Patent Application
20250061817
This disclosure relates to tactile pins for use in Braille displays. More particularly, the present disclosure relates to tactile pins with features for reducing damage to the pin and the associated display upon application of excessive forces.
Braille displays are used by individuals who are blind or who otherwise suffer from low vision (hereinafter “BLV users”). Braille displays include a series of pins that can be selectively raised or lowered to generate refreshable Braille characters. These pins, sometimes referred to as tactile pins or dot pins, are designed to be sensed by the fingertips of the BLV user. Tactile pins are delicate and susceptible to damage. Even minor damage to tactile pins can be perceived by BLV users as static or noise when reading the display. Significant damage to tactile pins can result in the BLV user being unable to read the Braille characters being displayed. Unfortunately, many tactile pin designs are easily damaged upon the application of excessive forces. This damage is often unintentional, such as when a Braille display is dropped by the user. In other cases, destructive forces are intentional, such as when publicly accessible Braille displays are vandalized.
Vandalism can occur, for example, when Braille displays are incorporated into public kiosks. These kiosks can be found in locations where BLV users need to read or input data, such as vending machines, informational kiosks, or reservation terminals. The public nature of these displays and the vulnerable nature of existing pin designs results in these displays being at a distinct risk of being damaged and rendered unusable. There are many ways that a Braille or tactile display element can be damaged. For example, various lateral, normal, 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.
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 it does not pose a safety risk to BLV users following the impact. Thus, there exists a real need in the industry for a higher standard, whereby a Braille display can retrain its functionality following significant impacts and excessive forces.
Although little, if any, effort has been directed to protecting tactile pins, efforts have been made to protect various push button devices from damage. One such example is illustrated in U.S. Pat. No. 6,765,164 to Lee et al. Lee discloses a push button design that resists damage upon the application of excessive external forces. The button includes first and second springs that can be elastically compressed upon the application of excessive forces. In this manner, switch components are protected from being damaged or broken. Similarly, U.S. Pat. No. 4,053,726 to Schaad discloses a push-button electrical switch. The push-button switch is slidable in an opening in a casing and into a position wherein the push-button is flush with the casing. In this way, the force on a fixed contact means cannot exceed the force developed by associated springs, thereby reducing the possibility of damage to the button.
Although the referenced pushbuttons offer some level of damage protection, they are used for totally different applications and are not concerned with the unique challenges presented by tactile pins and Braille displays. Nor do the referenced push buttons include means for protecting the underlying actuator mechanisms associated with a Braille display. The tactile pins of the present disclosure are aimed at overcoming these, and other shortcomings known in the background art.
It is therefore the object of this disclosure to provide a tactile pin design with various overload protection features.
The disclosed overload protection pins provide several important advantages. For example, they allow excessive forces to be distributed so that they do not damage the underlying actuator mechanisms.
A further possible advantage is achieved by positioning the overload protection pins beneath the associated Braille display upon the application of excessive forces, thereby ensuring that the pins do not become damaged or unusable.
Still yet another possible advantage of the present system is to provide a Braille display that can withstand the forces that may be encountered by a publicly available kiosk.
These and other advantages are realized by incorporating an overload protection pin (“OP Pin”) into a Braille display. Each OP Pin in the display is placed above an associated actuator pin. This allows the OP Pins to be selectively driven upwardly or downwardly by associated actuator pins. As such, the OP Pins can be positioned in a manner to generate Braille characters that can be tactilely sensed by the BLV user. However, when excessive forces beyond the standard tactile sensing pressures are applied to the OP Pin, it yields, reducing its overall height to become lower than the upper surface of the surrounding Braille display. This serves both to protect the OP Pins as well as the underlying actuator mechanisms. Once the excessive force is removed, the OP Pin recovers to its original height. There are a variety of means by which the OP Pin can be positioned below the surface of the Braille display upon encountering excessive forces. Examples of these means include but are not limited to: spring-loaded pins; buckle spring pins; plastic spring pins; and compressible foam pins.
Various embodiments of the invention may have none, some, or all of these advantages. Other technical advantages of the present invention will be readily apparent to one skilled in the art.
For a more complete understanding of the present disclosure and its advantages, reference is now made to the following descriptions, taken in conjunction with the accompanying drawings, in which:
Similar reference numerals are used to refer to the same or similar elements throughout the several views of the drawings.
This disclosure relates to various overload protection pins (“OP Pins”) that can be employed in a Braille display. The OP Pins include features to prevent or minimize damage upon the application of excessive forces. Each OP Pin is placed above an associated actuator pin, which allows the OP Pin to be selectively driven upwardly or downwardly. This, in turn, allows the OP Pins to selectively generate Braille characters that can be sensed by a BLV user. However, when excessive forces are encountered the OP Pins yield and are retracted to a position beneath the upper surface of the Braille display. This serves to protect both the OP Pins and the underlying actuator mechanisms. Once the excessive force is removed, the OP Pins recover to their original height and can once again be used as conventional tactile pins. The present disclosure describes various means for providing overload protection to the OP Pins. The various features of the present disclosure, and the manner in which they interrelate, are described in greater detail hereinafter.
OP Pin 12, consisting of 12, 12a, 18, 18a, and 20, can 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 upon the application of excessive forces. Namely, when forces beyond those applied by the fingers of a user are applied, beam 18 will buckle inwardly toward the central axis to thereby reduce the overall height of OP Pin 12. It is also within the scope of the present invention for beam 18 to buckle outwardly in the opposite direction. As used herein, an “excessive force” is defined as any force that exceeds the forces that would be applied by a BLV user in reading the Braille display, forces that would cause the bottom 18a of OP Pin 12 to impact and damage actuator mechanism 26, or forces that would otherwise damage the upper surface 20 of OP Pin 12.
This reduction in height of OP Pin 12 upon being compressed allows the upper surface 20 of pin 12 to be positioned beneath surface 14 of display (
The second embodiment of the disclosure is depicted in
The overload protection means of this second embodiment is provided by the coil spring 24 that is positioned about the centrally located shaft 22 and along the intermediate extent of the pin 12. This coil spring 24 extends between a lower collar 12a of OP Pin 12 and an upper surface 28a of base 28. Spring 24 functions to isolate actuator 26 from excessive forces applied to OP Pin 12. Namely, when an excessive force is applied to one or more OP Pins 12, spring 24 compresses to slow the travel of OP Pin 12 and allow upper surface 20 to extend below upper surface 14. Namely, prior to full compression of spring 24, the top portion 20 of OP Pin 12 will move down below surface 14 of display 10. The size, spring constant, and precompression of spring 24 are achieved to accomplish this objective. In this manner, spring 24 prevents any excessive forces from being transferred via shaft 22 to the underlying actuating mechanism 26, while providing adequate force for the BLV user to tactilely sense. Spring 24 reforms by uncompressing following the removal of the excessive force. This allows OP Pin 12 to reset to its initial position with the upper end 20 above the surface 14 of display 10.
A third embodiment of the OP Pin 12 is illustrated in
Although this disclosure has been described in terms of certain embodiments and generally associated methods, alterations and permutations of these embodiments and methods will be apparent to those skilled in the art. Accordingly, the above description of example embodiments does not define or constrain this disclosure. Other changes, substitutions, and alterations are also possible without departing from the spirit and scope of this disclosure.
