A height-adjustable armrest for a chair includes a body, a coupling seat, and an adjusting device mounted to the coupling seat. The body includes an arm support section for supporting an arm of a user. The body further includes a tubular section having a vertical slot with a plurality of vertically spaced positioning grooves. The coupling seat includes a longitudinal hole so as to be mounted around the tubular section of the body. The adjusting device includes a push button and a positioning member having a positioning section that is releasably and selectively engaged in one of the positioning grooves. The positioning section of the positioning member is disengaged from the positioning grooves when the push button is pushed, allowing adjustment of a height of the body.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an armrest for a chair. In particular, the present invention relates to a height-adjustable armrest for a chair.

2. Description of the Related Art

It is common to mount two armrests on two sides of a chair to provide a support for the arms of the user. The armrests of most of chairs are fixed. Some of the chairs are designed to allow adjustment of the height of the armrests to suit users of different heights. An arrangement for adjusting the height of an armrest includes a knob that can be turned for adjusting purposes. However, the adjusting operation is inconvenient, and the height-adjustable armrest is not stable in structure.

SUMMARY OF THE INVENTION

An objective of the present invention is to provide an armrest that allows easy adjustment in a height thereof.

Another objective of the present invention is to provide a height-adjustable armrest having a stable structure.

A height-adjustable armrest for a chair in accordance with the present invention comprises a body, a coupling seat, an adjusting device, and a connecting frame. The connecting frame includes a first engaging portion securely connected to the coupling seat and a second engaging portion securely connected to a seat of a chair.

The body comprises an arm support section on an upper end thereof for supporting an arm of a user. The body further comprises a tubular section having a vertical slot with a plurality of vertically spaced positioning grooves. A reduced section is formed between a pair of the positioning grooves adjacent to each other.

The coupling seat comprises a longitudinal hole and mounted around the tubular section of the body. The coupling seat comprises a coupling section that has a through-hole in communication with the longitudinal hole of the coupling seat.

The adjusting device is mounted to the coupling section. The adjusting device comprises a positioning member, an elastic element, and a push button. The positioning member extends through the through-hole of the coupling seat and the vertical slot of the body. The positioning member includes a first end in the tubular section and a second end connected to the push button to move therewith. The first end of the positioning member includes a positioning section that is releasably and selectively engaged in one of the positioning grooves. The elastic element is mounted between the coupling seat and the push button for biasing the positioning section of the positioning member into one of the positioning grooves. The positioning section has a width greater than that of each reduced section of the body. The positioning section of the positioning member is disengaged from the positioning grooves when the push button is pushed, allowing adjustment of a height of the body.

Preferably, the body comprises a stop that abuts against the coupling seat when the body is in a lowest position thereof.

Preferably, the coupling seat includes a vertical guide groove in a periphery delimiting the longitudinal hole, and the body comprises a vertical guide rib slidably engaged in the vertical guide groove.

Preferably, the coupling section of the coupling seat comprises an annular wall on an outer periphery of the coupling seat. The through-hole is defined in an area delimited by the annular wall. An annular groove is defined in the area and surrounds the through-hole. The first end of the elastic element is received in the annular groove. The second end of the positioning member is preferably threaded. The push button includes a hollow shank extending from a side thereof, with a screw hole being defined in an end wall of the hollow shank for engaging with the threaded second end of the positioning member, and with the second end of the elastic element abutting against the end wall of the hollow shank.

Preferably, the coupling seat comprises an attachment section including a receiving hole. A positioning projection is formed on an end wall delimiting the receiving hole. The first engaging portion of the connecting frame is received in the receiving hole and includes a notch for engaging with the positioning projection.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring toFIGS. 1 through 4, a height-adjustable armrest for a chair in accordance with the present invention comprises a body1, a coupling seat2, an adjusting device3, and a connecting frame4.

The body1includes an arm support section11on an upper end thereof for supporting an arm of a user. The body1further includes a tubular section12that has a vertical slot13. A plurality of vertically spaced positioning grooves14are defined in a perimeter delimiting the vertical slot13, with a reduced section15defined between a pair of positioning grooves14adjacent to each other. Further, the body1includes at least one vertical guide rib17for preventing rotation of the body1, which will be described later.

The coupling seat2includes a longitudinal hole21so as to be mounted around the tubular section12. At least one vertical guide groove22is defined in a periphery delimiting the longitudinal hole21. The vertical guide rib17is slidably received in the vertical guide groove22for preventing rotation of the body1.

The coupling seat2further includes a coupling section23on an outer periphery thereof for coupling with the adjusting device3. The coupling section23includes an annular wall231, with a through-hole232extending through an area delimited by the annular wall231and in communication with the longitudinal hole21of the coupling seat2. Further, an annular groove233is defined in the area delimited by the annular wall231and surrounds the through-hole231. Further, the coupling seat2includes an attachment section24having a receiving hole241and a positioning projection242on an end wall delimiting the receiving hole241.

The adjusting device3includes a positioning member31, an elastic element32, and a push button33. The positioning member31extends through the through-hole232of the coupling seat2and the vertical slot13of the tubular section12. The positioning member31includes a first end311in the tubular section12of the body1and a second end313that is preferably threaded. The first end311includes a positioning section312that is releasably and selectively engaged in one of the positioning grooves14of the body1. The positioning section312has a width that is greater than that of each reduced section15of the body1.

The elastic element32may be a compression spring. The elastic element32includes an end received in the annular groove233of the coupling seat2. The push button33includes a hollow shank331extending from a side thereof, with a screw hole332defined in an end wall of the hollow shank331. The threaded second end313of the positioning member31is engaged with the screw hole332of the push button33. The other end of the elastic element32abuts against the end wall of the hollow shank331.

The connecting frame4includes an engaging portion41on an end thereof. The engaging portion41is fittingly received in the receiving hole241of the coupling seat2. The engaging portion41includes a notch42for engaging with the positioning projection242of the coupling seat2. This prevents rotation of the coupling seat2and provides a stable structure. Formed on the other end of the connecting frame4is an engaging portion43for engaging with a seat5of a chair, as shown inFIG. 4.

Referring toFIGS. 3 and 4, the push button33is normally in a released position in which the positioning section312of the positioning member31is positioned in one of the positioning grooves14under the action of the elastic element32.

Referring toFIGS. 5 and 6, when the push button33is pushed such that the positioning section312of the positioning member31is disengaged from the positioning grooves14(see the phantom lines inFIG. 5), the body1vertically moved until the arm support section11reaches the desired level, and the push button33is then released. Rotation of the body1is prevented by the vertical guide rib17of the body1that is slidably received in the vertical guide groove22of the coupling seat2. The vertical slot13is sized to allow smooth movement of the body1during adjustment of the height of the armrest.

When the body1reaches its lowest position shown inFIGS. 5 and 6, a stop16on the body1abuts against the coupling seat2to prevent further downward movement of the body1. This prevents the positioning member31from being damaged by an upper edge delimiting the vertical slot13in a case that the body1is subjected to a relatively large downward force while proceeding with adjustment of the height of the armrest.

The hollow shank331of the push button33moves inside the annular wall231of the coupling seat2, preventing deviation of the push button33. The adjusting operation is thus smooth, easy, and reliable.

Although a specific embodiment has been illustrated and described, numerous modifications and variations are still possible without departing from the essence of the invention. The scope of the invention is limited by the accompanying claims.