Hand-held device, in particular a writing instrument, having two retractable heads

A writing instrument, comprising:

• a body extending along an axial direction and presenting a first axial end and a second axial end opposite from the first axial end along the axial direction;
• a single carriage housed in the body and movable in translation along the axial direction relative to the body, the single carriage carrying a first head and a second head opposite from the first head along the axial direction housed in the body and being movable in translation along the axial direction relative to the body and a single blocking device including a single cavity and at least one ball;
• the at least one ball is configured to block the single carriage relative to the body when, relative to a direction of gravity, the first axial end is below the second axial end, so that the first head is blocked relative to the body to project axially from the first axial end, while the second head is retracted into the body, and
• the at least one ball is configured to block the single carriage when, in the direction of gravity, the first axial end is above the second axial end, so that the second head is blocked relative to the body to project axially from the second axial end, while the first head is retracted into the body.

A writing instrument, comprising:

• a body extending along an axial direction and presenting a first axial end and a second axial end opposite from the first axial end along the axial direction;
• a first carriage and a second carriage housed in the body and movable in translation along the axial direction relative to the body, the first carriage carrying a first head and the second carriage carrying a second head opposite from the first head along the axial direction housed in the body and being movable in translation along the axial direction relative to the body and a single blocking device including a single cavity and at least one ball;
• wherein the at least one ball is configured to block the first carriage relative to the body when, relative to a direction of gravity, the first axial end is below the second axial end, so that the first head is blocked relative to the body to project axially from the first axial end, while the second head is retracted into the body, and
• wherein the at least one ball is configured to block the single carriage or the second carriage when, in the direction of gravity, the first axial end is above the second axial end, so that the second head is blocked relative to the body to project axially from the second axial end, while the first head is retracted into the body.