US-12616266-B1 - Quick-release headband ratchet mechanism

US12616266B1US 12616266 B1US12616266 B1US 12616266B1US-12616266-B1

Abstract

A headband ratchet mechanism for tightening/loosening the headband of a safety helmet is operated by a knob that rotates in tightening and loosening directions to tighten or loosen the headband about the head of a wearer of the safety helmet. A ratchet mechanism resists loosening of the headband during normal use of the safety helmet. A quick-release mechanism actuatable by the wearer enables headband tension to be relieved without rotating the knob.

Inventors

Joseph Anthony Milot, III

Assignees

PROTECTIVE INDUSTRIAL PRODUCTS, INC.

Dates

Publication Date: 20260505
Application Date: 20250409

Claims (17)

1 . A quick-release headband mechanism for tightening/loosening a headband of a safety helmet, comprising: a housing having open opposite first and second ends and configured to receive opposite end portions of the headband into an interior of the housing; a pinion gear having a plurality of gear teeth being disposed in the interior of the housing, the pinion gear being rotatable about an axis of rotation in a tightening direction and an opposite loosening direction; a knob and a torque transmission member each being disposed on the axis of rotation and rotatable about the axis of rotation, the torque transmission member being disposed on the axis of rotation between the knob and the pinion gear, the knob being exposed to enable a user to rotate the knob to tighten or loosen the headband; the knob comprising a through hole extending parallel with the axis of rotation through the knob and a plurality of teeth being disposed around the axis of rotation and facing the torque transmission member; the torque transmission member being non-rotatably connected to the pinion gear for conjoint rotation with the pinion gear, the torque transmission member comprising a plurality of teeth being disposed around the axis of rotation and facing the knob, the torque transmission member being relatively axially movable with respect to the knob along the axis of rotation towards and away from the knob between a first position wherein the torque transmission member teeth are meshed with the knob teeth and non-rotatably connect the torque transmission member with the knob, and a second position wherein the torque transmission member teeth are spaced apart from and are not meshed with the knob teeth wherein the torque transmission member is operatively disconnected from the knob; a spring being disposed to generate a spring force applied to the torque transmission member urging the torque transmission member to the second position, the spring being elastically deformable in response to the torque transmission member moving between first and second positions to generate spring force at both of the first and second positions of the torque transmission member; and an actuator being at least partially disposed in the knob bore and being axially movable with respect to the knob, the actuator capable of being pushed by a user to displace the torque transmission member from the first position to the second position whereby the torque transmission member and the pinion gear are rotatably released from the knob and can rotate independently of the knob.
2 . The quick-release headband mechanism of claim 1 wherein the spring is a curved disc spring being disposed against the housing and between the housing and the torque transmission member.
3 . The quick-release headband mechanism of claim 2 wherein the disc spring is non-rotatably connected to the torque transmission member and is conjointly rotatable with the torque transmission member.
4 . The quick-release headband mechanism of claim 1 comprising a pinion gear mounting boss extending along the axis of rotation surface of the housing and out of the housing to an upper end of the pinion gear mounting boss; and the pinion gear, spring, and the torque transmission member each comprising a respective through hole having an interior wall that closely receives the pinion gear mounting boss, the spring and the torque transmission member being disposed outside of the housing with the spring being disposed against the housing.
5 . The quick-release headband mechanism of claim 3 wherein the pinion gear mounting boss is a tubular member having an annular inner wall surrounding the interior of the tubular member, the inner wall defining a reduced diameter portion of the pinion gear mounting boss; and the actuator comprises a latch arm extending through the reduced diameter portion of the pinion gear mounting boss, the latch arm engaging against the reduced diameter portion of the inner wall and thereby limiting axial movement of the actuator away from the pinion gear mounting boss.
6 . The quick-release headband mechanism of claim 1 comprising a tubular knob mounting boss extending from the housing along the axis of rotation to an upper end of the knob mounting boss, the knob being rotatably mounted on the knob mounting boss, the spring and the torque transmission member being disposed inside the knob mounting boss.
7 . The quick-release headband mechanism of claim 1 wherein the torque transmission member comprises a flat surface facing the knob, the teeth of the torque transmission member extending axially from the said flat surface.
8 . The quick-release headband mechanism of claim 7 wherein the actuator engages against a tubular boss of the torque transmission member when urging the torque transmission member from the first position to the second position, the tubular boss being coaxial with the axis of rotation, the teeth of the torque transmission member surrounding the tubular boss.
9 . The quick release member of claim 1 wherein the actuator comprises a flat outer surface flush with an end of the knob bore when the torque transmission member is in the first position.
10 . The quick-release headband mechanism of claim 1 wherein the spring force generated by the spring is transmitted to the actuator and urges the actuator axially away from the pinion gear, the actuator engaging a fixed stop surface that limits axial movement of the actuator away from the spring.
11 . The quick-release headband mechanism of claim 10 wherein the actuator comprises a flat outer surface flush with an end of the knob bore when the actuator is engaged against the stop surface.
12 . A headband ratchet mechanism for tightening/loosening a headband of a safety helmet, comprising: a housing having open opposite first and second ends and configured to receive opposite end portions of the headband into an interior of the housing; a pinion gear having a plurality of gear teeth being disposed in the interior of the housing, the pinion gear being rotatable about an axis of rotation in a tightening direction and an opposite loosening direction; a pinion gear drive for driving the pinion gear in the tightening and opposite loosening directions, the pinion gear drive comprising ratchet gear, the knob being disposed on the axis of rotation and being rotatable about the axis of rotation in the tightening and loosening directions, the knob being accessible to a user to rotate the knob to tighten or loosen the headband, the ratchet gear being disposed on the axis of rotation between the knob and the pinion gear, the ratchet gear comprising a body being rotatable about the axis of rotation in the tightening and loosening directions and being normally non-rotatably connected to both the knob and the pinion gear; a ratchet mechanism comprising a ring gear, at least one pawl arm extending radially from the body of the ratchet gear, and a torque transmission member b being disposed between the ratchet gear and the knob on the axis of rotation, the torque transmission member being normally non-rotatably connected to the knob and conjointly rotatable with the knob, the torque transmission member comprising at least one drive member, each individual drive member of the at least one drive member being associated with a respective individual pawl arm of the at least one pawl arm; the ring gear normally surrounding the ratchet gear, the ring gear being coaxial with the ratchet gear with respect to the axis of rotation, the ring gear being fixed with respect to the axis of rotation and comprising a plurality of radially extending teeth wherein each tooth has a steep tooth angle on a first side thereof and a less-steep tooth angle on a second side thereof; each individual pawl arm of the at least one pawl arm being a resilient member extending away from the ratchet gear body to a free end portion of the individual pawl arm, the resiliency of the individual pawl arm urging the free end portion of the individual pawl arm to face towards the steep side of a tooth of the ring gear while the ratchet gear is stationary with respect to the axis of rotation, the steep sides of the plurality of teeth of the ring gear being disposed to engage against the free end portion of the individual pawl arm and resist and prevent rotation of the ratchet gear in the loosening direction in response to a force applied to the pinion gear teeth urging rotation of the pinion gear in the loosening direction; each individual drive member of the at least one drive member of the torque transmission member being disposed to extend parallel with the axis of rotation to the ratchet gear, the individual drive member being disposed between the ratchet gear body and the pawl arm associated with the individual drive member, the individual drive member being disposed to engage against a first portion of the associated pawl arm when the torque transmission member rotates in the tightening direction that urges the ratchet gear to rotate in the tightening direction whereby the associated pawl arm slides over the less-steep sides of the plurality of ring gear teeth during rotation of the ratchet gear in the tightening direction, and being disposed to engage against a second portion of the associated pawl arm when the knob is rotating in the loosening direction that urges the associated pawl arm away from engagement with the ring gear teeth whereby the associated pawl arm does not prevent rotation of the body in the loosening direction; and a release mechanism for selectively disconnecting the knob from the pinion gear comprising an actuator, a spring, and the torque transmission member comprising a plurality of teeth facing the knob, the knob comprising a plurality of teeth facing the torque transmission member, the torque transmission member being relatively axially movable with respect to the knob towards and away from the knob between a first position wherein the torque transmission member teeth are meshed with the knob teeth wherein the meshed teeth non-rotatably connect the torque transmission member with the knob and a second position wherein the torque transmission member teeth are spaced apart from and are not meshed with the knob teeth, the spring being disposed to generate a spring force applied to the torque transmission member urging the torque transmission member to the first position, the spring being elastically deformable in response to the torque transmission member moving between first and second positions to generate spring force at both of the first and second positions of the torque transmission member, the actuator being at least partially disposed in a knob bore and being axially movable with respect to the knob, the actuator capable of being pushed by a user to displace the torque transmission member from the first position to the second position whereby the torque transmission member and the pinion gear are both rotatably released from the knob and can rotate independently of the knob.
13 . The headband ratchet mechanism of claim 12 wherein the ratchet gear is axially movable along the axis of rotation between spaced apart first and second operating positions, the ratchet gear when in the first operating position being surrounded by the ring gear teeth and when in the second operating position not being surrounded by the ring gear teeth; and the torque transmission member pushing the ratchet gear from the first operating position to the second operating position when the torque transmission member moves from the first position of the torque transmission member to the second position of the torque transmission member.
14 . The headband ratchet mechanism of claim 13 wherein the spring generates a spring force applied to the ratchet gear urging the ratchet gear towards the first operating position that is transferred from the ratchet gear to the torque transmission member and thereby urging the torque transmission member towards the first position of the torque transmission member, the spring being elastically deformable in response to the ratchet gear moving between first and second operating positions to generate spring force at both of the first and second operating positions of the ratchet gear.
15 . The headband ratchet mechanism of claim 14 wherein the pinion gear drive comprises a pinion gear mounting boss and a knob mounting boss; and the pinion gear mounting boss extending along the axis of rotation from an interior surface of the housing and out of the housing to an upper end of the pinion gear mounting boss; and the pinion gear, spring, ratchet gear, and the torque transmission member each comprising a respective through hole having an interior wall that closely receives the pinion gear mounting boss.
16 . The headband ratchet mechanism of claim 12 wherein at least one leg extends parallel with the axis of rotation from the spring to the ratchet gear, the at least one leg non-rotatably connecting the spring and ratchet gear for conjoint rotation of the spring and ratchet gear.
17 . The headband ratchet mechanism of claim 12 wherein the knob has lost motion with respect to the pinion gear when each individual drive member of the at least one drive member is rotating between the first and second portions of the individual pawl arm of the at least one pawl arm associated with the individual drive member.

Description

FIELD OF THE DISCLOSURE This disclosure relates to safety helmets having a headband, and in particular, to headband adjustment mechanisms that enable the wearer of the safety helmet to adjust the length of the headband. BACKGROUND OF THE DISCLOSURE Safety helmets (also known as hard hats) are protective headgear that protect workers from injury from falling objects or other hazards. The safety helmet is secured to the head by a headband suspended by the safety helmet that goes around the head of the wearer. The fit of the headband can be adjusted by a headband adjustment mechanism having an exposed knob that can be rotated in opposite directions to tighten or loosen the headband. The knob drives a pinion gear P (see FIG. 66) that engages rack teeth formed in opposite end portions H1, H2 of the headband as shown in FIG. 66. An example of a headband ratchet mechanism for a safety helmet is disclosed in Binduga, U.S. Pat. No. 5,950,245. There is a need for an improved headband adjustment mechanism that enables the quick-release of headband tension without rotating the knob but also functions to resist lengthening of the headband while the knob is stationary and not being used by the user to lengthen or shorten the headband. SUMMARY OF THE DISCLOSURE Disclosed is an improved headband adjustment mechanism for a safety helmet that enables the quick-release of headband tension without rotating the knob but also functions to resist lengthening of a tightened headband while the knob is stationary and not being used by the wearer of the safety helmet to lengthen or shorten the headband. An embodiment of an improved headband adjustment mechanism formed as a quick-release headband ratchet mechanism in accordance with this disclosure includes a pinion gear rotatable about an axis of rotation in a tightening and loosening direction and an exposed knob normally non-rotatably connected to the pinion gear that enables a user to selectively rotate the pinion gear in the tightening or loosening direction. A ratchet mechanism includes a ratchet gear and a ring gear. The ratchet gear is non-rotatably connected to the pinion gear for conjoint rotation with the pinion gear. The ratchet gear is normally surrounded by the stationary ring gear having ratchet teeth disposed about a body of the ratchet gear. The ratchet gear includes at least one elastically resilient pawl arm extending from the ratchet gear body radially away from the body and circumferentially in the loosening direction of rotation. The resiliency of the pawl arm normally urges the free end of the pawl arm against the ratchet teeth. While the knob is stationary, force applied to the pinion gear by a tightened headband urging the pinion gear to rotate in the loosening direction is resisted by the free end of the pawl arm engaging a steep side of a ratchet gear tooth, resisting and preventing the pinion gear from continued rotation in the loosening direction. The knob is normally non-rotatably connected to the ratchet gear by at least one drive member extending parallel with the axis of rotation and associated with a respective pawl arm. The drive member is received between the respective pawl arm and the ratchet gear body. Rotation of the knob in the tightening direction forces the drive member against an end of the respective pawl arm and drives the ratchet gear in the tightening direction. The free end of the respective pawl arm slides over the opposite less step sides of the ratchet gear teeth enabling rotation of the ratchet gear in the tightening direction. Rotation of the knob in the loosening direction engages the drive member against the opposite end of the pawl arm that applies a force to the free end of the pawl arm moving the free end of the pawl arm radially inwardly and out of engagement with the ring gear teeth enabling rotation of the ratchet gear in the loosening direction. The embodiment of the quick-release headband ratchet mechanism further includes a release mechanism that selectively releases the pinion gear from the knob, enabling the pinion gear to “free-wheel” and rotate in the loosening direction in response to force applied to the pinion gear by a tightened headband. An embodiment of the release mechanism includes a torque transmission member disposed between the knob and the ratchet gear. The torque transmission member has teeth that meshably engage with knob teeth to selectively non-rotatably connect the torque transmission member and the knob. The torque transmission member in this embodiment carries the at least one drive members. The torque transmission member and the ratchet gear are both movably mounted with respect to the axis of rotation. A spring urges the ratchet gear and the torque transmission member to a first, normal operating position in which the teeth of the knob and torque transmission mesh with one another and the ratchet gear is surrounded by the ring gear. An exposed actuator enables a user to push the ratchet gear and