US6669178B2 - Air damper used in glove box of automobile

US6669178B2 - Air Damper Used in Glove Box of Automobile

The present patent application claims the benefit of earlier Japanese Patent Application No. 2000-76112 filed Mar. 17, 2000, the disclosure of which is incorporated herein by reference.

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Background of the Invention

1. Field of the Invention

This invention generally pertains to an air damper, particularly an improved design of a cylindrical air damper used in the glove box of an automobile.

2. Description of the Related Art

Traditional cylindrical air dampers fixed in automobile glove boxes are disclosed in references such as Japanese Utility Model Registration No. 2557064. These dampers reduce the abrupt opening of glove boxes and minimize noise from sudden openings. They work by allowing the glove box to pivot slowly around its axis against the force of gravity.

A conventional air damper includes a cylinder with two open ends and a moving piston inside. A string is attached to the piston and extends out of the cylinder. A valve at the base controls the air passing through the cylinder, and a guide cap at the other end directs the string. A compression coil spring is placed between the guide cap and the piston.

The air damper is affixed to the instrument panel, the back wall of the glove box. The string, extending from the guide cap, attaches to the glove box. When the glove box is unlocked, the string pulls out of the cylinder, moving the piston inside and compressing the spring. Air flows into the cylinder via the valve, creating a damping effect that allows the glove box to open slowly.

To close the glove box, the piston moves back toward the valve, driven by the spring's restoring force, pulling the string back into the cylinder. The valve opens to release air from the cylinder, allowing the piston to return smoothly to its home position.

The full open position of the glove box must be regulated. Typically, a guide groove on the instrument panel or its cover sheet manages this, housing a stopper pin that moves within the groove as the glove box opens or closes. However, using separate components for position regulation complicates the glove box structure and reduces storage capacity. It might be suggested that the air damper itself regulates the open position by utilizing the maximum compressed spring position. Yet, this approach has limitations: the spring weakens under excessive load, brittle parts of the damper may break, and the open position fluctuates due to inconsistent spring force. These issues have hindered the use of the air damper itself as a position regulator.

Summary of the Invention

This invention aims to address the aforementioned problems. The primary goal is to offer an enhanced air damper design for automobile glove boxes, capable of functioning as a means for regulating the glove box's full open position without damaging or deteriorating the compression coil spring.

To achieve this, the air damper comprises a cylinder with a first open end and a second end, a guide cap covering the first open end, and a piston movable within the cylinder. A compression coil spring is positioned between the piston and the guide cap, pushing the piston toward the cylinder's second end in the free state. A string attached to the piston extends out of the cylinder. A stopper mechanism is placed between the guide cap and the piston to halt the piston before the coil spring is fully compressed when the string pulls the piston toward the guide cap.

The stopper mechanism is located inside the compression coil spring, helping maintain the air damper's compact form without requiring additional space for the coil spring. The mechanism can be connected to either the guide cap or the piston.

Preferably, the piston includes a hook piece facing the guide cap. The hook is threaded with the string, so at least one end extends from the cylinder through the guide cap. Thus, the string is doubled at the hook and movable through it. The string's one end attaches to the glove box's side edge. When the box opens, the string pulls out of the cylinder, causing the piston to move toward the guide cap. Due to the stopper mechanism, the piston strikes the stopper before the spring is fully compressed, preventing spring deterioration by excessive glove box load. The stopper mechanism reliably defines the glove box's full open position, holding it stably according to the stopper's length.

Brief Description of the Drawings

Further objectives, features, and benefits of this invention will be evident from the detailed description and the accompanying drawings:

FIG. 1 depicts an exploded view of the preferred embodiment of the air damper.

FIG. 2 is a cross-sectional view of the piston used in the air damper as shown in FIG. 1.

FIG. 3 is a cross-sectional view of the guide cap utilized in the air damper as shown in FIG. 1.

FIG. 4 is a cross-sectional view of the fully assembled air damper unit.

FIG. 5 illustrates the air damper in a cross-sectional view when the glove box is fully open, with the piston contacting the guide cap's abutment wall.

FIG. 6 shows a cross-sectional view of a modified version of the air damper depicted in FIGS. 1 through 5.

Detailed Description of the Preferred Embodiment

FIG. 1 illustrates the preferred embodiment of the air damper in an exploded view. The air damper consists of a cylinder (1) with a first open end (13) and a second open end (3), and a piston (2) inside, which moves along the cylinder's axis. The first opening (13) serves as a leading port, while the second opening (3) functions as an air hole. A string (8) connects to the piston (2) to transfer the damper effect to the glove box. The string can be a lace, cord, or belt. A guide cap (6) at the leading port guides the string out of the cylinder. The air hole (3) features an end cap (5) with an air valve (4) between them. A compression coil spring (7) is placed in the cylinder between the piston and the guide cap. In its free state, the spring (7) pushes the piston (2) toward the end cap (5).

The cylinder (1) has an L-shaped hook (9) on its outer face near the leading portion to hook one end (8a) ofthe string (8). The piston (2) features O-rings (10) around its outer face and a hook piece (11) threaded with the string. The string (8) is doubled and movable through the hook piece, extending axially inside the cylinder. One end (8a) of the string is hooked at the L-shaped hook (9), while the other end (8b) attaches to a side edge of the glove box. In this example, both ends (8a and 8b) are looped.

FIG. 2 presents a cross-sectional view of the piston (2), with a ghost line indicating the string (8). The O-rings (10) are fitted into threaded forms on the piston's outer face. The hook piece (11) features a swelling wall that functions as a reel, allowing the string (8) to be pulled in both directions. The piston has an orifice (2a) at the bottom face.

FIG. 3 shows a cross-sectional view of the guide cap (6) attached to the cylinder's leading port. As illustrated in FIGS. 1 and 3, the guide cap (6) includes a pair of stopper plates (14a) with a partition (15) between them. The guide cap has a hole (12) to receive one end (8a) of the string and a guide hole (13) for the other end (8b) of the string to exit the cylinder. The string's doubled ends (8a and 8b) are separated by the partition (15) and inserted into the holes (12 and 13), respectively.

The stopper plates (14a) extend inside the compression coil spring (7) toward the hook piece (11) on the piston (2), eliminating the need for extra space and preventing the cylinder from becoming large.

During assembly of the air damper shown in FIGS. 1 through 3, the string (8) is threaded through the hook piece (11) on the piston (2), then pulled double inside the compression coil spring (7). Next, the piston and spring are inserted into the cylinder (1) from the leading port. The guide cap's hole (12) is threaded with one end (8a) of the spring and the guide hole (13) with the other end (8b) before attaching the guide cap to the cylinder. Finally, the guide cap is fixed to the cylinder, and one end (8a) of the spring hooks onto the L-shaped hook (9), assembling the damper into a single unit (FIG. 4). The stopper plates (14a) of the guide cap extend into the cylinder inside the compression coil spring.

When installing the air damper in an automobile glove box, the cylinder (1) is secured to the instrument panel or the attached cover. The looped end (8b) of the spring extending from the guide cap is pulled out and attached to the glove box's side edge. In the preferred embodiment, doubling the spring inside the cylinder results in a pull amount twice the piston's displacement.

When the glove box unlocks, it pivots and starts opening due to gravity. As it opens, the spring (8) pulls out of the cylinder, moving the piston (2) toward the guide cap (6) and compressing the coil spring (7). The air compressed inside the cylinder flows through the piston's orifice (2a), generating a damper effect that ensures the glove box opens gently.

The hook piece (11) on the piston hits the stopper plates' tips (14a) projecting from the guide cap before the coil spring fully compresses (FIG. 5). This prevents the piston from advancing further and defines the glove box's full open position stably without fluctuation. This design eliminates the need for extra regulation mechanisms.

Even in the full open position, the compression coil spring (7) is not entirely compressed. Therefore, the spring retains its strength, and the air damper avoids damage or breakage from full spring compression.

When closing the glove box, the piston (2) is pushed back by the coil spring's restoring force, retracting the string (8) inside the cylinder. The valve (4) opens to release air from the cylinder, ensuring the piston's smooth return.

FIG. 6 shows a modified air damper with stopper plates (14b) on the piston (2) sides adjacent to the hook piece (11), projecting toward the guide cap inside the coil spring. As in FIGS. 1 through 5, this maintains the air damper's compactness by housing the stopper plates within the coil spring.

In this modification (FIG. 6), the stopper plates' tips (14b) on the piston hit the guide cap before the coil spring can fully compress. This contact prevents the piston from moving further towards the guide cap and stably defines the glove box's full open position. Since the spring is protected from excessive load, it remains strong even if the glove box is kept open. This protection also extends to the air damper, avoiding damage to brittle parts.

Adjusting the stopper plates' length (14a or 14b) easily sets the glove box's full open position appropriately.

In summary, the air damper in this invention allows for smooth opening of the glove box and serves as a reliable means for regulating its full open position. The position can be easily adjusted by changing the stopper plates' length. The stopper plates also prevent overcompression of the coil spring, ensuring the air damper functions reliably without damage or wear to the coil spring.

Although the invention is described with preferred examples, it is not limited to these. Many modifications and substitutions are possible without departing from the invention's scope, as defined by the appended claims.