JPS60227711A - Continuous variable adjustable hinge - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This application is filed in U.S. Patent Application No. 595,591, filed April 2, 1984
Nuciously Variable Adjustab
This is a continuation-in-part application of Le Hinge) J.

The automatic seat recliner
), continuous variable adjustment is achieved by means of the ``Tauml J'' type, which in the manual case is gear-actuated by the rotation of a cam by the handle knob, which for each rotation of the hand knob has a Tormel mechanism. Self-locking friction of a single rocking element in relative forward movement between the outside and inside
friction) produces a sufficiently fixed condition for any position of continuous adjustment; however,
The overall adjustment between end positions is relatively slow compared to ratchet and pawl type glue Kleiner hinges, which ratchet and pawl pipe hinges are described in US Pat.
No. 947, commonly used in the United States, in which a cam actuated by the handle engages a pawl with teeth to adjust the rapid positioning of the seat back. release of the hand lever allows the pawl cam to lock in tooth engagement with the sector. In such hinges, the adjustable position is incrementally limited to a single tooth difference in relative sector and pawl positions.

Various approaches have been attempted to meet the need for sufficiently rapid manufacturing, as well as better adjustment than is possible with typical sectors and pawl tooth pitches. and U.S. Patent Nos. 4,223,946 and 43
No. 55846, additional "translation J (tran
slation) The linkage amplifies the angular movement of the toothed sector relative to the angular movement of the seat back and correspondingly reduces the angular displacement of the seat back for one tooth adjustment in the pawl and sector engagement. collaborated to do so. In other cases, as shown in U.S. Pat. No. 4,295,682, an exceptionally small tooth pitch has been adjusted by using a specific gripping action in a cam actuating mechanism, where the bias of the interengaging parts causes the teeth to engage. To more reliably prevent mismatches.

Although some improvements in the quality of adjustment have been achieved with such devices, the concept of true continuously variable adjustment combined with rapid global adjustment to the desired seat back position has not previously been demonstrated. was not fully achieved.

Various attempts at frictional fixation have not been able to withstand life tests under applied loads, and the safety standards (loads) are within the limits of space and cost constraints included in the parameters of seat hinge design. required within.

A complete solution to the long-standing quest for immediate, total and continuous objective regulation of the end has finally been achieved,
In that, the locking strength of the normal toothed sector and the pivoted pawl self-locking the cam actuation is maintained for continuous adjustment, and the continuous adjustment is adjustment is provided by allowing the pawl to vary within the pitch of a single tooth into a fully engaged position, followed by actuation of two cams at angularly related surfaces of the pawl. a relative cam-engaging surface for fixing the pawl in such adjusted holding position and adjusting the operating position of one tooth of the pawl to reach its initial fully engaged position. It involves providing a variable transition of . Self-locking angle (self-locking angle) not greater than 6" and effective throughout the entire range of cam travel
the shape of the pawl and cam to accommodate the preliminary variation of a single tooth of the pawl in achieving initial full tooth engagement with the sector, with is used with sufficient length of the cam surface.

In addition to two pivoted cam elements actuated simultaneously into the retracted position by a single handle, a link is provided to ensure the disengagement of the pawl teeth from the sector for preliminary tooth engagement. The preliminary tooth engagement is completed (by spring bias) before cam engagement of the pawl occurs. The extension arm of each cam is Biased by a connecting tension spring towards engagement of the pawls permitted by release of the hand lever.Each cam engagement may occur sequentially or simultaneously depending on the particular initial engagement position of the pawls. In either case, sufficient seating of the two cams in a fixed condition with all gaps closed is accomplished without displacing the pawls from their initial fully engaged position.

The triangular relationship of the two camshafts with pawl tooth retention and the effective angle of cam surface engagement provide self-resistance from any compressive pressure generated from tooth pressure in either direction. Allows setting a fixed angle. Therefore, although the strength and retention properties of the toothed pawl and sector structure held down by the cam are well preserved, it is difficult to provide a variation of a single toothed pawl and then two cams. The fixation achieves fully continuous variable adjustment combined with rapid global seat back positioning, which has been a fantasy goal of recliner designers for many years. was.

Seat bracket and backrest fixed against angular displacement by the action of two cams.
t) In any relative angular adjustment relationship of the brackets, the variable pawls can fully engage the tooth of the sector, and each cam has a variable self-locking angular displacement, which displacement in the adjustment Multiple variations can be made using the principle of at least enough to accommodate the full range of changes in a single tooth, thereby providing a full range of continuously variable bracket adjustment. However, through experimental testing, the applicant has discovered a particularly preferred embodiment, which has shown better durability under severe life tests without any adverse effects. A detailed description of such preferred embodiments is included in the continuing disclosure.
ion-in-part disclosure) to the embodiment of the parent application in FIGS. 1 and 2.

In preferred embodiments developed since the parent application was filed, the low tooth profile reduces the tooth angle and corresponding separation force between the pawl and the sector, e.g. It is used to allow the stress associated with both positive radial components to be reduced. The rotation of the two cams is reversed, so that
The force pattern on the pawl caused by the seat back loading forces the loaded cam toward a higher position, thereby creating greater resistance to creep from cyclic loading.

The claw is a tooth slide (tooth 5L) without a shaft.
ide) and is simplified to act as an axle arm. A new system of release and pawl controls adjusts the flat tooth end of the shallow-angle low tooth and the recoil end of the torque spring toward the sector to bias each cam toward the locked position. It is used to bias the pawl and move the teeth fully into engagement prior to installing the cam to secure the pawl in place. The shape of the cam that resists the load of the claw teeth is
Optimize the centering of the resultant force of the seat load torque on the sector and the tooth couple that tries to remove the pawl on the axis of the loaded cam shaft, and Ideal for providing a grooved cam profile to minimize deflection over a range.

With reference to FIG. 1, an upper hinge bracket 10 and a lower hinge bracket are pivotally connected at 12, each hinge bracket being connected to a seat back or a seat of a motor vehicle. can be done.

The circular sector of the upper bracket 10
arcsector) 13 is provided with teeth 14,
The tooth 14 is engaged by a mating tooth 15 with a pawl (paw+) 160, which is loosely attached by a pin 17 onto the bracket 11 through an elongated slot 18, which slot allows the pawl tooth 15 to Bracket 10
sector 1 at any relative angular position of and 11
3, providing sufficient lost motion for full engagement with adjacent teeth 15 of the pawl.
and sector teeth 14 to provide for the pawl 16 to be approximately centered with respect to the mounting pin 17 and the slot 18.

Cams 19 and 20, which are pivotally mounted on bracket 11 by pins 21 and 22, respectively, provide eccentric cam surfaces 23 and 24, which cam surfaces have angularly related flats on pawl 16. 25 and 26. The cam surfaces 23 and 24 have a full working arc, e.g. 45", and the flat 2 of the pawl
5 and 26 and locking angle
, e.g. 5172'', and the relative position of the single tooth deformation (within 15 brackets) 10 adjusted by the elongated slot 18 allows the fully engaged pawl to be engaged. Positions can be set: flats 25 and 26
The relative angular positions of the cam surfaces 23 and 24, which have reached the position of engagement with the cam surfaces 23 and 24, may be within the pinch of a single tooth adjusted by the elongated slot 18, within any of the central positions shown in FIG. It will be appreciated that this will vary with the displacement of the claws on the sides.

Assuming that the centrally located pawl 16 achieves sufficient engagement with the sector 13 prior to each cam-to-pawl engagement, the fixed angle provided by the cam engagement will will effectively hold the pawl 16 against displacement in either direction due to the pressure of the teeth in the sectors that are Provides effective fixation for

Effective continuously variable adjustment requires that pawl teeth 15 and sector teeth 14 fully engage prior to engagement of any cam surface with its associated pawl surface, and that the teeth also It will be further understood that engagement with sector 13 requires the pawl 16 to be located approximately centrally as described above. A suitable procedure for positioning the pawl prior to cam engagement and for pre-centering the pawl for initial tooth engagement is provided by a link 27 actuated by a pin 28. It projects from an extension 29 of a release handle 30 which is pivotally attached to the bracket 11 at 21 . Upon clockwise actuation of the handle 30, the extension 2
Through the engagement of the surface 31 of 9 with the pins 32 and 33 projecting from the cams 19 and 20, such a handle can
The claw 16 resists the retaining bias (force) of the tension spring 34 connecting the arm extensions 35 and 36 of the cams 19 and 20.
It is suitable for releasing the cam engagement with. Link 27 by handle 30 to the limit of slot 37 with respect to pin 38 projecting into slot 37 from the plane of pawl 16
The linear displacement of provides a positive disengagement of the pawl and the sector against the deflection of a tension spring, which is fixed to the axial projection 40 on the back side of the bracket 11;
The other end of the spring is connected to an extension of the pin 38 of the pawl 16 projecting through a triangular slot 41 in the bracket II. Such release engagement of pin 38 by the end of slot 37
-g6men t) occurs after the releasing movement of both cam surfaces 25 and 26 under the engagement tip of either cam surface and by the engagement of pin 38 with the matching exact end 42 of slot 41. Center the pawl with respect to slot 18. The ends of the camming movement are indicated in the case of the cam arm 19 by arcs extending 15' and 306, respectively, on either side of the neutral line 43 corresponding to the neutral position of the pawl as shown.

The return stroke (retu) of the handle 30 in the counterclockwise direction
rn travel), the same linkage causes the pawl 16 to center under the tension of the spring 39 on the pin 38, and the cam surface 23 for engagement with the flats 25 and 26 of the pawl. and 24 before engaging the teeth 14 of the sector 13 with the teeth 15 of the pawl, which causes the pawl not to move from the predetermined position in which the teeth are fully engaged; The precise continuously adjustable position of the seat bracket 10 is advantageous during initial pawl engagement.

A suitable tooth profile is illustrated in FIG.
It has a pitch of 21/2' and a sharp tooth profile, which provides sufficient protection against point engagement of relative pawl and sector teeth. , the tip engagement prevents the pawl from fully engaging the teeth for effective positioning of the sector.

[The selective manufacturing method of good blanking J (fine blanking) requires a small point radius.
Fine blank with good radius
sector and pawl teeth are not suitable for such sharp teeth, as is required in cutting die. Such a radius increases the likelihood of relative tip engagement of the pawl teeth and sector teeth such as interfering with adequate tooth retention.

Referring to FIG. 2, relative tooth tip interengagement (popint inter-enga-
Optional modifications may be integrated to ensure lateral movement of the pawls from the position of t) and provide good punching by the selective manufacturing method with hinged mounting of the present invention. . A small pin 50 protrudes from the face of the pawl to effect lateral movement of the pawl in case tip interengagement prevents full engagement. End tip 5 of arm extension 52.
1, the extension reaches a position relatively proximate at the moment of initial tip engagement of the pawl and sector teeth during the return stroke of the pawl and actuating handle.

If the pawl teeth enter enough of the side stops on either side of the sector to create a sufficient cam, the arm extension will not engage the pin during the cam return to the seated position. However, if full pawl engagement is prevented by the engagement of the tooth tips in a row, then the extension end 51 will engage the pin 50 and the pin 50 will pass downwardly; is the retention engagement of cams 19 and 20.
movement) to the left in the horizontal direction.

Since at the time of initial tooth retention the pawl and handle extension always reach the same relationship, the pin 50 is always in an effective position relative to the point 51 to perform its function if required. .

Referring to FIG. 4, the test unit's adjustable positioning elements include a sandwiched lower bracket plate 56 (one removed for clarity).
A cord run L with a toothed sector 54 centered on an axis 55 extending between
; quadrant) 53, toothed slide claw (slide
pawl) 51, with two cams 58 each pivoted at 59 between the lower brackets 56. In FIG. 4, the cam 58 and the pawl 57 are illustrated in solid lines in the neutral position and in dashed lines for the case when the pawl 57 is moved to one end;
In the figure, pawl 57 and cam 58 are again illustrated in solid lines, with dashed lines illustrating the pawl moved to the opposite end. The total range of motion of pawl 57 is on the order of 36;
Adjust the cordrant 53 indefinitely with a tooth spacing of 21/2°. The pawl 57 is provided with a circular arc, which has a curvature in the area of contact with the cam 58.
e), the curvature occurring over a very limited band throughout a sufficient range of accommodation.

The approximately 120° rise of the cam illustrated is 0
．． 07 and occurs as a spline curve of substantially constant fixed angle slope with respect to the line extending from the camshaft to the point of contact with the pawl. The can rise of the cam is arranged to provide a minimum dimension relative to the axial center at the other end and a maximum dimension at the upper end, so that
The tendency of pawl 57 to be lifted out of engagement with the sector teeth tends to rotate both cams to a position higher than the other point of engagement and is used in the embodiment of FIGS. 1 and 2. It must be noted that the same is true for opposite cam curves. It has been found in experimental tests that the cam curves of FIGS. 4 and 5 are most effective against the tendency of the cam surface to creep during repeated cycles of high seatback loads.

As will be explained below with reference to FIG. 10, the curvature of the cam and pawl in the contact area, which is about 6, minimizes any deviation from the optimal shape of the force vector.

The test components illustrated in Figures 4-9 were developed to meet the requirements for non-specific seat back adjusters. As with the specific examples of parts that have undergone cyclic torque loading tests, the parts of Figures 6-9 are dimensioned in millimeters, and the parts are well set in critical geometric relationships. As well as additional design details, the bracket 56 is
Constructed of 151101B steel 4.5 mm thick; 4172 mm thick 5AE1020 codranoto heat treated KNO36240 and Rockwell C38-
with a pawl of 4 mm thick Al5I4130 steel quenched and tempered to 48; and a cam of 4 mm thick A1 314130 steel quenched and tempered to Rockwell C3B-45; It is configured.

Referring to FIG. 10, the geometry of force derived from the position of the camshaft can be understood by the following analysis. The appropriate number of pawl teeth is determined in conjunction with the shear stress occurring for maximum torque loading, in this case with a pressure-angle of 14°45', together with an appropriate number for pawl stability.
) and low teeth as shown with a spacing of 2 1/2' (
It is determined that there should be 10 claw teeth formed on the stub l0oth). The determination of the center point of the tooth load 60 is determined by the sum of the force vectors 61 and 62, each with a tangential torque load at the center point of the tooth load and a radial component with a pressure angle of 14° 45'. A line 63 is set, and the composite line passes near the center of curvature 64 for the arc of the claw at the point of contact.

In order to neutralize any torque applied to the cam, the optimum center of the cam curve is located near the extension line of 63, and the claws that tend to occur due to the sum of the loads on the individual teeth are To provide a bias to counteract the tendency to separate, an additional 2" angle 65 is provided, the 2a angle passing through the cam center of curvature located at 66. line and the line passing through the center of curvature of the pawl, such that in addition to the deflection, any tendency to lift the pawl will tend to rotate the cam to a higher raised position; This additionally resists any displacement of the pawl from the state in which the sector tooth and pawl are in full contact.

Based on the convex curvature of the pawl and cam at the point of contact, a single tooth displacement of 21/2'' on the pawl over a range of installation positions for adjusting non-specific adjustments can be made such as between points 67 A very narrow contact zone will be created on the pawl, which will minimize any deviation from the optimum shape with respect to the camshaft over the entire range of adjustment.

With the dimensions and geometry described above, tests have shown that this tendency does not exist for pawl displacement or cam creep under repeated maximum torque loads even when the unloaded cams are released from contact. Ta.

Referring to the assembly of FIG. 3, the modified pawl 57a and cam 58a have been adapted for shorter arcs of cam transition and release, and the kitker mechanism (ktcker mechanism) has been adapted for shorter arcs of cam transition and release.
mechanism). Pawl 57a and cam 58a are shown in a neutral position.

Two cam actuated links 67 and a kicker
The actuating link 6 is driven by a bin 69 at the end of each elongated opening, which bin is connected to a manual release lever 70.
The release lever 70 is located at the end of the 71
It is pivoted at and can be manually moved to the dotted line position 72. They successively release the cam 58a and then actuate the kicker 73, which is pivoted at 59, and engages the pawl pin 74 to disengage it from the cam of the tooth and release the semi-piercing protrusion. (semi-p
ierceprojection) 75 and installed toward the semi-pierced projection 75.
This causes the claw 57a to move to the left within the limits of 6.

The downward movement of the link 68 engaging the kit carbine 77 overcomes the torque spring 78, which biases the biasing bin 79 of the link 67 in the direction in which the cam engages and reactively forces the kit carbine 73 counterclockwise; likewise overcoming torque spring 80, which biases cam pin 81 in the direction of cam engagement and biases pawl pin 74 in the direction of tooth engagement. .

Thus, upon moving the hand lever arm 70 from its released position 72, the pawl pin 74 will be raised towards engagement of the sector teeth by the engaged end of the torque spring 80, and and upon any abutment of the ends of the respective flat teeth of the sector, the kicker 73
curvature surface 82 will move pawl 57a to the right until sufficient tooth engagement occurs so that pawl 57a is in its adjusted position before cam 58a returns to its respective engaged position. It will be fully engaged at .

The cam 58 in FIGS. 4, 5, and 9 is one of the cam curves based on a friction coefficient of 0.07 for normal lubricating grease.
Illustrated with a 20h arc, Monsanto under the trademark [Santotrac]
Chemical Company (Monsanto Che-m)
Special high traction lubricants such as those manufactured by Cow+Pany
1 publica) provides a higher and more efficient frictional engagement of the order of 0.12, and the coefficient is about 70', yielding curves similar to those illustrated in FIGS. 4 and 5.
It is allowed to reduce the cam arc to . Such a shorter arc is used in the release mechanism of FIG.
It is used to move the pin 79 of No. 7 between the limit ends engaged by the cam 84 and to move the link pin 81 between the limit ends 85. A further transition of the link 67, e.g. positioning the pin 79 further to the end 86 in order to m-thread the movement of the kicker 73 by the link 68, will cause the pin 79 to move from the position 87 at the bottom of the slot position 88 at the limit of the release transition 72. This is possible when moving the working bin 69.

The curved portion surface 83 extends sufficiently to allow completion of initial tooth penetration without preventing engagement of the ends of the pawl and sector teeth; however, such engagement causes a rightward movement of the pawl 57a brought about by the curved portion 83, until a sufficient engagement is achieved.

Slots 82 in upper bracket plate 56a limit the lateral movement of pawl pin 74, thereby limiting the overall movement of pawl 57a to approximately 3'', which approximately 36 provides sufficient tooth spacing of 2172°. Satisfied.

From the foregoing description of various embodiments, it can be seen that the present invention provides continuous variable adjustment of a journalled toothed sector.
It will be appreciated that various special devices may be included to achieve secure locking of the toothed pawl. Such structures are particularly useful for seat recliner hinges.
cliner hinge) can be adapted to the application of
Seat back adjustment for rapid release and precise desired positioning and secure fixation, with the proven strength benefits of a toothed pawl and sector system, but with limited increases Without the traditional drawbacks of regulators.

[Brief explanation of the drawing]

1 is a side view of a hinge assembly illustrating one preferred embodiment of the invention; FIG. 2 is a cutaway view of a variation of the hinge attachment portion of FIG. 1; FIG. 4 is a side view of a seat hinge assembly illustrating a preferred embodiment of the invention; FIG. FIG. 5 is a side view of the test unit illustrating the displacement of the claw to the other end due to the neutral position;
Figure 6 is a detailed view of the toothed sector electric cord lant; Figure 7 is a detailed view of the lower bracket plate; Figure 8 is a detailed view of the toothed sector electrical connector; Figure 9 is a detailed view of the slide; Figure 9 is a detailed view of the cam used in the test unit; Figure 10 is an enlarged diagram illustrating the force (vector) conditions of the pawl, toothed sector and cam of the test unit; It is an explanatory diagram. 10... Upper hinge bracket, 11... Lower hinge bracket, 13.54... Sector, 14.15... Teeth, 16
．． 57.57a...Claw, 18.37.41...Slot, 19.20.58.58a...Cam, 27.67.6
B...Link, 30...Handle, 34.39.7
8.80... Spring, 43... Neutral line, 5
3... Cordrant, 56.56a... Bracket plate, 64... Center of curvature, 70... Lever, FIG, 6 Procedural amendment (advanced) May 4, 1985 Commissioner of the Japan Patent Office Shiga Gakuden 1″′″fJ@77< Patent Application No. 60-68618 2,
Q'g117) fslj , -1, . 3. Relationship with the case of the person making the amendment Patent applicant name Caper Rikaguchi Inc. 4.
agent

Claims (1)

Claims: (11) An assembly of pivotally connected elements characterized by a continuously variable adjustment device fixing the relative angular relationship of the pivotally connected elements; a toothed device and a matching interengagable toothed device on the other of said elements, and complete retention of said respective toothed device during adjustment of said relative angular relationship. an attachment device for adjusting release, said attachment device providing fully matched tooth retention of said respective toothed device for any continuously variable adjustable angular relationship of said elements. of said respective toothed device for fixing said respective toothed device against any relative displacement in said relative angular relationship of said elements; a cam device, characterized in that it includes a cam device which is lockable after establishing a sufficient mating engagement; (2) individually engaging one angularly related surface of said toothed device; An assembly as claimed in claim 1, comprising two individually positionable cam surfaces of the cam device which are able to fit together, counteracting relative displacement of the element from tooth pressure in each angular direction. (3) Each movement of said two camming surfaces comprises a reactive mounting on one of said elements for adjusting independent engagement of said angularly related surfaces. (4) Each of the two cam surfaces is configured to frictionally adjust the cam surface engagement angle associated with the pivot mount with the pivot mount throughout the range of cam engagement. 3. An assembly according to claim 3, comprising: (5) said attachment device for adjusting sufficient mating tooth retention adjusting the pitch displacement of a single tooth; An assembly as claimed in claim 1, comprising a motion connection sufficient to provide a motion connection.(6) One of said toothed devices includes a toothed pawl with a motion attachment from said toothed device. An assembly according to claim 5. (7) An assembly according to claim 6, comprising a device for centering said wind in relation to said free movement during initiation of tooth retention. (8) An assembly according to claim 1, wherein one of the elements comprises a toothed sector having a center of an arch coincident with the pivoted connection. (9) One of said toothed devices includes a pawl having a movement connection with said other of said elements and engageable with said toothed sector, said wind being connected to said cam device. 9. An assembly according to claim 8, wherein the assembly is fixed in an adjusted position by. 2. The assembly of claim 1, wherein the pivotally connected element includes a hinge bracket member. An assembly according to claim 1, wherein the pivotally connected element includes a hinge bracket member adapted for use as an adjustable seat back hinge. (2) a manually actuated handle device adapted to actuate said cam device to a release position for effective adjustment; and a resilient device to hold said cam device in a locked position upon manual release of said handle. Claim 11 comprising
Assemblies described in Section. 13. The assembly of claim 12, comprising two individually pivoted cam devices responsive to a single handle actuation. (14) Following disengagement of the cam device, the handle is actuated to disengage the wind and sufficiently maintain engagement of the pawl before re-engaging the cam device; 10. An assembly according to claim 9, comprising a resilient linkage. a9 An assembly according to claim 9, comprising a device for centering the wind for re-engaging in any adjustment position of the sector within the movement limits of the wind connection. Three-dimensional. ao as claimed in claim 1, comprising a device for producing a relative lateral displacement of the teeth in the event that preliminary engagement of the tips of the respective teeth prevents sufficient tooth retention; assembly. 07) Claim comprising a device for effecting lateral movement of said pawl in the event that preliminary tip engagement of the teeth in line with said wind and sector teeth prevents full tooth engagement. An assembly according to scope 9. OI - removing the wind from a centered position if the tip engagement of the relative teeth in the row prevents the wind and sector teeth from fully re-engaging in the adjusted position; 16. An assembly according to claim 15, comprising a laterally displacing device. agl said last device comprises a protrusion on said pawl which is retainable by an extension of said handle when said wind and sector teeth are prevented from re-engaging in said adjusted position; said protrusion and said extension each have sharp corners that are interengagable when said wind and sector teeth are prevented from re-engaging in said adjusted position; and wherein the gap back of each of the sharp corners provides a sharp line of demarcation between the engaging and bypassing relationships of the respective sharp corners.
Assemblies described in Section. (21) The device for centralizing the wind includes a claw bin protruding into an opening having a centrally located corner, and a claw bin projecting into an opening having a centrally located corner, and a claw bin projecting into an opening having a centrally located corner, and a claw bin projecting into an opening having a centrally located corner; 16. An assembly according to claim 15, including a device for moving a bin. (22) Two individually pivotally supported cam devices;
a pawl device lockable by two cam devices, the resilient device for retaining the cam device in the locked position biasing each of the two cam devices into a position on each of the two cam devices; 13. An assembly as claimed in claim 12 with individual torque springs. (23) The movement mount and centering device comprises a pawl pin projecting into the mount opening, and a resilient device within the opening biases the pawl toward the centrally engaged position. 8. An assembly as claimed in claim 7, wherein said pin is actuated to actuate said pin. 24. The toothed sector of claim 8, wherein the toothed sector is convex and the other toothed device includes a pawl having a concave arc with matching teeth. assembly. 25. The assembly of claim 2, wherein the angularly related surfaces include an outer surface of a toothed pawl. 26. The assembly of claim 2, wherein the two cam surfaces include surfaces of each individual cam element pivotally mounted on spaced apart axles. (27) a pivotally connected seat and seat back bracket, a toothed sector on one of said brackets, and holding said toothed sector in adjusted relationship with respect to the other of said brackets; an adjustable seat back hinge comprising a pawl with teeth that engage the sector; and a means for releasably positioning the pawl in fixed and controlled engagement with the sector; a device for attaching said pawl so as to be sufficiently free to adjust its transition into position with respect to, angularly related surfaces on said pawl and any unspecified adjustable relative angle of said placket; also with two individually positionable cam surfaces individually engageable with the angularly related surfaces to resist displacement of the pawl from its position of initial engagement with the sector. a pair of cams separately pivotally mounted on the bracket and continuing to move the pawl into initial engagement with the sector at any given adjusted relative position of the bracket; and then moving the cam into engagement with the pawl. (28) The hinge of claim 27, comprising a low-tooth profile for the sector and pawl teeth. 29. The hinge of claim 28, wherein the tooth profile provides a pressure angle on the order of +4 3/4". A hinge according to Scope No. 29. (31) The contact between the cam and the pawl consists of tangential tooth loading and radial loading with the tooth pressure angle at the effective center of the accumulated pawl tooth loading. A hinge according to claim 30, which occurs on a line corresponding to the resultant force. (32) A convex curvature is provided on the contact surfaces of both the pawl and the cam. The hinge according to (33) having a convex cam contact area in the resultant line of force on the pawl caused by tangential torque loading and tooth pressure for angular hinge displacement loading in either direction. 33. A hinge as claimed in claim 32, comprising a pawl configured as a single tooth slide with corners.