Tactile pin having overload protective function

Abstract

To provide an overload protective pin (an OP pin) used for a braille display.SOLUTION: Each OP pin in a braille display is arranged above an associated actuator pin, which allows the OP pins to be selectively driven upward or downward. This, in turn, allows the OP pins to be selectively positioned to generate Braille characters that can be sensed by a BLV user. However, when excessive forces are encountered (defined as forces beyond the standard sensing pressures applied by BLV users) the OP pins yield and are retracted to a position beneath an upper surface of the Braille display. This serves to protect both the OP pins and underlying actuator mechanisms. Once the excessive force is removed, the OP pin recovers to its original height.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to tactile pins for use in Braille displays, and more particularly, to tactile pins having features for reducing damage to the pins and associated displays when excessive force is applied. [Background technology]

[0002] Braille displays are used by individuals who are blind or otherwise have low vision (hereafter "BLV users"). Braille displays contain a series of pins that can be selectively raised or lowered to produce refreshable Braille characters. These pins, sometimes called tactile or dot pins, are designed to be sensed by the fingertips of the BLV user. The tactile pins are delicate and easily damaged. Even slight damage to the tactile pins can be perceived by the BLV user as a buzz or noise when reading the display. Significant damage to the tactile pins can result in the BLV user being unable to read the displayed Braille characters. Unfortunately, many tactile pin designs are easily damaged by the application of excessive force. This damage is often unintentional, such as when a Braille display is dropped by the user. In other cases, the destructive force is intentional, such as when a publicly accessible Braille display is destroyed.

[0003] Destruction can occur, for example, when a Braille display is incorporated into a public kiosk. These kiosks can be found in vending machines, information kiosks, or reservation terminals, or anywhere a BLV user needs to read or input data. The public nature of these displays and the fragile nature of existing pin designs pose a clear risk of damaging these displays and rendering them unusable. There are many ways in which a Braille or tactile display element can be damaged. For example, various lateral, vertical, or shear forces applied to the pin can be transferred to and damage the underlying actuator. Even if the underlying actuator is not damaged, the pin itself can be rendered unusable.

[0004] As a result of this, some public kiosks must pass certain safety standards. Under one standard, known as the ball impact test, a 50 mm, 500 g steel ball is dropped onto the surface of the braille display. This safety standard does not require the display to retain its functionality, only that the display does not pose a safety risk to the BLV user after the impact. Thus, there is a real need in the industry for higher standards, so that braille displays can retrain their functionality following large impacts and excessive force.

[0005] Little effort has been made to protect the tactile pins, but efforts have been made to protect various push button devices from damage. One such example is shown in U.S. Patent No. 6,765,164 to Lee et al. Lee discloses a push button design that resists damage upon application of excessive external force. The button includes first and second springs that can be resiliently compressed upon application of excessive force. In this manner, the switch components are protected from damage or breakage. Similarly, U.S. Patent No. 4,053,726 to Schaad discloses a push button electrical switch. The push button switch is slidable within an opening in the casing to a position where the push button is flush with the casing. In this manner, the force acting on the fixed contact means cannot exceed the force produced by the associated spring, thereby reducing the possibility of damage to the button.

[0006] The referenced push button does provide some degree of damage protection, but is used for an entirely different application and is not related to the unique challenges presented by tactile pins and braille displays. The referenced push button does not include any means for protecting the underlying actuator mechanism associated with the braille display. The tactile pin of the present disclosure is directed to overcoming these and other shortcomings known in the background art. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] U.S. Patent No. 6,765,164 [Patent Document 2] U.S. Pat. No. 4,053,726 Summary of the Invention

[0008] It is therefore an object of this disclosure to provide a haptic pin configuration with various overload protection features.

[0009] The disclosed overload protection pin provides several important advantages, including the ability to dissipate excess forces so as not to damage the underlying actuator mechanism.

[0010] A further possible advantage is achieved by locating an overload protection pin below an associated Braille display when excessive force is applied, thereby preventing the pin from becoming damaged or disabled.

[0011] Yet another possible advantage of the present system is that it provides a Braille display that can withstand the forces that may be encountered by publicly available kiosks.

[0012] These and other advantages are realized by incorporating overload protection pins ("OP pins") into the braille display. Each OP pin in the display is positioned above an associated actuator pin. This allows the OP pin to be selectively driven upwards or downwards by the associated actuator pin. The OP pins can therefore be positioned to generate braille characters that can be tactilely sensed by a BLV user. However, if excessive force beyond standard tactile sensing pressure is applied to the OP pin, the OP pin will yield and reduce its overall height below the top surface of the surrounding braille display. This helps protect both the OP pin as well as the underlying actuator mechanism. When the excessive force is removed, the OP pin will recover to its original height. There are various means by which the OP pin can be positioned below the surface of the braille display when subjected to excessive force. Examples of these means can include, but are not limited to, spring-loaded pins, buckling spring pins, plastic spring pins, and compressible foam pins.

[0013] Various embodiments of the present invention may have none, some, or all of these advantages.Other technical advantages of the present invention will be readily apparent to those skilled in the art. [Brief description of the drawings]

[0014] For a more complete understanding of the present disclosure, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: [Figure 1] FIG. 1 is an isometric view of a Braille kiosk with tactile pins using the overload protection feature of the present disclosure. [Figure 2A] A first embodiment of a haptic pin with overload protection is disclosed. [Figure 2B] A first embodiment of a haptic pin with overload protection is disclosed. [Figure 3A] A second embodiment of a haptic pin with overload protection is disclosed. [Figure 3B] A second embodiment of a haptic pin with overload protection is disclosed. [Figure 4A] A third embodiment of a haptic pin with overload protection is disclosed. [Figure 4B] A third embodiment of a haptic pin with overload protection is disclosed. [Figure 5A] A fourth embodiment of a haptic pin with overload protection is disclosed. [Figure 5B] A fourth embodiment of a haptic pin with overload protection is disclosed. [Figure 6A] A fifth embodiment of a haptic pin with overload protection is disclosed. [Figure 6B] A fifth embodiment of a haptic pin with overload protection is disclosed.

[0015] Like reference numbers are used throughout the several views of the drawings to refer to the same or similar elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] This disclosure relates to various overload protection pins ("OP pins") that may be used in a braille display. The OP pins include features to prevent or minimize damage when excessive force is applied. Each OP pin is located above an associated actuator pin, which allows the OP pin to be selectively driven upwards or downwards. This allows the OP pin to selectively generate braille characters that can be sensed by a BLV user. However, if subjected to excessive force, the OP pin will yield and retract to a position below the top surface of the braille display. This helps protect both the OP pin and the underlying actuator mechanism. Once the excessive force is removed, the OP pin will return to its original height and may be used again as a conventional tactile pin. This disclosure describes various means for providing overload protection to the OP pins. The various features of the disclosure and the manner in which they interrelate are described in more detail below.

[0017] FIG. 1 illustrates a Braille kiosk 10 according to the present disclosure. Although the illustrated display 10 is a Braille kiosk, the present disclosure may be readily used in connection with any of a wide variety of Braille displays, such as, for example, portable displays and tablets. The display 10 includes a screen 11 and a top surface 14 for implementing various user controls. The top surface 14 houses a centrally located refreshable Braille display with an array of tactile pins that form a string of Braille characters. The individual Braille characters 16 may be formed of 6-dot characters or 8-dot characters, as is known in the art. The top surface of each pin 12 may be selectively positioned above the surface 14 of the display 10 to be perceived by a BLV user as a Braille character. Each of the individual pins may be an OP pin 12 configured according to any of the embodiments disclosed herein.

[0018] First embodiment 2A and 2B are detailed cross-sectional views of the OP pin 12 of the first embodiment. FIG. 2A shows the OP pin 12 in an uncompressed state with its top surface 20 extending above the surface 14 of the display 10. FIG. 2B shows the OP pin 12 in a compressed state with its top surface 20 positioned below the surface 14. The OP 12 of this embodiment includes a beam 18 that connects the collar 12a of the pin 12 to a base 18a. The base 18a contacts an actuator mechanism 26 that drives the OP pin 12. Such actuator mechanisms are known in the art and may use, for example, piezoelectric, magnetic, or electromagnetic drivers. The actuator mechanism 26 receives commands to drive a series of tactile pins, thereby refreshingly generating Braille characters. These known actuator mechanisms include delicate electronics that may be damaged by excessive force transmitted from the OP pin 12.

[0019] OP pin 12, consisting of 12, 12a, 18, 18a, and 20, may be manufactured as a single piece of molded plastic. Regardless of the manufacturing method, the beam 18 portion of OP pin 12 is thin enough to buckle when excessive force is applied. That is, when a force is applied that exceeds that applied by a user's finger, beam 18 buckles inward toward the central axis, thereby reducing the overall height of OP pin 12. It is also within the scope of the present invention for beam 18 to buckle outward in the opposite direction. As used herein, "excessive force" is defined as any force that exceeds that applied by a BLV user when reading a Braille display, a force that causes bottom 18a of OP pin 12 to crash against actuator mechanism 26, damaging actuator mechanism 26, or otherwise damaging top surface 20 of OP pin 12.

[0020] This reduction in the height of the OP pins 12 upon compression allows the top surfaces 20 of the pins 12 to be positioned below the surface 14 of the display (FIG. 2B). Thus, any additional forces on the display 10 are borne by the surface 14 of the display 10, rather than by the delicate OP pins 12. This configuration protects the integrity of both OP pins 12 as well as the sensitive components associated with the actuator mechanism 26. Other embodiments described below describe various alternative means for providing overload protection.

[0021] Second embodiment A second embodiment of the present disclosure is shown in FIGS. 3A and 3B, which are side and cross-sectional views of one of the OP pins 12 of the display 10. This embodiment and other alternative embodiments described below share many of the same features as the main embodiment. Thus, the same reference numbers refer to the same elements throughout the various figures. Each OP pin 12 includes an upper surface 20 that can be sensed by a BLV user when extended above the surface 14 of the display 10. Each OP pin 12 also includes a central shaft 22 having a lower end 22a. A coil spring 24 is positioned around the shaft 22. The lower end 22a of the shaft 22 contacts an actuator mechanism 26 that is used in selectively driving the OP pin 12 upward or downward. The actuator mechanism 26 is housed within a base 28. The OP pin 12 and shaft 22 can be reciprocated up and down within the base 28 by the actuator 26.

[0022] The overload protection in this second embodiment is provided by a coil spring 24 located around a centrally located shaft 22 and along a mid-extent of the pins 12. The coil spring 24 extends between the lower collar 12a of the OP pins 12 and the top surface 28a of the base 28. The spring 24 functions to isolate the actuator 26 from excessive forces applied to the OP pins 12. That is, when excessive forces are applied to one or more of the OP pins 12, the spring 24 compresses to slow the movement of the OP pins 12 and allow the top surface 20 to extend below the top surface 14. That is, the top ends 20 of the OP pins 12 move below the surface 14 of the display 10 prior to full compression of the spring 24. The size, spring constant, and pre-compression of the spring 24 are tailored to achieve this goal. In this manner, the spring 24 prevents excessive forces from being transmitted down the shaft 22 to the actuation mechanism 26 while still providing sufficient force to be tactilely sensed by the BLV user. The spring 24 reforms by decompressing following removal of the excess force, allowing the OP pin 12 to reset to its initial position with the top end 20 above the surface 14 of the display 10.

[0023] Third embodiment A third embodiment of the OP pin 12 is shown in Figures 4A-4B. In this third embodiment, the coil spring 24 is replaced with a buckling spring 34. Furthermore, the central shaft 22 is replaced with upper and lower offset mounting posts 32. Thus, the buckling spring 34 is offset from the central axis and connected to the OP pin 12 via the opposing mounting posts 32. When the OP pin 12 is subjected to a sufficiently high compressive force, the buckling spring 34 buckles toward the central axis of the OP pin 12. This then allows the OP pin 12 to fall below the surface 14 of the display 10 to prevent damage to the underlying actuation mechanism 26. The buckling spring 34 then reforms following removal of the force, thereby allowing the OP pin 12 to reset to its initial height above the surface 14.

[0024] Fourth embodiment 5A-5B show a fourth embodiment of the present disclosure. In this embodiment, the coil spring 24 is replaced with a plastic spring pin 42. In this embodiment, there is no central shaft. Rather, the plastic spring pin 42 is a single plastic part with a spring molded throughout it. When subjected to an overload force, the plastic spring pin 42 compresses itself upwards and downwards, causing the top end 20 of the OP pin 12 to extend below the top surface 14 of the display 10. The plastic spring pin 42 then reforms after removal of the force, allowing the plastic spring pin 42 to reset to its initial position.

[0025] Fifth embodiment 6A-6B relate to a multi-material OP pin 12. The pin 12 includes an upper region 52 formed from a hard elastic plastic and a lower region 54 formed from a compressible elastomer 56. In the illustrated embodiment, the lower region 54 takes the form of a frusto-conical shape in the uncompressed state (FIG. 6A). If excessive force is then applied, the foam 56 compresses and crushes the OP pin 12 into itself, thereby reducing the overall height of the pin. This positions the upper surface 20 of the OP pin 12 in a position below the display surface 14. Again, this protects both the OP pin 12 and the actuator mechanism 26. After the force is removed, the elastomer 56 resumes its original shape, returning the OP pin 12 to its initial position.

[0026] Although this disclosure has been described with respect to specific embodiments and generally associated methods, modifications and permutations of these embodiments and methods will be apparent to those skilled in the art. Thus, the above description of exemplary embodiments does not define or limit this disclosure. Other changes, substitutions, and alterations are possible without departing from the spirit and scope of this disclosure.

Claims

1. 1. A tactile pin with overload protection for use with a refreshable Braille display, the refreshable Braille display including an upper surface with a series of openings, the tactile pin being received within one of the series of openings, the tactile pin comprising: an upper range, a lower range, and an intermediate range therebetween, the upper range being rounded and adapted to be felt by a user's fingertip; a base for receiving the lower range of the tactile pins; an actuator mechanism associated with the base, the actuator mechanism receiving commands to selectively drive the tactile pins upwardly relative to the top surface of the Braille display to selectively generate refreshable Braille characters, the actuator mechanism including a sensitive component; and a coil spring positioned around the intermediate range of the tactile pins, the coil spring having a length and a spring constant selected such that when the spring is compressed the upper range of the tactile pins is positioned below the top surface of the Braille display, the length and the spring constant further selected to prevent any damage to the sensitive component when excessive force is applied. A tactile pin.

2. A braille display with overload protection, comprising: an upper range as perceived by a user; and tactile pins positioned within the display and adapted to be driven up and down to generate refreshable Braille characters; an actuator mechanism for actuating the haptic pins; Equipped with the tactile pin includes an upper extent adapted to be sensed by a user and a lower extent operatively connected to the actuator mechanism; a beam formed between the upper and lower extents of the haptic pin, the beam adapted to buckle when an excessive force is applied and adapted to unbuckle after the excessive force is removed; The beam functions to prevent damage to the haptic pins and the actuator mechanism. Braille display.

3. 3. The braille display of claim 2, wherein the length and thickness of the beams are selected such that the tactile pins are positioned below a surface of the braille display when the excessive force is applied.

4. 3. A braille display as claimed in claim 2, wherein the tactile pins are integrally moulded from plastic.

5. The braille display of claim 2 , wherein the beam buckles towards a central axis when the excessive force is applied.

6. The braille display of claim 2 , wherein the beams buckle away from a central axis when the excessive force is applied.

7. 1. A pin for use with a refreshable Braille display, comprising: an upper area intended to be perceived by a user, in which a series of pins are used to generate individual Braille characters; an actuator mechanism located within the base for selectively actuating the tactile pins as needed to form the individual Braille characters; and an overload protection means for preventing the pin from damaging the actuator mechanism when the excessive force is applied to the Braille display; A pin comprising:

8. The pin of claim 7 , wherein said overload protection means comprises an offset buckling spring interconnected between said pin and said base.

9. 8. The pin of claim 7, wherein said overload protection means comprises a plastic spring interconnected between said pin and said base.

10. 8. The pin of claim 7, wherein the overload protection means comprises a plastic beam extending between upper and lower extents of the pin.

11. 8. The pin of claim 7, wherein said overload protection means comprises a compressible elastomer formed in a lower extent of said pin.

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