US 20020038969 A1
A headrest mounting for a seat, e.g,. for a motor vehicle, includes a mounting member (15) fitted in the seat backrest and affording an upwardly-open passage (21) for sliding reception of a downwardly extending headrest post (13); a locking member (25) extending transversely of the passage and having an opening (27) through which the post extends; spring means (31) biasing said locking member to become more inclined from the perpendicular to the longitudinal axis of the post, so boundaries of said opening frictionally grip the post, and release means (23, 41) for causing the locking member to be oriented more nearly perpendicular to the longitudinal axis of the post to release the post for longitudinal movement within said passage.
1. A mounting member adapted to be fitted in a seat backrest and affording an upwardly-open passage for sliding reception of a downwardly extending headrest post; further comprising a locking member extending transversely of the passage and having an opening through which the post extends; spring means biasing said locking member to become more inclined from the perpendicular to the longitudinal axis of the post, so boundaries of said opening frictionally grip the post, and release means for causing the locking member to be oriented more nearly perpendicular to the longitudinal axis of the post to release the post for longitudinal movement within said passage.
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10. A seat comprising two mounting members for receiving two spaced parallel headrest posts, and wherein one of said mounting members is as claimed in
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 This invention relates to the mounting of headrests for seats. The invention has been devised primarly for motor vehicle scats, but it will be appreciated it will be applicable to seats generally, e.g. for other forms of transport, where similar or analogous requirements arise.
 A headrest is provided on a motor vehicle seat for constraining the head of an occupant of the seat against rearwards movement. This may be to enhance the comfort of the seat's occupant by enabling him or her to rest the head back against the headrest, but also has the purpose of preventing unconstrained rearward movement of the head if the vehicle is involved in a crash. Thereby “whiplash” injury to the neck of the seat's occupant may be reduced.
 In order that the headrest can fulfil this function, it is usual to provide some form of adjustability of the headrest, at least in the upwards and downwards direction relative to the seat to enable it to be appropriately positioned when the seat is occupied by persons of different height. Forwards and rearwards adjustment, and/or angular adjustment, of the headrest may also be provided for. The present invention relates to the provision of the upwards and downwards adjustment of a headrest relative to a seat.
 The most common configuration of headrest for a vehicle seat is that the part thereof which is contactable by the seat's occupant's head, which is upholstered to match the seat's upholstery and will herein be termed the pillow, is carried by a frame including spaced, substantially parallel, downwardly extending posts which are engageable in upwardly open sockets provided in the seat back. The extent to which the posts are received in the sockets determines the height of the headrest relative to the seat back. Locking means associated with the sockets (usually only one of them) enables the headrest to be fixed at the desired height.
 In many headrests, the locking means comprises detent means engageable with a number of formations such as notches spaced lengthwise of the headrest post so that the headrest height is fixed according to which one of the formations is engaged. This, of course, means that the headrest height can only be adjusted stepwise. Further, such notches can represent a trapping hazard to the fingers, particularly of children. It would be desirable if formations such as notches could be dispensed with, and if the headrest height could be adjusted steplessly within the limits determined by the length of the headrest posts and the dimensions of the sockets engaged thereby. There had been proposals for arrangements providing such stepless adjustment, but they have been complex arrangements and therefore expensive to manufacture.
 It is broadly the object of the present invention to provide for stepless adjustment of headrest height as above referred to, but in a simple and economical manner. Other objects and advantages of the invention will be pointed out in greater detail hereafter.
 According to the present invention, we provide a mounting member adapted to be fitted in a seat backrest and affording an upwardly-open passage for sliding reception of a downwardly extending headrest post; further comprising a locking member extending transversely of the passage and having an opening through which the post extends; spring means biasing said locking member to become more inclined from the perpendicular to the longitudinal axis of the post, so boundaries of said opening frictionally grip the post, and release means for causing the locking member to be oriented more nearly perpendicular to the longitudinal axis of the post to release the post for longitudinal movement within said passage.
 In order to be effective in frictionally gripping the post as above referred to, the opening in the locking member has to be dimensioned so that when the locking member lies perpendicular or close to perpendicular to the longitudinal axis of the post, opposed boundaries of the opening are clear of the post, but when the locking member is inclined from the perpendicular to the longitudinal axis of the post the boundaries of the post contact the latter.
 Such frictional gripping of a post by an inclined locking member is effective against movement of the post therethrough in one direction namely the direction which tends to cause the locking member to become more inclined from the perpendicular to the axis of the post. This increases the grip of the locking member on the post. Attempted movement of the post in the other direction, however, tends to return the locking member more nearly to the perpendicular to the axis of the post and thus decreases the grip of the locking member on the post, so the post is able to move in that direction through the locking member. In a mounting member for a vehicle seat headrest, the locking member should be effective against downwards movement of the headrest relative to the seat back so that if the headrest is to be moved in such direction the release means has to be operated, whilst upwards movement of the headrest relative to the seat back can be effected without requiring operation of the release means.
 Preferably the locking member is an element of sheet metal and it may be of resilient material having the spring means integral therewith.
 The locking member may be disposed in a lower part of the mounting member. This has the advantage that, if the post is marked by engagement of the locking member therewith, the marked part of the post will remain within the mounting member and thus invisible over at least the major part and preferably all the range of height adjustment of the headrest. The release means has to be operable from an accessible position on the mounting member, i.e. at a top portion thereof and accordingly preferably comprises a manually operable release member provided in an upper part, e.g. in a flange or escutcheon part at the top of the mounting member, connected to the locking member by transmission means.
 The transmission means conveniently comprises a pull rod member which may be of plastics material, integral with the release member.
 The release member may be or include a part which is movable, for causing release of the locking member, either generally in the direction of the length of the headrest post or, preferably, in the direction transversely to the length of the headrest post.
 The latter is easier to operate if the headrest is in its lowermost position close to the top of the seat backrest, with little room for a finger or fingers of a user to be inserted to operate the release member.
 As above described, a headrest usually comprises two spaced parallel posts which are engaged in respective mounting members spaced laterally of the seat. In general it will be sufficient for satisfactory looking of the headrest in an adjusted position if one of the mounting members is in accordance with the invention as above set forth.
 In this case, the other mounting member for the headrest may comprise releasable means for holding the respective headrest post captive to the mounting member. For complete removal of the headrest, action has to be taken to release the means which holds the headrest post captive to the second mounting member.
 The invention will now be described by way of example with reference to the accompanying drawings, of which:
FIG. 1 is a perspective view of a headrest mounting in accordance with the invention;
FIG. 2 is an enlarged and more detailed perspective view of one headrest mounting member as shown in FIG. 3;
FIG. 3 is a section through the mounting member of FIG. 2, in one operative condition;
FIG. 4 is a section as FIG. 3, but in an alternative operative condition;
FIG. 5 is an exploded perspective view of an alternative embodiment of headrest mounting member in accordance with the invention.
 Referring firstly to FIG. 1 of the drawings, a backrest part of a vehicle seat is indicated generally at 10 and a headrest generally at 11. The headrest comprises an upholstered pillow part 12 carried by a somewhat U-shaped frame of metal, e.g. steel, bar. The frame includes two spaced parallel posts 13, 14 which extend downwardly from the pillow part 12. The posts 13, 14 are received in respective mounting members 15, 16 which are fitted in the seat backrest at the top thereof and define upwardly-open passages in which the posts 13, 14 are received for sliding movement lengthwise of the posts so that the headrest is adjustable in respect of its height above the seat backrest. Although not related to the present invention the pillow 12 may be adjustable forwardly and rearwardly, and/or angularly, relative to the frame 11.
 Referring now to the remaining drawings, the mounting member 15 is shown in more detail in FIGS. 2, 3 and 4 and in the last mentioned drawing the post 13 is shown in situ. The mounting member comprises a moulded plastics body 20 in which is defined passage 21 for receiving the post 13 and at the top of the body 20 there is a flange or escutcheon formation 22 which accommodates release member 23 to be described in more detail hereafter. The escutcheon 22 lies on top of the upwardly presented top surface of the seat backrest 10 when the mounting member is fitted thereto.
 Towards the bottom of the body 20 there is a recess 24 in which is accommodated a locking member 25. The locking member 25, whose configuration is the same as the locking member in the embodiment of FIG. 5 and will be described in relation to that FIG., is of resilient metal such as spring steel and comprises a body part 26 in which there is an opening 27 surrounded by a rolled lip 28. The opening 27 is circular, slightly elongated in one direction, or other shape and dimensioned so that the post 13 can move freely through it when the body part 26 is perpendicular or nearly so to the longitudinal axis of the post, but the post is frictionally engaged by boundaries of the opening when the body part is more inclined to such perpendicular orientation. The body 26 is provided with spaced lugs 29 in one end face and with lugs 30 in the opposite end face. Adjacent the lugs 30, spring elements 31 are bent back to extend upwardly at an inclination to the body part 26 of the spring member. When received in recess 24, as most clearly seen in FIG. 3, lugs 30 engage a rear wall of the recess 24 while spring elements 31 engage a top part of the recess to bias the body part 26 of the locking member so that it is inclined downwardly within the recess.
 The release member 23, which is of moulded plastics material, is pivotably supported in the top part of the body 20 of the mounting member and has an integrally formed pull rod 33 guided in a formation 34 in the body 20 and having at its lower end a head 35. The pull rod extends between the lugs 29 of the locking member and the head 35 beneath the adjacent end of the locking member. The result is that pivoting of the release member by depressing its accessible end part, as shown in FIG. 4, displaces the pull rod 33 upwardly and causes the body 26 of the locking member to be moved from the position in which it is shown in FIG. 3 in which it is substantially inclined to the longitudinal axis of post 13 to a position in which it is close to perpendicular thereto.
 When the locking element has its body portion 26 inclined downwardly as shown in FIG. 3, opposite edges of the opening 27 therein fictionally grip the post 13 and prevent the post from moving downwardly within the mounting member. Attempted such downward movement of the post causes the post to be gripped even more tightly, but upward movement of the post is possible as it causes the body portion of the locking member to be moved slightly to an orientation more nearly perpendicular to the axis of the post so the latter is gripped less hard. When it is required to move the post downwardly within the mounting member, pivoting movement of the release member 23 causes the part of the body member 26 having the lugs 29 to be lifted by the head 35 at the lower end of the pull rod 33, to assume the orientation shown in FIG. 4 in which its frictional grip on the post 13 is released.
 Referring now to FIG. 5 of the drawings, this shows a mounting member which differs from that above described in respect only of the arrangement of its release member and its connection to pull rod 33. The pull rod 33 and its head 35, and the lower part of body 20 with its recess 24 for receiving locking member 25, are all as above described and will not be described again. The same reference numerals are used in relation to such parts. The FIG. 5 embodiment differs in having a top flange or escutcheon part 40 which receives a release member 41 for sliding movement perpendicularly to the axis of post 13. The release member 41 has an end abutment face 42 for engagement by a finger or thumb of a user, to press the release member in the direction of arrow 43 towards post 13. The top of pull rod 33 is forked to form two spaced parallel curved limbs of which one is indicated at 44, which join two lugs 45 on the release element 41 which lie to either side of the post 13 when received in the passage (46) in the mounting member. The limbs as 44 pass over respective correspondingly curved guide surfaces (not shown) in the upper part of the body 20 of the mounting member.
 Movement of the release member 41 in the direction of arrow 43 is transmitted by limbs 44 passing over their respective curved guide surfaces, to lift the pull rod 33 and disengage the locking member from the headrest post in the manner above described. The plastics material from which the release member 41, lugs 45, limbs 44 and pull rod 33 are integrally moulded is sufficiently flexible for the limbs to transmit to the pull rod the motion of the release member 41 in a direction perpendicular to that in which the pull rod is moved.
 To prevent inadvertent complete removal of the headrest 11 from the seat backrest 10, the mounting member 16 which receives the post 14 of the headrest may include a stop means which cooperates with a formation such as a radial protuberance at or adjacent the lowermost free end of post 14. The stop means may comprise a sleeve part of or associated with the mounting member 16, which is movable angularly about the axis of the post to a position in which such protuberance can pass through the sleeve, but which normally is in a position in which the protuberance cannot pass. Alternatively any other form of stop cooperating with the post, but movable to a releasing position to permit withdrawal of the post from the mounting member, may be utilised.
 The invention thus provides for stepless adjustment of a headrest in a particularly neat and economical manner.
 In the above described embodiments of headrest mounting the locking member is disposed towards the bottom of the mounting member and it is then necessary to provide transmission means between the release member and locking member. It would in alternative arrangements be possible to provide a locking member in the top part of the mounting member in which case it may be operated on directly by a release member. For example a release member movable agularly as the release member in the embodiments of FIGS. 2 to 4 may cause a corresponding movement directly in the locking member, or a transversely displaceable release member as in the embodiment of FIG. 5 may have a cam formation or formations which engage the locking member.
 In the present specification “comprises” means “includes or consists of” and “comprising” means “including or consisting of”
 The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.