WO1999027694A1

WO1999027694A1 - Compressible bulk material spring for a communications device

Info

Publication number: WO1999027694A1
Application number: PCT/US1998/022718
Authority: WO
Inventors: Inc. Ericsson; Stacy N. Smith
Original assignee: Ericsson Ge Mobile Inc
Priority date: 1997-11-25
Filing date: 1998-10-27
Publication date: 1999-06-03
Also published as: AU1280599A

Abstract

A cellular telephone or like hand held communications device has hinged parts such as a cover or door on the housing body to cover the keypad of the phone when not in use, or a microphone stalk, or the like. The cover or door, often called a "flip", or other part, can pivot among several positions. A flip will pivot downwardly, away from the keypad, face, and body of the telephone, to allow a user then to dial or receive a call and otherwise to use the keypad. The flip or microphone has usually two detent positions to locate same in selected, closed and open orientations with respect to the telephone body. The detent positions are determined by a moveable, spring-loaded cam or detent positioned between a part of the flip or other part at the hinge axis and a detent member carried in the phone body, as is well known. Use of a resilient bulk compressible material as a spring, such as an open-cell polyurethane foam rubber material such as "Poron<TM>", rather than a metallic spring or the plastic material of the flip or door itself, provides potentially greater force to activate the detent system yet saves cost, size, and weight in the cellular phone or like device.

Description

COMPRESSIBLE BULK MATERIAL SPRING FOR A COMMUNICA TIONS DEVICE

BACKGROUND OF THE INVENTION

1. FIELD OF THE INVENTION The present invention relates to communications devices, particularly cellular telephones, having parts such as microphones which may be extended from the body of the phone, or hinged doors or covers, called "flips", which may cover the face and keypad of the device or be opened to use the phone features.

2. RELATED ART

"Flip" phones are well known in the cellular telephone and other portable communications device field. The cover, door, or "flip" protects the keypad and face

of such a device when it is not in use. Opening the flip both uncovers the keypad for use and also normally activates the phone to receive or to prepare to send a call. Opening the flip also positions the microphone input of the device farther from the

ear piece, so as to be nearer the user's mouth even in a very compact device. Other

devices have microphones on stalks that can be extended from the body of the phone into one or more use positions, held by spring detents in any of such positions.

It is known to have the flip of a phone positively positionable in closed and in

open positions, via a spring and detent system interposed between the flip and the body of the device on a hinge axis. Such devices have typically used either a coiled metal spring, a bent metal spring, or the strength and resilience of the plastic in the flip itself to force a detent member carried translatably in the body against a cooper¬

ating part in the pivoting flip at the hinge axis. Moving the flip from one stable posi¬

tion to the other requires the detent member to disengage from first set of surfaces in

the cooperating part against the spring force and then to re-engage with a second set

of surfaces in the second position. This arrangement provides a simple, long-lived

detent arrangement. However, a device with a coiled or bent metal spring is difficult

to assemble and to service. The metal spring takes up considerable space in the body

along the hinge line and also is costly. Engineering and building the flip with proper

resilience in the bridge between the ends of the hinge line is exacting and intricate

work, which increases both design and quality checking costs. No use of other mate¬

rials in the spring system of such a device is known, apart from plastic springs

molded to the shape and serving the same purpose as metal springs. Bulk com¬

pressible materials such as foam rubber are known to have resilient properties usable

for other purposes.

SUMMARY OF THE INVENTION

The present invention replaces the coiled or bent metal spring or the sensitive

flip design with a simple, resilient, bulk compressible material of much reduced size,

cost, and weight. The compressible bulk material may be of open cell polyurethane

foam; foam rubber available under the brand name Poron™ is particularly favored in

this use. Such Poron-brand foam rubber has little compression set and, if proper

density and firmness are chosen for the application, the spring has a favorable

force/deflection curve. The bulk material is punched from a sheet in, for instance, cylindrical plugs, and one or both ends of the material can be adhered to the body

and/or to the detent member along the hinge line in order to simplify assembly of the device.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is an exploded perspective view of the front body panel of a cellular

telephone with known flip, hinge axle, and detent members shown together with the bulk material spring of the present invention;

Fig. 2 is a cross-sectional view along the hinge line of a prior art device

showing the parts used with a known coiled metallic spring; and Fig. 3 is a cross-sectional view along the hinge line of a device of the present invention showing a bulk material spring according to one form of the invention.

THE PREFERRED EMBODIMENTS

The present invention replaces a coiled metal spring 10 mounted on a hinge

axis 12 of a door, cover, or "flip" 14 on the front 16P of a cellular phone or like communications device known in the prior art (as shown in Fig. 2). Instead, a shorter, lighter, less costly spring 20 is formed from a compressible, resilient bulk material, such as an open-cell polyurethane foam rubber (shown in Figs. 1 and 3). The known hinge pin 18, the detent member 22, and the cooperating part 24 on the

flip 14 of the known cellular phone face 16P may be unchanged. The spring cham¬

ber 26P in the body 28P of the face 16P along the hinge line 12 of the known devices

can be greatly reduced in size, as to 26 in Fig. 3, because of the changed material used for the new spring 20. Ends 30, 32 of the bulk material spring 20 can be ad- hered respectively to the body 28 of the phone face 16 along the hinge axis 12 and/or

to the detent member 22 to ease and improve the assembly process.

In particular, the detent member 22 in a flip phone may move about 1.5 mm

along the hinge axis from one stable position on the cooperating part 24 to an inter-

mediate position, before returning to the other stable position on that part, holding the

flip relatively firmly in desired closed or open positions. That 1.5 mm motion must

be accommodated while applying sufficient force on the detent member 22 to keep

the flip 14 firmly in either of its selected positions. Therefore, the dimensions and

other characteristics of a bulk material spring 20 can be selected to apply such a force

on a predominately linear part of its compression force deflection curve. Such a

curve is available for each commercial material, or one can be experimentally deter¬

mined. For the compressible bulk material trademarked as "Poron™ ", by Rogers

Corporation of Rogers, CT, curves are available for each of the densities and firm¬

nesses in which the material is made.

In one presently preferred form of the invention, a compression spring 10 in a

flip phone face 16P is replaced with a "Poron™" bulk material cylinder 20 of 4701-

12-30 pcf material ("very high modulus"), having a 4.8 mm (3/16 inch) length before

being compressed and a 5 mm (3/16 inch) diameter. This cylinder 20 is punched

from a sheet of open cell foam rubber of 4.8 mm (3/16 inch) uncompressed thick-

ness. The cylinder 20 exerts a 14 newton (3.1 pound) force against the detent mem¬

ber 22 when compressed to 65% of its original thickness and installed in the spring

chamber 26 of the body 28 of the phone face 16, according to the present invention.

Although not shown in the drawings, the body 28 of the phone face 16 can be further reduced in size by recapturing the space formerly used by the larger spring chamber

26P of the prior art.

Employing this invention, the hinge pin 18 could be replaced by a second detent member 22 cooperating with a second cooperating surface 24 in the flip 14. Alternatively, the detent and cooperating surfaces may be interchanged, so the moving detent is in the flip and the cooperating surfaces in the body, without departing

from the principles of this invention.

Ends 30 and 32 of the spring 20 may optionally be adhered with an acrylic or

acrylic blend pressure sensitive adhesive to the body 28 of the cell phone in the spring chamber 26 and/or to the detent member 22, respectively, prior to assembly of

the flip 14 onto the phone body 28. Using such adhesive can ease assembly procedures by holding the parts together until assembly and allow any needed disassembly of the flip 14 from the phone body 28..

In use, the detent member 22 is held in the position shown in Fig. 3 by the detent spring 20 when the flip 14 is in its closed position on the cell phone body 28.

When the flip 14 is pivoted by a user from the closed position of Fig. 1 or 3 to an open position (not shown), the detent member 22 will be moved to the left in the body 28, within the spring chamber 26, by the surface 24 on the flip 14. The detent

member 22 will move along the hinge axis 12. It will not rotate significantly due to a cooperating key (not shown) on the detent 22 and a keyway structure 34 in the body

28, shown in Fig. 1. This movement further compresses the spring 20. After the detent 22 has moved fully to the left, past a highest point or line of the cooperating part 24 in the flip 24 at the hinge axis 12, the spring 20 moves the detent 22 back to the right, to seat in a second stable position of the detent member 22 upon the surface

of the cooperating part 24. The flip is stable in that open position due to the forces

on the detent 22 exerted by the spring 20. Moving the flip to its closed position

causes the parts to move again, in a similar manner, unseating and then re-seating the

detent 22 into the first position on the cooperating part 24.

Similar adaptations can be made for using this invention in a microphone arm

or other part of a communications device.

Variations in the dimensions and materials used will not depart from the

scope and spirit of the invention. Reversal of parts and duplication of parts are also

part of the invention. All such variations as come within the scope of the appended

claims come within the scope of this invention.

Claims

I CLAIM AS MN INVENTION:

1. A cellular telephone comprising: a body with a front face thereof, a door or "flip" hinged to the body and moveable about a hinge line to selectively cover at least a part of said face of the telephone adjacent the

hinge line, a detent member carried in one of the flip and the body at one end of said

hinge line, the detent member being irrotatable with respect to one of the flip and the body but moveable along the hinge line therein, cooperating surfaces on the other of the flip and the body and providing stable resting conditions for the detent member only in first and second rotated positions of the flip with respect to the body and unstable resting positions between them,

a resilient, bulk compressible spring member exerting a spring force along the

hinge line,

which spring force is sufficient to urge the detent member into operable engagement with said cooperating surfaces.

2. A cellular telephone as defined in claim 1, wherein the compressible spring is comprised of an open-cell polyurethane foam.

3. A cellular telephone as defined in claim 2, wherein the foam is substantially that made under the brand name "PoronΓäó".

4. A cellular telephone as defined in claim 1, wherein the spring is

formed in a cylindrical shape.

5. A cellular telephone as defined in claim 1, whereon the spring is ad┬¼

hered at one end thereof to the body.

6. A cellular telephone as defined in claim 1, wherein the spring is ad┬¼

hered at one end thereof to the detent member.

7. A compact handheld communications device comprising a body with a face thereon, a door or "flip", a hinge connecting the door or flip to the body to cover at least a portion of the face adjacent said hinge, detent means for releasably holding the flip at desired angular positions about said hinge with respect to the face, and a spring loading the detent means, wherein the spring comprises a resilient, com┬¼

pressible, bulk material.

8. A device as defined in claim 7, wherein the spring comprises a foam

rubber member.

9. A device as defined in claim 7, wherein the spring comprises an open

cell foam rubber member.

10. A device as defined in claim 7, wherein the spring comprises an open cell polyurethane foam rubber member.

11. A device as defined in claim 7, wherein the spring comprises an open

cell polyurethane foam rubber member substantially identical to that sold as the

brand "PoronΓäó".

12. A device as defined in claim 7, wherein at least one end of the spring is adhered to at least one of the body and the detent member.

13. A device as defined in claim 7, wherein the spring is generally cylin-

dric in form.

14. A device as defined in claim 7, wherein the spring is stamped from a

sheet of resilient, bulk compressible material, the spring material being the thickness

of the uncompressed length of the member.

15. A communications device comprising a body with a moveable part

connected thereto for pivotal movement, a detent mechanism arranged between the

body and moveable part for releaseably holding the body and part in selected pivotal positions, and a spring loading the detent mechanism, wherein the spring comprises a resilient, compressible, bulk material.

16. A device as defined in claim 15, wherein the spring comprises a foam rubber member.

17. A device as defined in claim 15, wherein the spring comprises an open cell foam rubber member.

18. A device as defined in claim 15, wherein the spring comprises an open cell polyurethane foam rubber member.

19. A device as defined in claim 15, wherein the spring comprises an open cell polyurethane foam rubber member substantially identical to that sold as the brand "PoronΓäó".

20. A device as defined in claim 15, wherein at least one end of the spring is adhered to at least one of the body and the detent member.

21. A device as defined in claim 15, wherein the spring is generally cylin- dric in form.

22. A device as defined in claim 15, wherein the spring is stamped from a sheet of resilient, bulk compressible material, the spring material being the thickness of the uncompressed length of the member.