; NO143360C; JPS5040105A; DK416174A; NL170991B; FI59889C

Abstract

A tape spool and cover are latched together by a tubular sleeve arrangement. A hollow core tape spool has an inner frustroconical camming surface adjacent an axially outwardly facing shoulder. A releasable latch includes a unitary resilient sleeve inserted into the hollow core and is cammed radially inwardly for creating radial outward forces on the opposite sleeve end outside the spool. A first axial end portion of the sleeve has a first type locking resilient finger extending out of the hollow core and a second type resilient finger in locking engagement with the hollow core tape spool. A radially inwardly extending annular rib divides the first and second axial end portions to provide a bending moment transfer ring. The slots defining the axially extending fingers extend to and preferably into the rib for providing a moment bridge for transferring the radial inward compression on the second axial end portion to a radially outwardly exerting force in the first axial end portion. It is preferred that such slots terminate on or near a common circumferential line extending around the sleeve. The outer end portion of the first type of fingers includes a latching shoulder, plus a camming surface for enabling radial inward camming all first type fingers for enabling releasable engagement between the tape spool and a cylindrical cover.

Description

United States Patent [1 1 Fraser, J r. et al.

[ Sept. 24, 1974 INFORMATION STORAGE ARTICLES EMPLOYING RESILIENT LOCKING SLEEVES [75] Inventors: Harvey R. Fraser, Jr.; Richard T.

Larson, both of Boulder; Helfried O. Rinkleib, Longmont, all of C010.

[73] Assignee: International Business Machines Corporation, Armonk, N.Y.

[22] Filed: Aug. 6, 1973 [21] Appl. No.: 386,234

[52] US. Cl 285/319, 242/685, 279/49 [51] Int. Cl. F161 39/00 [58] Field of Search 285/319, 315, 322, 39;

Primary ExaminerJordan Franklin Assistant Examiner-Peter Nerbun Attorney, Agent, or Firm-Herbert F. Somermeyer [5 7] ABSTRACT A tape spool and cover are latched together by a tubu lar sleeve arrangement. A hollow core tape spool has an inner frustro-conical camming surface adjacent an axially outwardly facing shoulder. A releasable latch includes a unitary resilient sleeve inserted into the hollow core and is cammed radially inwardly for creating radial outward forces on the opposite sleeve end outside the spool. A first axial end portion of the sleeve has a first type locking resilient finger extending out of the hollow core and a second type resilient finger in locking engagement with the hollow core tape spool. A radially inwardly extending annular rib divides the first and second axial end portions to provide a bending moment transfer ring. The slots defining the axially extending fingers extend to and preferably into the rib for providing a moment bridge for transferring the radial inward compression on the second axial end portion to a radially outwardly exerting force in the first axial end portion. It is preferred that such slots terminate on or near a common circumferential line extending around the sleeve. The outer end portion of the first type of fingers includes a latching shoulder, plus a camming surface for enabling radial inward camming all first type fingers for enabling releasable engagement between the tape spool and a cylindrical COVCI'.

19 Claims, 7 Drawing Figures Ila PAIEMEMEPMM 3,83%690 INFORMATION STORAGE ARTICLES EMPLOYING RESILIENT LOCKING SLEEVES BACKGROUND OF THE INVENTION The present invention relates to insertable locking mechanisms, particularly of the tubular type, for use with hollow core articles.

Spools for supporting magnetic media spirally wound thereon have employed various mechanisms for attaching the spool to rotatable supports and/or dust covers. Since such spools should be low cost, any such locking mechanisms should have a corresponding low cost. Further, if the mechanism is manufactured separately of the spool, the assembly of the two parts should be extremely simple and low cost.

Some tape-containing spools are usable with automatic apparatus. Such automatic apparatus automatically engages and disengages the locking mechanisms on the spool. Because of desired low cost, it is highly desirable that such locking mechanisms be manufactured using plastic molding processes employing known resilient plastic materials. Also, because of the contamination problem of magnetic tape causing dropouts and the like, the locking mechanisms should be carefully designed to avoid wear. That is, when the locking mechanism engages automatic apparatus for spool support opening or closure, reducing wear minimizes the amount of debris generated during each attachment or closure. This, in turn, reduces the exposure for magnetic recording errors caused by such debris being generated in the immediate vicinity of a recording medium.

Further, many automatic apparatus require for avoiding tape position errors during spool rotation the spool to be precisely centered; accordingly, any locking mechanism should be self-centering not only on the spool, but also in the locking engagement portion. This centering is important for reducing vibrations when the spool is being rotated at high rotational velocities. The force required to engage and disengage the locking mechanism should be carefuily controllable. Such forces should be chosen to be sufficient to minimize the amount of power required, but should be sufficiently strong to ensure that the spool of tape is always affixed to either the closure or the attached apparatus in a secure manner. These camming forces are affected by wear and tolerances of manufacture.

An example of an information media storing article with which the present invention may be successfully employed is shown in the commonly assigned copending patent application, Ser. No. 318,954, filed Dec. 27, 1972.

SUMMARY OF THE INVENTION A sleeve-type insert constructed in accordance with the present invention and being particularly adaptable for insertion into a hollow core member, such as the hollow core of a tape spool, consists of a unitary cylindrical body having first and second axial end portions and consisting of resilient material. The sleeve preferably, but not necessarily, includes an annular radially inwardly extending rib separating the first and second axial end portions. Each axial end portion has a plurality of slots extending axially approximately from the area of the rib to the respective axial ends such that each axial end portion consists of a plurality of axially extending integrally formed resilient fingers. The slots in the first and second axial end portions are circumferentially displaced such that a stress transferring bridges in the area of the rib extends between fingers in the opposite axial end portions.

In a preferred form of the invention, afirst axial end portion includes a plurality of locking fingers each having a radially extending shoulder at the outward end portion, which also is the axial end of the first axial end portion. Additionally, a second type of axially extending fingers, shorter than the first type, is disposed intermediate two of said first type of fingers. The second type of finger has a radially extending latch detent for insertion into a receptacle portion of the hollow core member into which the sleeve is inserted. It is preferred that the outer end portions of the first type of fingers in the first axial end portion have all the same dimensions. Hence, each two first type fingers bracketing a second type finger extend circumferentially around the outer axial end of the second type of fingers.

The second axial end portion has a plurality of slots ending at the rib portion immediately adjacent the first type of fingers. It is preferred that such second axial end portion slots be centrally located between adjacent slots bordering each of the first type of fingers. In one form of the invention, the slots defining each second type of finger end adjacent a broad circumferential finger of the second axial end portion. In another version of the invention, there is an additional slot extending toward the rib end portion of the second type of first axial end portion fingers.

In the most preferred form of the invention, the slots in the first and second axial end portions both terminate approximately along a common plane transverse to the axis of the sleeve. Hence, the termination of each slot is on a circumferential line somewhere in the area of the rib. Overlapping or underlapping the slots varies stress concentrations, preloading displacements, and load or stress transfers.

The invention also contemplates the combination of the above-described sleeve inserted into a special receptacle formed in the hollow core member, preferably the core member of a magnetic tape spool. Such core member has an open axial end having a first cylindrical end portion. At the inner end of the cylindrical end portion is an annular shoulder facing such open axial end. At the radial inner end of the axial facing shoulder is a frustro-conical cam. The inside diameter of the frustro-conical cam begins with a diameter greater than the outside diameter of the second axial end portion and recedes in a direction away from the open axial end to a diameter substantially smaller than the outside diameter of the sleeve. The sleeve, inserted with the second axial end portion, is radially compressed by the frustro-conical cam. Additionally, the hollow core member has a plurality of detents for receiving the detent members on the axial end portions of the second type of fingers. The sleeve is inserted until those detents are latched in such receptacles. The sleeve is firmly held in the hollow core member by the resilient urging of the second type of fingers by the radial compression of the second axial end portion. The first type of fingers extends axially outwardly beyond the first axial end portion of the hollow core member for receiving a cover and latching same to the spool. Such first type fingers are radially inwardly urgeable against the force transmitted thereto by the fingers of the second axial end portion.

The arcuate surfaces of the axial end portion of the first type of fingers have a radius of curvature in accordance with a minimum of radius of the first axial end portion when being cammed radially inwardly for latching or unlatching action. This arrangement reduces wear. It is preferred that the radial extension on both the first and second types of fingers in the first axial end portion be outward.

When inserted into the hollow core member, the sleeve insert rib portion is suspended in a free space between the axially facing shoulder and the engagement of the second type of fingers with the detent receptacles. This arrangement facilitates transfer of forces in a symmetrical manner to all of the first type of fingers which facilitates the use of a cylindrical tool for simultaneously and equally radially inwardly urging all of the first type fingers away from engagement with the inner diameter of the hollow core member thereby releasing a cover or sleeve latched to the hollow core member. A spool support member may also be engaged to the spool through the use of the radial shoulders on the axial end portions of the first type of fingers.

The foregoing and other objects, features, and advantages of the invention will be apparent from the following more particular description of the preferred embodiments of the invention, as illustrated in the accompanying drawing.

The Drawing FIG. 1 is a diagrammatic sectional view of a stressed sleeve in one axial end portion of a hollow core member.

FIG. 2 is a perspective view of the stressable sleeve of the present invention.

FIG. 3 is an exploded simplified perspective view, partially in section, of a spool storage cartridge employing the present invention.

FIG. 4 is an enlarged and simplified fragmentary central cross-sectional diagrammatic view of a cartridge illustrating one aspect of the locking mechanism for the FIG. 2 illustrated cartridge in a closed and locked relationship. The sleeve is not separately shown.

FIG. 5 is a simplified enlarged fragmentary crosssectional diagrammatic view, similar to FIG. 4, showing a cartridge supported via a stressed sleeve.

FIG. 6 is a simplified enlarged fragmentary crosssectional diagrammatic view similar to FIG. 4 of a cartridge being opened.

FIG. 7 is a simplified partial diagrammatic showing of an improved end configuration for locking fingers on a sleeve insert.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now more particularly to the drawing, like numerals indicate like parts and structural features in the various views and diagrams. Sleeve 10 is insertable into hollow core member 44 via open axial end 48. Hollow core member 44 includes a hollow cylindrical axial end portion 11 with an inside diameter substantially greater than the outside diameter of cylindrical sleeve 10. At the axial inner end of axial end portion 11 is annular outward axial facing truncated conical annular shoulder 12. Axially inward of annular shoulder 12 is frustro-conical tapered ramp or cam 13. Ramp 13 centers insert 10 inside hollow core member 44 and simultaneously exerts radial inward forces on all fingers 14 of the second axial end portion of sleeve 10. This radial inward moment is transferred via central stress transferring section 15 to a set of axially outwardly extending locking fingers 52. The transmitted forces result in fingers 52 being radially outwardly urged against the inner diameter of hollow core member 44 at its one axial end 48. Additionally, the same forces generated on fingers 14 are transmitted through central section or rib 15 to a plurality of sleeve retaining axially extending fingers (second type) 17. Each finger 17 has a radially outwardly extending detent l9 engageable into detent receptacle or aperture 20 in axial end portion 11 of hollow core member 44. Detents 19 firmly retain sleeve 10 inside hollow core member 44.

Each of the locking fingers 52 extends axially outwardly beyond open end 48. Each finger has a radially outwardly extending locking shoulder 64 spaced from axial end 48 for receiving a tubular cover 26, later described, for locking same to the spool, which includes core member 44. Cover 26 includes a camming surface which engages camming surface 62 of axial outer end portion 152 urging all of the locking fingers 52 simultaneously and symmetrically radially inward, such that the camming surface on the cover slides over surface 62 and then engages locking shoulder 64. Fingers 52 return to the radial outward position for latching the cover securely to the spool member.

To reduce wear, it is desirable that the tubular cover 26 move over the spool in a truly concentric manner. To this end, all of the outward portions 152 of locking fingers 52 are identically formed; i.e., they have the same circumferential extent. To achieve this result, the two locking

fingers

52a and 52b bracketing a second type finger 17 have a circumferentially reduced portion adjacent the second type fingers 17. Beyond the outer axial extent of each finger 17, as at detent 19,

fingers

52a and 52b have a circumferentially enlarged portion to achieve the above-stated results. In a preferred form of the invention, all of fingers 52 are constructed as shown for

fingers

52a and 52b bracketing a second type finger 17. In one constructed version of the invention, four sets of

fingers

52a, 52b and second type fingers 17 constituted the first axial end portion of a sleeve.

Second axial end portion, including fingers 14, in one constructed embodiment, had fingers of different circumferential extents. First fingers 14a circumferentially bracket elongated

slots

23 and 24 between two adjacent first type .or locking fingers 52. The second axial end portion also has circumferentially enlarged fingers 14b with a circumferential extent bracketing second type finger 17 of the first axial end portion and the two adjacent slots 25. The radial inward compression of fingers 14b not only radially outwardly urge fingers 17, respectively, but also assist in the radial out ward urging of

fingers

52a and 52b, respectively. Because of differing circumferential extents between fingers 14a and 14b, it is important that the different size fingers be symmetrically disposed about the sleeve. Additionally, a slot may be provided within finger 14b as indicated by dotted line 27, which slot may have an axial extent less than the other slots within the second axial end portion. Other configurations can readily be envisioned, including some alternatives discussed later.

The annular rib 15 can have an axial extent as shown by dotted lines 29 in FIG. 2. The slots in both the first and second axial end portions extend into the rib portion up to a common circumferential line 30 axially centrally of rib 15. This arrangement provides for good bending moment transfer between the two axial end portions. By making a slot shorter, the bending moment is reduced; that is, if the slot did not terminate in approximate vicinity of rib 15, the radial inward urging of fingers 14 in the second axial end portion would not be fully transmitted to the fingers in the first axial end portion. That is, the radial outward urging of locking fingers 52 would be reduced by shortening the slots. Accordingly, for maximum controlled force transfer, the slots in the first and second axial end portions should terminate in the proximate vicinity of common circumferential line 30, which defines a common plane transverse to the axis of sleeve 10. It is permissible within the invention to underlap the slots to the outer axial perimeter of rib 15 such as identified by lines 29 in FIG. 2.

It should also be noted that the circumferential extent of

fingers

14, 52, and 17 is much greater than the circumferential extent of the slots. This is a design choice to provide maximum forces being transferred from the radial inward urging of fingers 14 to the

fingers

17 and 52 in the first axial end portion.

In a constructed embodiment of the invention, the axial length of fingers 14 is approximately one-half of the axial length of fingers 52. This means that the radial inward force exerted on fingers 14 by frustro-conical camming surface 13 is approximately twice as great as the radial outward urging of fingers 52 at the actual outward end portions 152. Also, fingers 17 in the first axial end portion are somewhat shorter than looking fingers 52. The result is that the radial outward urging, i.e., the locking force, on detents 19 is substantially greater than the locking force exerted on locking fingers 52. In such constructed embodiment, locking fingers 17 have a somewhat greater axial length than second axial end portion fingers 14, the actuating fingers in the radial force locking engagement provided in the first axial end portion. This arrangement is a best mode of practicing the invention. Keeping the force on detents 19 greater than on locking fingers 52 ensures that sleeve stays secured to the hollow core even when fingers 52 are moved radially inwardly, as later described.

The internal surface features of hollow core member 44 cooperate with the geometric configuration of sleeve 10 to provide optimum controlled transfer of the radial inward forces on fingers 14 to radial outward forces on locking fingers 52. The axial end cylindrical portion 1 1 has an inside diameter greater than the outside diameter of sleeve 10. This permits sleeve 10 to be suspended in free space inside this portion. Axially outwardly facing shoulder 12 reduces the inside diameter of hollow core member 44 to a diameter less than the outside diameter of sleeve 10. Then, frustro-conical surface 13 further reduces the inside diameter for ex erting radial inward forces on fingers as sleeve 10 is inserted into member 44. The axial lengths of fingers l4 and 52 are selected such that annular rib 15 is disposed in the free space within axial cylindrical end portion 11 just axially outward of shoulder 12. Rib 15 and the finger portion in juxtaposition thereto are in free space permitting free movement of the sleeve in this area for efficiently transferring radial forces from fingers 14 to fingers 52. The annular space between sleeve 10 and portion 11 in the vicinity of rib l5 permits uninhibited movements for enabling the abovementioned efficient transfer of forces. Rib 15 is an annular fulcrum for the transfer of the radial forces. Without rib l5, stress concentrations in the area where the fingers join about common line 30 could cause fractures with resultant decreased efficiency of energy transfer between the radially urged fingers.

The combination of hollow core member 44 and sleeve 10 is best used in connection with a tapecontaining cartridge 16 shown in FIG. 3. A tubular cover 26 is releasably locked to core member 44 via locking fingers 52 locking shoulders 64. In this regard, in cartridge 16, tubular cover 26 axially slides over core 44 to engage radially enlarged base or spool flange 46 of single-flanged spool 28. Cover 26 has open end 32 and a tapered and partially closed end 34. Tapered end 34 provides ease of entry and centering in a storage compartment (not shown). Cover flange 36 partially closes end 34 and has locking shoulder 38 for sealing engagement with base 28 via resilient washer 40. Cover portion 42 adjacent open end 32 is tapered at the inner surface to a reduced thickness.

Base 28 is a single flange spool including cylindrical hub or core portion 44 with spool flange 46 fixed to the hub at one end. End 48 of hub 44 opposed to flange 46 is hollow for receiving sleeve 10 having resilient locking fingers 52. The hub is designed to carry a flexible wound web 54, shown in phantom, for example, in the fonn of magnetic tape, on the hub surface bounded by spool flange 46 and resilient fingers 52. The face of spool flange 46 opposed to hub 44 includes a clutch surface in the form of serrations 56 circumferentially spaced around magnetically permeable disk 22. Deformable skirt 58 extends at an angle from the periphery of spool flange 46 away from hub 44.

When cover 26 and base 28 are brought together, hub 44 and web 54 extend into and are surrounded by the open tubular portion of cover 26. As closure is continued, cam surfaces 62 of resilient fingers 52 come into contact with annular cover flange 36. This action flexes fingers 52 inwardly to pass into and through the central opening in cover flange 36 past washer 40 to locking shoulder 38. When closure is completed, cam portion 62 of each resilient finger 52 extends past annular flange 36, so that the lateral inward constraint of annular flange 36 is no longer applied to resilient fingers 52. In this unconstrained condition, resilient fingers 52 straighten; and locking teeth 64 bear axially against locking shoulder 38, see FIG. 4. With locking shoulder 38 and resilient locking fingers 52 locked together, base 28 is secured within tubular cover 26. With closure of the cartridge completed, resilient washer 40 contacts an adjacent edge of wound web 54 to retard the web from unwinding inside cartridge 16.

Referring again to FIG. 4, a segment of the cartridge with cover 26 and spool 28 locked together is diagrammatically shown in simplified cross-section. For simplicity, in FIGS. 4 and 6, sleeve 10 is shown as an integral part of hollow spool core 44, it being understood the arrangement of FIGS. 1 and 2 is used in apparatus shown in these figures.

Fingers 52 remain in locking contact with shoulder 38 until urged radially inwardly. The resiliency and dimensions of the fingers is such that an axial force exerted between the cover and base member will not normally release the fingers 52 from locking shoulder 38. Similarly, the number, array, resiliency, and dimensions of the fingers also normally prevent manual release of the fingers from the shoulder. Fingers 56 are arrayed in such a manner and are of such stiffness that in the absence of tool 74 (FIG. 6) they cannot normally all be depressed simultaneously manually without great difficulty. As long as one finger remains in locking contact with shoulder 38, separation of the base and cover members is not possible. Cover 26 completely encloses base 28 such that no portion of the base can be readily grasped to remove the cover.

When base 28 and cover 26 are in closed relationship, tapered end wall cover portion 42 frictionally engages deformable skirt 58 of spool flange 46. In a preferred embodiment, the angle of skirt 58 and the angle of tapered wall portion 42 are such that contact between the two elements is made quickly during closure; and the seal is tight and substantially dust proof.

FIG. 4 also shows an annular groove 66 on the inner surface of fingers 52. This radially inwardly opening groove provides for releasable latching for engagement with detent 12 for retaining the cartridge during storage or conveyance. The right side of FIG. shows, in phantom, the details of one form of detent 12. A number of resilient detent fingers 68 each have a beaded tip 72 for camming engagement and disengagement with groove 66 in resilient fingers 52, as shown. Relative axial movement between cartridge 16 and detent 12 cams detent fingers 68 inwardly until the beaded tips 72 on fingers 68 seat in groove 66 to secure the cartridge. Cartridge 16 is disengaged from detent 12 by pulling them apart with a force exceeding the resiliency of detent fingers 68.

To remove cover 26 from base 28, as shown in FIG. 6, tool 74 has annular cam follower 76 to mate annularly disposed cam surfaces 62 on fingers 52 simultaneously upon movement of tool 74 towards the cartridge. Each cam surface 62 rides on the surface of cam follower 76 to inwardly urge fingers past shoulder 38 for releasing cover 26. As shown in FIG. 6, fingers 52 are in an unlocking relation to shoulder 38, and separation of the base and cover members is being initiated by the continuing axial movement of the tool to push spool 44 from cover 26.

In inserting and removing tubular cover 26 from the tape spool, the sliding engagement of the cams on the cam surfaces of the tubular cover, such as washer 40 of FIG. 4, may cause wear on the cammed surfaces. Such wear may generate particulate matter, which can contaminate recording media on the spool. That is, such minute debris on a recording media can cause signal dropout and, hence, recording errors. Therefore, it is extremely important that wear be reduced on camming surface 62 for reducing such debris. This is accomplished by adjusting the radius of curvature of camming surface 62 to that radius of the maximum radial inward deflection of locking fingers 52 rather than establishing a radius of curvature for surface 62 that is equal to the radial outward radius of sleeve 10. In FIG. 7, two fingers 52 are shown in the radial outward position with the solid lines 79 representing the radius of curvature of sleeve from its central axis 80. This is the maximum radius of curvature. The radius of curvature of the inner annular camming surface on tubular cover 26 corresponds to the maximum inward deflection of fingers 52 as from axis 81, which is substantially less than the maximum radius of curvature. This arcuate cam surface, represented by dotted line 82 engages surface 62 only at the

circumferential extremities

83 and 84 of all fingers 52. The circumferential central portion 85 of fingers 52 initially is not engaged with the inner annular camming surface of tubular cover 26. As a result, maximum forces are exerted at 83 and 84, resulting in increased wear. Such increased wear on camming surface 62 is alleviated by adjusting the radius of curvature of camming surface 62 to that of dotted line 82 such that the annular inner facing camming surface of tubular cover 26 engages substantially all, if not all, the camming surface 62 of all fingers 52. This substantial contiguous engagement across the circumferential extent of all surfaces 62 continues throughout the radial movements of axially outer end portions 152 thereby minimizing wear by reducing forces to a minimum across the camming surfaces. In FIG. 7, the radial inward position of the two fingers 52 is indicated by dotted lines 86.. It should be noted that

dotted lines

82 and 86 have arcuate portions which are concentric about

axes

81 and 80, respectively.

Choice of materials for the base, cover, and locking mechanism of the cartridge and detent may be such as to avoid wear and generation of debris within the cartridge and the storage apparatus. The various parts are constructed either of wear resistant resilient metals or plastics which do not deteriorate or generate particles upon contact and which provide sufficient stiffness to avoid manual unlocking of the cartridge. More importantly, it tends to minimize degradation (creep and fatique) with time. The choice of such materials is within the skill of the art. It is preferred that sleeve 10 be molded from an acetal resin (polyacetal), such as DELRIN or CELCON materials, no limitation thereto intended.

It must also be understood that the preferred embodiments set forth hereinabove may be easily modified while leaving the resulting mechanism within the scope of the subject invention. For example, reversal of the parts in the locking mechanism from the cover member to the base member may be readily achieved. Short locking fingers with longer second type fingers may also be employed. In another variation, detents 19 may be on locking fingers 52, the radial movements of such fingers being such that a detent l9 always remains latched as shown in FIG. 1. One locking finger 52 per one detenting finger 17 may also be employed. From the above discussion, is is apparent that a myriad of slot-finger selections are usable to practice the present invention, no limitation to the illustrated or described configurations intended.

A secondary embodiment allows tha slots to be axially aligned. While the preferred illustrated embodiment has better force transfer characteristics, slot and finger axial alignment permits more facile variable stress finger loading. For example, ramp or cam 13 can be axially slotted for receiving some of the fingers 14 in slots to transfer less force to fingers 52 (now aligned with some of the fingers 14) with other fingers 14 providing stronger holding forces on fingers 17. Even with offset slotting, cam 13 may have an undulating surface for

variable loading fingers

52 and 17.

While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and detail may be made therein without departing from the spirit and scope of the invention.

What is claimed is: 1. A sleeve for insertion into a hollow core member having a plurality of circumferentially displaced, radially inwardly opening latch receptacles adjacent one end, a radially inwardly extending annular shoulder disposed axially inward of said receptacles from said one end and inside the core, and an annular camming surface disposed axially inward of said annular shoulder from said one end;

the improved sleeve comprising: a unitary tubular body having first and second axial end portions and consisting of resilient material;

an annular rib separating said first and second axial end portions and extending radially inwardly from both said axial end portions;

each axial end portion having a plurality of slots axially extending proximately from said rib to the respective ends such that each said axial end portions consists of a plurality of axially extending resilient fingers;

said slots in said first axial end portion being circumferentially displaced from slots in said second axial end portion; and

said fingers being of greater circumferential extent than said slots, and the sleeve having an outside diameter greater than an inside diameter of the annular camming surface.

2. The sleeve set forth in claim 1 further including in combination:

said first axial end portion having first and second types of fingers;

said first type of fingers being locking fingers and extending proximately from said rib to an end of said first axial end portion and including radially extending shoulder means adjacent said first axial end;

said second type of finger being interspersed between said first type of fingers and extending axially only partially toward said first axial end and including a radially extending detent; and

said second type of finger being symmetrically disposed circumferentially about said sleeve.

3. The sleeve set forth in claim 2 wherein each said finger of the first type having an outward end portion including said radially extending shoulder of circumferentially equal dimensions and disposed about said sleeve such that said first type fingers immediately adjacent said second type fingers having a smaller circumferential extent from said detent on said first type finger to proximately along said rib and including a greater circumferential extent axially outward of said detent means on said second type finger.

4. The sleeve set forth in claim 3 wherein said resilient fingers in said second axial end portion being disposed alternately with said fingers of the first type and including a finger having a circumferential extent greater than said fingers of the second type whereby slots in the first axial end portion adjacent said finger of the second type being opposite a same finger, respectively, in the second axial end portion extending between the immediately abutting first type fingers.

5. The sleeve set forth in claim 3 wherein said second axial end portion includes slots extending to proximately said rib immediate said first type fingers and including shorter axially extending slots circumferentially aligned with said second type fingers and being further from said rib than said first type finger circumferentially aligned slots.

6. The sleeve set forth in claim 1 wherein all of said slots extend into said rib and effectively terminate substantially on the same circumference of said sleeve whereby a bending moment action between the first and second axial end portions is established via said rib.

7. The sleeve set forth in claim 6 wherein said rib includes a radially inwardly extending continuous circur'nferentially enlarged portion.

8. The sleeve set forth in claim 6 wherein said second axial end portion is shorter than said first axial end portion;

said first axial end portion having first and second type fingers, said first type of fingers extending axially to the entire length of said first axial end portion and said second type of fingers extending only partially the length of said first axial end portion;

said second type fingers being symmetrically disposed circumferentially about said sleeve and including radially extending detents at the outer end portions;

said first type fingers having radially outwardly extending shoulders at their outer end portions, each circumferential extent of said first type fingers at the outer end portion being identical such that said first type fingers adjacent said second type fingers including a portion extending axially outward of said detent means; and

said first type fingers further including a camming surface extending from said radial shoulder outward end to the radial inward side of said first type fingers for forming a camming surface for enabling urging said first type fingers radially inward for closing the slots adjacent said outward end portions of said first type fingers.

9. The sleeve set forth in claim 8 wherein there are twice as many first type fingers as second type fingers, and said second axial end portion slots being circumferentially aligned between slots on adjacent sides of each of said first type fingers with no slots being circumferentially aligned with said second type fingers such that fingers in said second portion being of different circumferential extent with the ones adjacent said second type fingers being of greater circumferential extent than others of said fingers in said second axial end portion.

10. The sleeve set forth in claim 9 wherein said second type fingers of said first axial end portion having radially outwardly extending detents at the respective outermost axial end portion thereof; and

said outer end portions of said first type fingers having a radius on said camming surfaces circumferentially of said sleeve less than the radius of said sleeve when in its radially expanded position.

11. The sleeve set forth in claim 1 wherein said slots from both of said axial end portions extend into said rib to terminate on different circumferences of said sleeve whereby the bending moment between the first and second axial end portions is decreased as measured when terminating said slots on the same circumferential or common line.

12. The sleeve set forth in claim 11 wherein said rib includes a continuous circumferentially extending enlarged portion which extends radially inwardly.

13. The sleeve set forth in claim 1 wherein slots in said second end portions terminate short of but in juxtaposition to said rib, while the slots in said first end portion terminate axially inside said rib, and said first axial end portion having a greater axial extent than said second axial end portion, and said fingers in said first end portion each including a radially extending portion for locking engagement with another member; and

a first group of said first portion fingers having said radially extending shoulders at the axial outer end of said first portion, while others of said fingers have said radially extending shoulders intermediate said first radially extending shoulders and said rib.

14. The sleeve set forth in claim 1 further including a radially outwardly extending detent means and radially outwardly extending latching means on said fingers in one of said axial end portions.

15. A sleeve for insertion into a hollow core member and having a plurality of circumferentially displaced, radially inwardly opening latch receptacles adjacent one end, a radially inwardly extending annular shoulder axially inward of said receptacles with respect to said one end and inside the core, and an annular camming surface axially inwardly of said annular shoulder,

the improved sleeve comprising:

a unitary cylindrical body having first and second axial end portions and consisting of resilient molded plastic type material;

an axially central annular portion separating said first and second axial end portions;

each axial end portion having a plurality of slots axially extending from said annular portion to the respective ends such that each said axial end portion consists of a plurality of axially extending resilient fingers;

said first axial end portion having a greater axial extent than said second axial end portion;

said axially extending fingers in said first axial end portion being of first and second types, a plurality of fingers of each said type, said second type fingers having a radially outward extending locking portion at the axial outward extremity of said first axial end portion, said second type finger having a radially outwardly extending detent portion axially intermediate said annular portion and said locking portions; and

at least one first type finger being circumferentially interposed between any two of said second type fingers.

16. A sleeve for insertion into a hollow core member and having a plurality of circumferentially displaced, radially inwardly opening latch receptacles adjacent one end, a radially inwardly extending annular shoulder axially inward of said receptacles with respect to said one end and inside the core, and an annular camming surface axially inwardly of said annular shoulder,

the improved sleeve comprising:

a unitary cylindrical body having first and second axial end portions and consisting of resilient material;

each axial end portion having a plurality of slots axially extending from the respective ends substantially to a common circumferential line about said sleeve such that each said axial end portion consists of a plurality of extending resilient fingers axially extending from said common circumferential lines;

said slots in said first axial end portion being circum' ferentially displaced from slots in said second axial end portion; and

said first axial end portion having some fingers longer than others with each said other fingers being circumferentially interposed between two of said some fingers, each said fingers having radially extending detent portions at their respective axial outer end portions.

17. A releasable latching assembly for selective releasable engagement with an annular latch,

the improvement including in combination:

a body member to be latched having an axis of latching and a concentric cylindrical cavity;

a first portion of said cavity having a first inside diameter and including latch receptacles symmetrically disposed about the cavity;

an axially outwardly facing shoulder at the inner end of said cylindrical cavity and a frustro-conical surface extending axially inward concentric with said axis from said outwardly axially facing shoulder;

a resilient tubular sleeve disposed in said cavity and having first and second axial end portions;

an axially central annular portion separating said first and second axial end portions and disposed in said cylindrical cavity intermediate said axially facing shoulder and said locking means;

said sleeve having an outside diameter less than the inside diameter of said cylindrical portion, but an outside diameter greater than the inside diameters of said frustro-conical section;

each axial end portion of said sleeve having a plurality of slots axially extending from said central annular portion to the respective ends of said sleeve, such that each said axial end portion consists of a plurality of axially extending resilient fingers;

said slots in said first axial end portion being circumferentially displaced from said slots in said second axial end portion;

said frustro-conical surface radially inwardly urging fingers in said second axial end portion whereby fingers in said first axial end portion are radially outwardly urged with the central portion of said sleeve being free to move within said first cylindrical cavity;

said axially extending fingers in said first axial end portion being of first and second types, a plurality of such fingers of each said type, said second type fingers having a radially outwardly extending locking portion extending respectively into said receptacles in said surface of said cylindrical cavity and being symmetrically disposed circumferentially of said sleeve, each said first type of fingers extending outwardly of said cylindrical cavity and including a radial outwardly extending locking shoulder substantially parallel to a surface of said member to be latched immediately adjacent and circumferentially disposed with respect to said cylindrical cavity;

the arrangement being such that the radial inward urging on said fingers in said second axial fingers urges the fingers in said first axial end portion radially outwardly in a symmetrical uniform manner.

18. The assembly set forth in claim 17 wherein said central annular portion includes a continuously circumferentially extending radially inwardly extending enlarged portion.

19. A releasable latching assembly for selective releasable engagement with an annular latch,

the improvement including in combination:

a first portion of said cavity having a first inside diameter and including latch receptacle means symmetrically disposed about said cavity;

an axially outwardly facing shoulder at the inner end of said cylindrical cavity and a frustro-conical surface extending axially inward from said outwardly axially facing shoulder and concentric with said axis;

Claims

1. A sleeve for insertion into a hollow core member having a plurality of circumferentially displaced, radially inwardly opening latch receptacles adjacent one end, a radially inwardly extending annular shoulder disposed axially inward of said receptacles from said one end and inside the core, and an annular camming surface disposed axially inward of said annular shoulder from said one end; the improved sleeve comprising: a unitary tubular body having first and second axial end portions and consisting of resilient material; an annular rib separating said first and second axial end portions and extending radially inwardly from both said axial end portions; each axial end portion having a plurality of slots axially extending proximately from said rib to the respective ends such that each said axial end portions consists of a plurality of axially extending resilient fingers; said slots in said first axial end portion being circumferentially displaced from slots in said second axial end portion; and said fingers being of greater circumferential extent than said slots, and the sleeve having an outside diameter greater than an inside diameter of the annular camming surface.

2. The sleeve set forth in claim 1 further including in combination: said first axial end portion having first and second types of fingers; said first type of fingers being locking fingers and extending proximately from said rib to an end of said first axial end portion and including radially extending shoulder means adjacent said first axial end; said second type of finger being interspersed between said first type of fingers and extending axially only partially toward said first axial end and including a radially extending detent; and said second type of finger being symmetrically disposed circumferentially about said sleeve.

7. The sleeve set forth in claim 6 wherein said rib includes a radially inwardly extending continuous circumferentially enlarged portion.

8. The sleeve set forth in claim 6 wherein said second axial end portion is shorter than said first axial end portion; said first axial end portion having first and second type fingers, said first type of fingers extending axially to the entire length of said first axial end portion and said second type of fingers extending only partially the length of said first axial end portion; said second type fingers being symmetrically disposed circumferentially about said sleeve and including radially extending detents at the outer end portions; said first type fingers having radially outwardly extending shoulders at their outer end portions, each circumferential extent of said first type fingers at the outer end portion being identical such that said first type fingers adjacent said second type fingers including a portion extending axially outward of said detent means; and said first type fingers further including a camming surface extending from said radial shoulder outward end to the radial inward side of said first type fingers for forming a camming surface for enabling urging said first type fingers radially inward for closing the slots adjacent said outward end portions of said first type fingers.

10. The sleeve set forth in claim 9 wherein said second type fingers of said first axial end portion having radially outwardly extending detents at the respective outermost axial end portion thereof; and said outer end portions of said first type fingers having a radius on said camming surfaces circumferentially of said sleeve less than the radius of said sleeve when in its radially expanded position.

13. The sleeve set forth in claim 1 wherein slots in said second end portions terminate short of but in juxtaposition to said rib, while the slots in said first end portion terminate axially inside said rib, and said first axial end portion having a greater axial extent than said second axial end portion, and said fingers in said first end portion each including a radially extending portion for locking engagement with another member; and a first group of said first portion fingers having said radially extending shoulders at the axial outer end of said first portion, while others of said fingers have said radially extending shoulders intermediate said first radially extending shoulders and said rib.

15. A sleeve for insertion into a hollow core member and having a plurality of circumferentially displaced, radially inwardly opening latch receptacles adjacent one end, a radially inwardly extending annular shoulder axially inward of said receptacles with respect to said one end and inside the core, and an annular camming surface axially inwardly of said annular shoulder, the improved sleeve comprising: a unitary cylindrical body having first and second axial end portions and consisting of resilient molded plastic type material; an axially central annular portion separating said first and second axial end portions; each axial end portion having a plurality of slots axially extending from said annular portion to the respective ends such that each said axial end portion consists of a plurality of axially extending resilient fingers; said first axial end portion having a greater axial extent than said second axial end portion; said axially extending fingers in said first axial end portion being of first and second types, a plurality of fingers of each said type, said second type fingers having a radially outward extending locking portion at the axial outward extremity of said first axial end portion, said second type finger having a radially outwardly extending detent portion axially intermediate said annular portion and said locking portions; and at least one first type finger being circumferentially interposed between any two of said second type fingers.

16. A sleeve for insertion into a hollow core member and having a plurality of circumferentially displaced, radially inwardly opening latch receptacles adjacent one end, a radially inwardly extending annular shoulder axially inward of said receptacles with respect to said one end and inside the core, and an annular camming surface axially inwardly of said annular shoulder, the improved sleeve comprising: a unitary cylindrical body having first and second axial end portions and consisting of resilient material; each axial end portion having a plurality of slots axially extending from the respective ends substantially to a common circumferential line about said sleeve such that each said axial end portion consists of a plurality of extending resilient fingers axially extending from said common circumferential lines; said slots in said first axial end portion being circumferentially displaced from slots in said second axial end portion; and said first axial end portion having some fingers longer than others with each said other fingers being circumferentially interposed between two of said some fingers, each said fingers having radially extending detent portions at their respective axial outer end portions.

17. A releasable latching assembly for selective releasable engagement with an annular latch, the improvement including in combination: a body member to be latched having an axis of latching and a concentric cylindrical cavity; a first portion of said cavity having a first inside diameter and including latch receptacles symmetrically disposed about the cavity; an axially outwardly facing shoulder at the inner end of said cylindrical cavity and a frustro-conical surface extending axially inward concentric with said axis from said outwardly axially facing shoulder; a resilient tubular sleeve disposed in said cavity and having first and second axial end portions; an axially central annular portion separating said first and second axial end portions and disposed in said cylindrical cavity intermediate said axially facing shoulder and said locking means; said sleeve having an outside diameter less than the inside diameter of said cylindrical portion, but an outside diameter greater than the inside diameters of said frustro-conical section; each axial end portion of said sleeve having a plurality of slots axially extending from said central annular portion to the respective ends of said sleeve, such that each said axial end portion consists of a plurality of axially extending resilient fingers; said slots in said first axial end portion being circumferentially displaced from said slots in said second axial end portion; said first axial end portion having a greater axial extent than said second axial end portion; said frustro-conical surface radially inwardly urging fingers in said second axial end portion whereby fingers in said first axial end portion are radially outwardly urged with the central portion of said sleeve being free to move within said first cylindrical cavity; said axially extending fingers in said first axial end portion being of first and second types, a plurality of such fingers of each said type, said second type fingers having a radially outwardly extending locking portion extending respectively into said receptacles in said surface of said cylindrical cavity and being symmetrically disposed circumferentially of said sleeve, each said first type of fingers extending outwardly of said cylindrical cavity and including a radial outwardly extending locking shoulder substantially parallel to a surface of said member to be latched immediately adjacent and circumferentially disposed with respect to said cylindrical cavity; the arrangement being such that the radial inward urging on said fingers in said second axial fingers urges the fingers in said first axial end portion radially outwardly in a symmetrical uniform manner.

19. A releasable latching assembly for selective releasable engagement with an annular latch, the improvement including in combination: a body member to be latched having an axis of latching and a concentric cylindrical cavity; a first portion of said cavity having a first inside diameter and including latch receptacle means symmetrically disposed about said cavity; an axially outwardly facing shoulder at the inner end of said cylindrical cavity and a frustro-conical surface extending axially inward from said outwardly axially facing shoulder and concentric with said axis; a resilient tubular sleeve disposed in said cavity and having first and second axial end portions; an axially central annular portion separating said first and second axial end portions and disposed in said cylindrical cavity intermediate said axially facing shoulder and said locking means; said sleeve having an outside diameter less than the inside diameter of said cylindrical portion, but an outside diameter greater than the inside diameters of said frustro-conical section; each axial end portion of said sleeve having a plurality of slots axially extending from said central annular portion To the respective ends of said sleeve, such that each said axial end portion consists of a plurality of axially extending resilient fingers; said frustro-conical surface radially inwardly urging fingers in said second axial end portion whereby fingers in said first axial end portion are radially outwardly urged with the central portion of said sleeve being free to move within said first cylindrical cavity; the arrangement being such that the radial inward urging on said fingers in said second axial fingers urges the fingers in said first axial end portion radially outwardly in a symmetrical uniform manner.