GB2249080A

GB2249080A - Tape reels in cases: shielding from shock

Info

Publication number: GB2249080A
Application number: GB9120405A
Authority: GB
Inventors: Davis Wayne Chamberlin; Gerald John Niles; John Alfred Heveron
Original assignee: Minnesota Mining and Manufacturing Co
Current assignee: 3M Co
Priority date: 1990-10-22
Filing date: 1991-09-25
Publication date: 1992-04-29
Anticipated expiration: 2011-09-25
Also published as: GB2249080B; JPH04115159U; GB9120405D0

Abstract

To protect reel 14 mounted on hub 12 in case 10, from shock, two annular shock shields 20 surround the hub and comprise compressible V- or U-shaped rings 40. Each shield can rotate with reel 14, has friction tips 44 to reduce friction, is located by its centre ring 26, and compresses axially and radially. Each shield may be relieved to form spokes (Fig. 1), and alternatively (Fig. 6) instead of rings may have conical deformations extending axially of the circular shield. Shield tab 30 engages the reel. The shields may be moulded from defined plastics. <IMAGE>

Description

SHOCK SHIELD FOR SHIPPING CASES The present invention relates to protective devices for use in tape reel shipping or storage cases.

More particularly, the present invention relates to protective devices which permit rotation of a tape reel within a shipping or storage case and which also absorb shocks.

Tape reels, such as video or computer tape reels having a large diameter hub, are stored, handled, and shipped in shipping or storage cases with the tape reel frictionally placed on a central aligned hubs projecting from the side walls of the case. Such containers or cases are well known. Early containers included annular flexible rings over which the tape reels are fit to prevent the reels from rotating. This configuration was found to damage the tape when the case was dropped or mishandled.

U.S Patent No. 3,353,660 to Will, discloses a shipping container for tape reels having an annular friction-reducing bearing ring disposed in each container side wall. The bearing ring is slipped over each side wall hub to provide a surface on which the tape reel is seated.

This bearing ring prevents axial translational tape reel movement while permitting the reel to rotate with respect to the container when subject to external movements. In the embodiment of Figure 5, a pair of annular bosses are provided to increase the thickness of the bearing ring and provide additional support against bending forces.

However, while resisting bending forces, this bearing ring does not flex to provide axial shock absorption.

Additionally, there is no mechanism to prevent the bearing ring from rotating relative the tape reel to improve the protection afforded the tape reel.

There is no known shock shield which provides sufficient shock absorption for tape reels when the storage or shipping cases subjected to mechanical shock. None of the known tape reel cases provides an adequate level of protection against damage to the tape and tape reel during shipping, storage, and handling.

The present invention overcomes the deficiencies of the prior art devices with a shock shield for use with tape reel shipping or storage cases. The shock shield is formed of an annular body having a central axial hole which mounts within a case. The shock shield can be a complete annular ring or can have portions of the ring removed. In the latter configuration, while the overall shape is annular, the shock shield is essentially a central ring with radially extending arms which culminate in annular portions. A cylindrical axial ring is formed around the central axial hole to locate the shock shield within the case. The shock shield is shaped to permit a tape reel stored within the case to rotate around its axis within the case, and to absorb shocks and prevent case displacements from being transmitted to and damaging the tape reel.This is accomplished by compressible elements formed on the shield body. The compressible elements are annular bearing rings concentric with the annular circumference. The annular bearing rings have a generally V-shaped cross section and an axial height less than the axial height of the axial ring. Additionally, a compressible element may be formed on the cylindrical axial ring formed around the central axial hole.

Alternatively, the compressible elements formed on the shield body can be cone-shaped projections extending axially out of the plane of the shield body both above the plane of the shield body and below the plane of the shield body. The cone-shaped projections may be arranged randomly or in annular rings.

The shock shield of the present invention is more flexible and provides greater shock absorption characteristics-when subjected to mechanical shock than the prior art shields. Due to the reduced surface area contact between the shield and the case, friction is reduced, thereby improving the rotational ability of the tape reel as compared with prior art shields. This reduces the likelihood of damage to the tape reel during shipping, storage, and handling, and reduces production costs of the shield due to its reduced size and thickness. Furthermore, the shock shield is provided with at least one radially extending tab which is received in a complementarily shaped opening in the tape reel hub. Interaction between the tab and opening causes the tape reel to rotate with the shock shield.

Figure 1 is a top view of a shock shield according to the present invention.

Figure 2 is a cross-sectional view of the shock shield taken along line 2-2 of Figure 1, placed in a case and showing the shock shield in the uncompressed state.

Figure 3 is a cross-sectional view of the shock shield of Figure 2 showing the shock shield in a partially compressed state.

Figure 4 is a top view of the shock shield according to another embodiment of the present invention.

Figure 5 is a cross-sectional view of the shock shield taken along line 5-5 of Figure 4.

Figure 6 is a top view of the shock shield according to another embodiment of the present invention.

Figure 7 is a cross-sectional view of the shock shield taken along line 7-7 of Figure 6.

Referring first to Figures 1, 2, and 3 which illustrate the preferred embodiment of a shock shield 20, the shock shield 20 is formed of a generally annular shield body 22, although other shapes may be used. The shock shield 20 can be used with known hubbed cases 10 designed for use with similarly sized tape reels. The shock shield 20 has a central axial hole 24 which mounts around the central axial hub 12 of the case 10, and a cylindrical axial ring 26 defines the central axial hole 24. The cylindrical axial ring 26 provides a larger axial surface area contacting the case hub 12 to assist locating the shock shield 20 within the case 10. In use, two shock shields 20 are placed in each case 10, one on each side of a tape reel 14 to be stored.Each shock shield 20 is secured around a case side wall hub 12 in a known manner, such as by a securing lip 28 mounted on the case hub 12 to permit rotation of the shock shield 20 relative to the case wall while preventing the shock shield 20 from inadvertently sliding off of the hub 12. The cylindrical axial ring 26 extends beyond the general plane of the shield body 22 and fits over the case side wall hub 12.

The tape reel 14 is placed snugly between the shock shields 20 such that the tape reel 14 and the shock shields 20 rotate together when any rotation occurs. Furthermore, the shock shields 20 flex by compressing axially as well as radially in response to axial and radial forces, respectively.

The shock shield 20 is shaped to permit a tape reel 14 stored within the case 10 to rotate around its axis within the case 10 and to absorb shocks and prevent sudden case displacements from being transmitted to and damaging the tape reel 14. Rotation of the tape reel 14 with the shock shield 20 is accomplished by physically connecting the two together. The shock shield 20 is provided with at least one axially extending tab 30 mounted on the shield body 22 adjacent the cylindrical axial ring 26. The tab 30 is received in an opening 16 in the tape reel hub 18.

Preferably the opening 16 and the tab 30 are complementarily-shaped. Interaction between the tab 30 and opening 16 causes the tape reel 14 to rotate with the shock shield 20 and eliminates the possibility of relative rotation between the tape reel 14 and the shock shield 20 as was common with known bearing rings. Preferably the tab 30 is formed on a portion of the shield body 22 that is separated from the remainder of the shield body 22 on a majority of its perimeter by a thin peripheral gap. This facilitates molding of the shock Shield 20.

As shown in the embodiment of Figures 1, 2, and 3, the shield body 22 preferably is not solid to simplify molding. The shield body 22 includes four members 32 which radially extend from the cylindrical axial ring 26 and are uniformly disposed around the axial ring 26. Each radial member 32 culminates in a peripheral annular circumferential portion 34 such that the four circumferential portions 34 extend for 3360 or 93.3% of the total circumference of the shield body 22. Preferably, the radial members 32 widen from the axial ring 26 to the circumferential portions 34, as illustrated. It is also preferred that all of the connections between the members 32, the axial ring 26, and the circumferential portions 34 be radiused equally. This non-solid configuration enhances the ability of the shock shield 20 to twist.

In an alternate embodiment shown in Figures 4 and 5, the shield body 22 is formed as a solid annulus 36 or can be formed with radial slits (not shown) in the shield body 22 to improve axial flexion of the shock shield 20.

Shock absorption and the prevention of sudden case displacements from being transmitted to and damaging the tape reel 14 are accomplished by compressible elements 38 formed on the shield body 22. The compressible elements 38 preferably are annular bearing rings 40 concentric with the cylindrical axial ring 26, which may or may not be perpendicular to the radius of the shield 20. Two or three annular bearing rings 40 are preferably used. In the embodiment of Figures 1, 2, and 3 only two rings 40 are used, and two and one-half rings 49 are used in the Figures 4 and 5 embodiment. Additionally, one larger bearing ring 40 or many smaller bearing rings 40 also could be used.

The annular bearing rings 40 preferably have a generally V-shaped or U-shaped cross section and an axial height less than the axial height of the axial ring 26. Also, a compressible element 48 may be formed on the cylindrical axial ring 26 formed around the central axial hole 24.

This compressible element 48 can be formed as a radially inwardly extending portion of the cylindrical axial ring 26 as shown.

In the preferred embodiment as shown in Figures 2 and 3, two upright V shapes 42 are shown formed on the shock shield body 22. A plurality of friction tips 44 are provided on each annular V vertex 46. These friction tips 44 reduce the surface area of the shock shield 20 which contacts the inside walls of the case to reduce friction and promote freer rotation of the shock shield 20 within the case 10. Additionally, a compressible element 48 may be formed on the cylindrical axial ring 26 formed around the central axial hole 24. This compressible element 48 is an annular bearing ring and can simply be formed as a radially inwardly extending portion of the cylindrical axial ring 26 as illustrated.

In the embodiment of Figures 4 and 5, two and one-half upright V shapes 50 are formed on the solid annulus 36 of the shield body 20. The same body segments 52 which form the upright V shapes 50 form two and one-half inverted V shapes 54 such that each body segment 52 serves as half of an upright V 50 and half of an inverted V 54. A plurality of friction tips 44 are provided on each annular V vertex 56.

When the case 10 is subjected to axial forces, the shock shields 20 compress axially. The annular bearing rings 40 compress from the rest position shown in Figure 2 to that shown in Figure 3, in which the lower shock shield 20 is compressed between the tape reel 14 and the lower wall of the case 10 leaving a gap between the upper shock shield 20 and the tape reel 14. Each shock shield 20 can preferably withstand up to 67 N (15 lb) of force. When the case 10 is subjected to radial forces, the compressible element 48 on the cylindrical axial ring 26 compresses to absorb the forces.

Alternatively, as shown in Figures 6 and 7, the compressible elements 38 formed on the shield body 22 are cone-shaped projections 58 extending axially out of the plane of the shield body 22 such that some cone-shaped projections 58a extend above the plane of the shield body 22 and the other cone-shaped projections 58b extend below the plane of the shield body 22. The cone-shaped projections 58 can be randomly arranged on the shield body 22 or, as shown, may be arranged in a plurality of annular rings 60. When the cone-shaped projections 58 are arranged in an ordered manner, it is preferred that alternating cone-shaped projections 58a extend above the shield body 22 and the intermediate alternating cone-shaped projections 58b extend below the shield body 22.

At least the bearing surface of the shock shield 20 and preferably the entire shock shield 20 is formed of a hard, smooth, low friction material such as polymeric materials. Polyethylene, polytetrafluoroethylene, nylon, and other thermoplastic resins can be used. The material should have relatively low static and dynamic coefficients of friction with the inside surface of the case to permit the shock shield 20 to rotate with a tape reel within the case during movement of the case. Preferably, the shock shield 20 is formed of polyethylene by injection molding and has a thickness of from 0.10 to 0.28 cm (0.040 to 0.110 in). This shock shield 20 can withstand 67 N of force and can absorb a 90 cm (36 in) drop without bottoming out or damaging the tape reel.

The shock shield 20 is more flexible and provides greater shock absorption characteristics when subjected to mechanical shock than earlier shields. Due to the reduced surface contact area between the shield 20 and the case 14, friction is reduced, thereby improving the rotational ability of the tape reel. This reduces the likelihood of damage to the tape reel during shipping, storage, and handling. Additionally, the shock shield 20 is cheaper to produce due to its reduced size and thickness.

Claims

CLAIMS:

1. A shock shield for use with tape reel cases having a central axial hub for receiving a tape reel , the shock shield comprising: a shield body hAving a central axial hole for rotatably mounting on the central axial hub of the case , the shield body being rotatable together with a tape reel when both are disposed in the case ; and means for permitting a tape reel stored within the case to rotate around its axis within the case and for absorbing shocks and preventing case displacements from being transmitted to and damaging the tape reel , wherein the shock absorbing means comprises at least one compressible element formed on the shield body

2.The shock shield of claim 1 wherein the shield body is annular and further comprising a cylindrical axial ring formed around the central axial hole to provide a larger axial surface area contacting the case hub to assist locating the shock shield within the case.

3. The shock shield of claim 2 wherein the shock absorbing means further comprises at least one ring compressible element formed on the cylindrical axial ring formed around the central axial hole comprising an annular bearing ring

4. The shock shield of claim 2 wherein the compressible element comprises an annular bearing ring concentric with the cylindrical axial ring

5. The shock shield of claim 4 wherein the shock absorbing means comprises a plurality of concentric annular bearing rings .

6. The shock shield of claim 4 wherein the axial height of the annular bearing ring is less than the axial height of the cylindrical axial ring

7. The shock shield of claim 4 wherein the annular bearing ring has a generally V-shaped cross section, and wherein each V shape is formed of two body segments and each body segment forms adjacent upright and inverted V shapes ) such that each body segment serves as half of an upright V and half of -an adjacent inverted V.

8. The shock shield of claim 7 further comprising a plurality of friction tips provided on each annular V vertex to reduce the surface area of the shock shield which contacts the inside walls of the case to reduce friction and promote freer rotation of the shock shield within the case

9. The shock shield of claim 2 wherein the rotation permitting means comprises at least one axially extending tab mounted on the shield body , wherein the tab is received in an opening formed in the tape reel hub and wherein interaction between the tab and the tape reel hub opening causes the tape reel to rotate with the shock shield and eliminates relative rotation therebetween.

10. The shock shield of claim 2 wherein the shield body is formed of a plurality of members which radially extend from the cylindrical axial ring and culminate in a peripheral annular circumferential portion to form open areas between adjacent radially extending members to enhance the ability of the shock shield to twist, wherein the radially extending members widen from the cylindrical axial ring to the circumferential portions

11. The shock shield of claim 1 wherein the shock absorbing means comprises a plurality of compressible elements formed on the shield body , wherein each compressible element comprises a cone-shaped projection extending axially out of the plane of the shield body , and wherein some cone-shaped projections extend above the plane of the shield body and the other cone-shaped projections extend below the plane of the shield body

12. A shock shield as claimed in Claim 1 substantially as herein described with reference to the accompanying drawings.