GB2347726A

GB2347726A - A vibration alerter having the motor acting as an eccentrically mounted weight

Info

Publication number: GB2347726A
Application number: GB9905814A
Authority: GB
Inventors: Carl Carley
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 1999-03-12
Filing date: 1999-03-12
Publication date: 2000-09-13
Anticipated expiration: 2019-03-12
Also published as: GB9905814D0; GB2347726B

Abstract

A vibration alerter comprises a motor body 1 preferably having a non-rectilinear shaft 3. The end of the shaft 3, which is remote from the motor body 1, is mounted at a point away from the axis X-X of the motor body 1. Thus when the motor shaft rotates, the weight of the motor causes a vibration effect. The vibration may be used in a mobile telephone. Other embodiments are disclosed.

Description

VIBRATION ALERTER FIELD OF INVENTION The invention relates to a vibration alerter, and in particular to a vibration alerter for providing a vibration alarm instead of, or in addition to, an ordinary audible alarm to indicate an incoming call signal in a mobile telephone.

BACKGROUND The usual method of alerting a called party of an incoming telephone call, is to produce an audible alarm. However, in certain circumstances, it is undesirable to produce an audible alarm, particularly in the case of mobile telephones. To overcome this problem, vibration alerters have been developed to produce a vibrating call warning instead of the usual audible alarm. Such devices exist either as an integral part of the telephone, or as a detachable accessory that may be connected to the telephone when desired.

US5642413 (Little) discloses a vibration alerter according to the prior art, whereby the vibration effect is achieved using a DC motor having an eccentric weight attached to the motor shaft. The eccentric weight causes a vibration effect when the motor shaft is rotating. These devices have limitations insofar as the eccentric weight adds additional weight to the mobile telephone, which is contrary to the general desire to produce a light-weight device. Furthermore, the eccentric weight requires additional space to allow it to rotate freely when the motor shaft rotates. This additional space also goes against the general desire to make mobile telephones small and compact.

The aim of the present invention is to overcome these disadvantages by having a motor driven vibration alerter which does not use an additional eccentric weight.

SUMMARY OF THE INVENTION According to a first aspect of the present invention, there is provided a vibration alerter comprising a motor and an eccentric weight, characterised in that the body of the motor acts as the eccentric weight.

According to a second aspect of the invention, there is provided a vibration alerter having a casing and comprising a motor, the motor mounted on at least one motor shaft, the shaft having a first end at the motor and a second remote end, wherein the second end of the motor shaft is mounted to the casing at a point which is non-coincident with the axis of the motor body.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a vibration alerter according to the first aspect of the present invention; Figure 2 shows an implementation of the first aspect of the present invention; Figure 3 shows a vibration alerter according to a second aspect of the present invention; Figure 4 shows how DC connections are made to the motor according to the second aspect of the invention shown in Figure 3 ; Figure 5 shows in greater detail the flexi-circuit which enables the DC connections-to be made to the motor according to the second aspect of the invention; Figure 6 shows how the motor according to the second aspect of the invention may be mounted in the telephone casing; Figure 7 shows a third aspect of the present invention having a double crank arm mechanism; Figure 8 shows the mechanism of Figure 7 from a different perspective.

Figure 9 shows the third aspect of the invention having a flexi-circuit according to figure 5; and Figure 10-shows an example of a vibration alerter according to the prior art.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE PRESENT INVENTION Figure 10-shows a conventional vibration alerter in a telephone casing 105. A motor body 101 has a linear shaft-103, which is supported by the telephone casing 105 such that it is free to rotate. An eccentric weight 107 is fixed to the motor shaft 103, so that, when the motor shaft 103 rotates, it causes the eccentric weight 107 to rotate, which in turn causes the whole assembly to vibrate. This vibration creates the vibrating call warning that alerts the user that an incoming telephone call is being received.

This type of arrangement suffers from the disadvantage that the eccentric weight adds additional weight to the mobile phone, which, as stated above, is contrary to the general desire to reduce the weight of mobile phones.

Figure 1 shows a vibration alerter according to a preferred embodiment of the first aspect of the present invention. A motor body 1 is supported at one end by a flexible mounting element 7. The motor has a motor shaft 3 which is non-rectilinear. The end 9 of the non-rectilinear shaft remote from the motor preferably sits in a recess 11 formed in the casing 5. The casing 5 may be part of a telephone (if the vibration alerter forms an integral part thereof), or part of a detachable call warning device. The end 9 of the motor's non-rectilinear shaft 3 is preferably rounded so as to allow it to rotate freely, and prevent any damage from being caused to the recess 11 during use.

When the non-rectilinear shaft 3 rotates, the body of the motor 1 is made to rotate in a conical motion since the other end of the motor is mounted in the flexible mounting element 7. In this arrangement, the body 1 of the motor acts as the weight which causes the vibration effect.

Figure 2 shows a three-dimensional view of how the invention may be implemented in practice. The casing 5 has a recess 11 into which the rounded end 9 of the non-rectilinear shaft 3 sits. The base of the motor body 1 is secured to the other side of the casing via the flexible mounting element 7, for example silicon rubber. This acts as a pivot which allows the motor body 1 to rotate in a conical motion when the nonrectilinear shaft 3 rotates. The DC electrical connections 13 and 15 are embedded into the flexible mounting element 7, thereby relieving any mechanical stress on the electrical connecting wires.

Although the preferred embodiment shows the nonrectilinear shaft 3 comprising a single angular bend, it is to be understood that any other shape of shaft which achieves the same effect may be used, for example, the shaft may have more than one angular bend, or may be curved. The same desired effect will be achieved so long as the point at which the shaft attaches to the casing is not on the same axis as the motor.

Figure 3 shows an alternative embodiment according to a second aspect of the invention. The motor body 1 has two non-rectilinear shafts 3a and 3b. Preferably, each shaft has a double bend such that the axis of the shaft Y-Y where it connects to the casing is parallel with, but away from, the motor axis X-X.

In use, when the non-rectilinear shafts 3a and 3b rotate, the motor body will tend to rotate with the two shafts about the axis Y-Y, which makes it difficult to ensure satisfactory electrical connection to the motor.

To overcome this problem, electrical connections to the motor use a flexible electrical circuit (flexi-circuit) arrangement, as shown in Figure 4.

Figure 5 shows the flexi-circuit 17 in greater detail. It is made from a flexible material in which the DC electrical connecting wires 13 and 15 are embedded. A first adhesive portion 19 is provided to enable the flexi-circuit to be fixed to the motor body 1. A second adhesive portion 21 is provided to enable the other end of the flexi-circuit 17 to be adhered to a printed circuit board, or other element to which the DC electrical connections 13 and 15 are to be connected. A circular portion 23 is shaped so as to match the electrical connecting features of the DC motor. In particular, connections 13a and 15a are shaped so as to fit alongside the DC connections on the end face of the motor body 1.

The flexi-circuit 17 shown in Figures 4 and 5 provides the means which enables the DC electrical connections 13 and 15 to be connected to the motor, while preventing the aforementioned rotating effect in which the motor body 1 attempts to rotate. The flexicircuit 17 has sufficient leeway so that it allows the motor to crank without offering any resistance, yet is taut enough to prevent the motor body 1 from rotating, and hence keep its orientation generally constant.

Figure 6 shows a preferred arrangement for mounting the vibration alerter according to the second aspect of the invention. The casing 5 comprises two recesses 25. Each recess is shaped so as to allow a motor shaft to be snap-fitted into location. That is, the distance between surfaces 26a and 26b is such that it enables a motor shaft to be f-orcibly pushed into location, (ie. due to flexibility in the casing 5), yet restrains the motor shaft from escaping once located in place.

Figure 7 shows a further embodiment according to a third aspect of the present invention, in which the cranking effect is achieved by a crank arm arrangement.

In this embodiment, the motor-has two straight shafts 27a and 27b. Each motor shaft 27a and 27b is connected to a respective crank arm 29 and 31. Each crank arm 29 and 31 receives a second shaft 33 and 35, each shaft 33 and 35 being free to rotate within its respective crank arm 29 and 31. The opposite end of each shaft 33 and 35 sits in a recess provided in the mobile phone's casing, as shown for example in Figure 6. Bushes 37 and 39 are provided on each shaft 33 and 35 to prevent the cranking motor from touching the sides of the mobile phone's casing 5.

Figure 8 shows this embodiment from a different perspective.

In a similar way to that described in the second aspect of the invention, this embodiment requires a flexi-circuit 17 to be connected to the motor body, as shown in Figure 9, thus preventing the motor body from rotating. As before, the flexi-circuit 17 also allows the DC electrical connections to be made to the motor.

Each of the embodiments described above has the advantage that the body of the motor 1 acts as the eccentric weight for causing the vibration effect, thereby eliminating the need for a separate eccentric weight.

Although the preferred embodiments show the motor being directly mounted to the telephone casing, the invention equally applies to the motor being indirectly mounted to the casing. Furthermore, although the preferred embodiments refer to the vibration alerter being housed in the casing of a mobile phone, the vibration alerter may equally form part of a detachable accessory which, in use, is connected to a mobile phone, or indeed any other device.

Claims

1. A vibration alerter comprising a motor and an eccentric weight, characterised in that the body of the motor acts as the eccentric weight.

2. A vibration alerter as claimed in claim 1, wherein one end of the motor is mounted on a nonrectilinear shaft.

3. A vibration alerter as claimed in claim 2, wherein the opposite end of the motor is mounted in a flexible mounting element enabling the motor to pivot about this point.

4. A vibration alerter as claimed in claim 3, wherein the flexible mounting element is a rubber housing.

5. A vibration alerter as claimed in claim 2, wherein the other end of the motor is also mounted on a non-rectilinear shaft.

6. A vibration alerter as claimed in claim 5, wherein each non-rectilinear shaft comprises first and second bends, arranged such that the end portion of each non-rectilinear shaft is parallel with, but noncoincident with, the axis of the motor.

7. A vibration alerter as claimed in claim 1, wherein the motor is mounted on each end by two crank arm assemblies.

8. A vibration alerter as claimed in claim 7, wherein each crank arm assembly comprises a crank arm which is fixedly connected to a corresponding linear motor shaft, each crank arm also being connected to a second linear shaft, the other end of which is used to mount the motor.

9. A vibration alerter as claimed in any one of claims 2 to 8, wherein the end of each shaft is mounted in a recess located in the housing of the vibration alerter.

10. A vibration alerter as claimed in claim 9, wherein the recess allows each shaft to be snap-fitted into location.

11. A vibration alerter as claimed in any one of claims 5 to 10, having means for maintaining the orientation of the motor generally constant.

12. A vibration alerter as claimed in claim 11, wherein the means for maintaining the orientation of the motor comprises a flexible electrical circuit.

13. A vibration alerter as claimed in claim 12, wherein the flexible electrical circuit comprises means for enabling an electrical connection to be made between the motor and a circuit board which controls the motor.

14. A vibration alerter as claimed in claims 12 or 13, wherein the flexible circuit comprises an adhesive portion at each end for affixing it to its respective fixing point.

15 A vibration alerter having a casing and comprising a motor, the motor mounted on at least one motor shaft, the shaft having a first end at the motor and a second remote end, wherein the second end of the motor shaft is mounted to the casing at a point which is non-coincident with the axis of the motor body.