TW202231528A - Insert undercut - Google Patents

Abstract

An insert undercut is disclosed. The insert is metallic and has a first coefficient of thermal expansion (CTE), the insert comprising an outer wall of a first retaining feature; and an undercut shape formed exterior to the outer wall of the first retaining feature such that there is a groove between the outer wall of the first retaining feature and the undercut shape. A composite component having a second CTE different from the first CTE, wherein the insert including the groove is at least partially within the composite component when the composite component is being formed, such that the difference in the first CTE and the second CTE causes the groove between the outer wall of the first retaining feature and the undercut shape of the insert to contract about the composite component to provide a compression to a portion of the composite component within the groove.

Description

Insert undercut

This application claims priority to co-pending US Provisional Patent Application No. 63/116,614, filed by Fraser Andrew on November 20, 2020, entitled "Undercut Inserts" and assigned to the assignee of the present application rights and interests, the entire disclosure of this US Provisional Patent Application is hereby incorporated by reference.

Embodiments of the present invention generally relate to bicycle components, such as crank arms, and methods for making bicycle components.

Typically, metal barrel inserts are co-cured into composite arms with features that transfer torque and other loads from one material to another. Metal inserts are used in carbon products to provide a stronger joint for threaded or splined components. Mechanical features are often used to transfer torque and other loads from one material to another. Composite and metallic materials typically have different coefficients of thermal expansion (CTE). Typically, composites have a lower CTE than metal inserts because the composite needs to be cured around the metal insert, which expands before and during curing of the composite, at a temperature higher than room temperature, or typically service conditions. The part is then cooled after curing or molding. Composite arms/bodies generally do not change size, but all sizes of metal inserts tend to be smaller. The amount depends on the CTE of the metal insert for the particular material. This change in temperature causes the different materials to change size. Typically, the composite material retains its original shape, while the metal insert shrinks to a smaller size. This shrinkage occurs uniformly across all dimensions of the metal insert. When the insert shrinks, this creates stress at the junction between the composite and the metal. Depending on the bonding at the joint, the insert may be completely separated from the composite body. If the insert is not separated from the composite, there will be residual stress at this joint. Both of these conditions will make the part weaker and unable to withstand high external loads (such as pedal loads) when in use.

100: Crank Arm

100a: Right hand drive side crank arm

100b: Left crank arm

102: Ontology

104: Spindle insert

106: Pedal Insert

108: Axis

11: Bottom bracket shaft

110: First end

112: Second end

114, 116: Holes

114a: Spindle keeps shape

116a, 416: Internal retention features

118,120: Insert axis

12: Pivot point

13: Crank assembly

15: Rear axle

17: Chain Tensioner

18: Rear sprocket

19: Chain

202, 202a, 302: Undercuts

202b: Raised

202t: Teeth

222: Bottom bracket

24: Frame

26: Swing arm

28: Front Wheel

30: rear wheel

31: Crown

310, 312: Keep Feature Cuts

32: Seat

33: Seatpost

34: Front fork assembly

36: Handlebar Assembly

36a, 36b: Bottom bracket housing

38: Rear shock absorber components

404, 406: Additional rugged features

414: Pull Department

50: Bike

80: Left hand non-drive side crank assembly

81: Spindle

82: Spindle joint

85: Shaft

90: Right hand drive side crank assembly

91: Chainring

92: Opening

Aspects of the invention are shown by way of example and not by way of limitation in the drawings, in which:

1 is a perspective view of a bicycle according to an embodiment;

2 is an exploded view of a crank assembly according to an embodiment.

3A is a perspective view of an example of a crank arm with an insert, according to an embodiment.

3B is a cross-sectional view of an example of a crank arm with an insert, according to an embodiment.

4A is a perspective view of an example of a spindle insert for a crank arm according to an embodiment.

4B is a cross-sectional view of an example of a spindle insert for a crank arm, according to an embodiment.

4C is a cross-sectional view of a spindle insert in a portion of a crank arm body, according to an embodiment.

5A is a perspective view of an example of a pedal insert for a crank arm according to an embodiment.

5B is a cross-sectional view of an example of a pedal insert for a crank arm, according to an embodiment.

5C is a cross-sectional view of a pedal insert in a portion of a crank arm body, according to an embodiment.

6A is a cross-sectional view of an insert with an angled undercut in a portion of a crank arm body, according to an embodiment.

6B is a cross-sectional view of an insert having one or more protrusions thereon in a portion of a crank arm body, according to an embodiment.

6C is a cross-sectional view of an insert having one or more teeth thereon in a portion of a crank arm body, according to an embodiment.

7 is a cross-sectional view of a pedal insert having one or more protrusions thereon, according to an embodiment.

8 is a cross-sectional view of an insert with two undercuts, according to an embodiment.

9 is a top view of an insert with additional retention feature cutouts, according to an embodiment.

10 is an illustration of an insert with additional retention feature cutouts of different geometries according to an embodiment Top view.

11 is a top view of a spindle insert with additional robustness features, according to an embodiment.

12 is a top view of a pedal insert with additional robustness features, according to an embodiment.

Unless otherwise indicated, the drawings referred to in this specification should be understood to be not drawn to scale.

The detailed description set forth below in connection with the drawings is intended as a description of various embodiments of the present invention and is not intended to represent the only embodiments in which the invention may be practiced. Each embodiment described in this disclosure is provided merely as an example or illustration of the invention and should not be construed as preferred or advantageous over other embodiments. In some instances, well-known methods, procedures, articles and circuits have not been described in detail so as not to unnecessarily obscure aspects of the present disclosure.

The difference in thermal expansion properties between composite and metal parts is often referred to as differential thermal expansion. When the composite material is molded around a cylindrical metal insert at high temperature, the metal insert takes on a larger shape under thermal conditions in order to cure the resin. The whole part is then cooled and the metal part shrinks into a smaller shape, while the composite material (which has a different coefficient of thermal expansion) tends to keep the larger shape or close to the hot shape (the composite material changes less in shape due to temperature) ). Based on these differences in thermal expansion properties, during cooling, the metal part will try to shrink and separate from the composite material, which results in large stresses at the bond between the composite material and the metal part, leading to bond failure. This failure may even occur before design/external loads are applied.

The embodiments disclosed herein provide a number of shape and retention features within the insert, thereby increasing the strength of the joint using the different coefficients of thermal expansion of the two materials, rather than compromising the strength of the joint.

One embodiment utilizes a hook or undercut shape feature on the insert that will provide at least one surface that will attempt to compress the composite after the part cools from solidification. The shape of the metal insert is designed so that some of the composite material effectively sits within (or around) a portion of the metal insert, so the composite material is compressed by the insert as the structure cools.

[00010] In one embodiment, the insert is partially cylindrical, but also has a portion extending outwardly along the body of the crank to resist torque loads and any other loads encountered. In one embodiment, the design also keeps cross-sectional or acute angle changes to a minimum in the composite, which allows for maximum Make optimal use of the strength of composite materials.

In the following discussion, one or more components are molded together to form an inseparable body. In one embodiment, instead of two inserts, one of the two inserts would not be used and a direct connection could be used for this end of the arm.

In one embodiment, a spindle insert refers to a metal part, typically a forged or machined aluminum alloy, titanium alloy, steel, other metal alloys, metals, and the like. The spindle can be received with a spline or an integral spindle can be used. An embodiment may also have other features on the insert to transfer loads or locate links, bearing preload collars, self-pulling bolt caps.

In one embodiment, pedal inserts refer to metal parts, typically forged or machined aluminum alloys, titanium alloys, steel, other metal alloys, metals, and the like. Typically, the pedal insert will have standard threads to fit the pedal into the pedal insert.

In one embodiment, the spindle insert is partially enclosed at one end of the composite arm. In one embodiment, the pedal insert is partially enclosed at the end of the composite arm opposite the main shaft.

In the following discussion, the composite arm can be a thermoplastic or thermoset matrix with various fiber materials, most typically carbon, glass, or other fibers, in part or alone. The purpose of the composite arm is to transfer the load from the pedal insert to the spindle insert.

Typically, crank arms are used to transmit the force generated by the user's legs on the pedals to the chainrings. The force is transmitted from the pedals to the cranks, and then to the chainrings to finally turn the rear wheel. The crank arms also position the pedals relative to the bike frame, even under harsh loads from obstacles or falls.

In one embodiment, the crank arm typically has a length (between the inserts, eg, between the pedal shaft centerline and the main shaft centerline) of 155mm to 175mm. In one embodiment, the pedal insert will fit within a box volume (L x W x H) of 50mm x 30mm x 20mm, and the spindle insert will have a volume of 70mm x 50mm x 30mm. While various lengths, dimensions, measurements and volumes are provided, these are provided as examples of one implementation. It should be understood that the present technology may utilize one or more of different lengths, dimensions, measurements and volumes.

In the following discussion, and for clarity, a bicycle is used as an example vehicle. However, in another embodiment, the undercut insert may be used on one or more of a variety of vehicles such as, but not limited to, bicycles, electric bicycles (electric vehicles), mopeds, etc. . In one embodiment, the shapes and features of the undercut insert described herein can be used in another composite/metal hybrid part to provide retention features created by the shape of the undercut insert.

Referring now to FIG. 1 , a perspective view of a bicycle 50 according to an embodiment is shown. In one embodiment, the bicycle 50 has a frame 24 with a suspension system, the frame 24 including a swing arm 26 capable of movement relative to the rest of the frame 24 in use; this movement is caused, inter alia, by the rear shock assembly 38 allowed. The front fork assembly 34 also provides suspension functionality via a shock assembly in at least one of the fork legs.

In one embodiment, bicycle 50 is a full suspension bicycle. In another embodiment, the bicycle 50 has only front suspension and no rear suspension (eg, a hardtail). In various embodiments, the bicycle 50 may be a road bicycle, a mountain bike, a gravel bicycle, an electric bicycle (electric vehicle), a hybrid bicycle, a motorcycle, or the like.

In one embodiment, swing arm 26 is pivotally attached to frame 24 at pivot point 12 located above bottom bracket axis 11 . Although the pivot point 12 is shown at a particular location, it should be understood that the pivot point 12 may be found at different distances from the bottom bracket axis 11 depending on the rear suspension configuration. The use of specific pivot points 12 is provided herein for clarity only. Bottom bracket shaft 11 is the center of pedal and crank assembly 13 . Although the pivot point 12 is shown at a particular location, it should be understood that the pivot point 12 may be found at different locations depending on the rear suspension configuration. The use of pivot points 12 is provided herein for clarity only.

For example, in a hardtail bicycle embodiment, there would be no pivot point 12 . In one embodiment of a hardtail bicycle, the frame 24 and swing arms 26 would be formed as a fixed frame.

Bicycle 50 includes front wheel 28 coupled to front fork assembly 34 via axle 85 . In one embodiment, the front fork assembly 34 includes a crown 31 . In one embodiment, a portion of the front fork assembly 34 (eg, the steerer tube) passes through the frame 24 and is coupled with the handlebar assembly 36 . As such, the fork assembly and handlebar are rotationally coupled with the frame 24 , thereby allowing the rider to steer the bicycle 50 .

In one embodiment, the bicycle 50 includes a rear wheel 30 coupled to the swing arm 26 at the rear axle 15 . A rear shock assembly 38 is positioned between the swing arm 26 and the frame 24 to provide resistance to pivotal movement of the swing arm 26 about the pivot point 12 . Thus, the illustrated bicycle 50 includes a position on the swing arm 26 A suspension member with the frame 24 that operates to significantly reduce the impact force transmitted to the rear wheel 30 of the rider of the bicycle 50 .

In one embodiment, bicycle 50 is driven by chain 19 coupled to both crank assembly 13 and rear sprocket 18 . When the rider pedals, the rotational input of the crank arm 100 causes the crank assembly 13 to rotate about the bottom bracket axis 11 . This rotation exerts a force on the chain 19, which transfers the rotational energy generated by the rider to the rear sprocket 18, causing the rear wheel 30 to rotate. The chain tensioner 17 provides a variable amount of tension on the chain 19 . The need for varying lengths of the chain 19 may be due to a number of different gears that may be located on one or both of the crank assembly 13 and/or the rear sprocket 18 and/or on the bottom bracket axle 11 (on the bottom frame axle 11 ). Chain stays change when the distance between the crank assembly 13 attached to the frame 24) and the rear axle 15 changes due to suspension articulation.

In one embodiment, the saddle 32 is connected to the frame 24 via a seat post 33 . In one embodiment, the seatpost 33 is a drop seatpost.

In one embodiment, bicycle 50 may include one or more active suspension components, sensors, etc., such as disclosed in US Pat. No. 10,036,443, which is incorporated herein by reference in its entirety.

Referring now to FIG. 2 , an exploded view of the crank assembly 13 is shown according to an embodiment. In FIG. 2 , the crank assembly 13 is shown integrated with a portion of the bicycle frame 24 . In one embodiment, the bicycle frame 24 includes a bottom bracket housing 36a and a bottom bracket housing 36b.

In one embodiment, the crank assembly 13 includes a left hand non-drive side crank assembly 80 including a left hand crank arm 100b and a main shaft 81 , which in one embodiment includes a main shaft joint 82 .

In one embodiment, the crank assembly 13 includes a right hand drive side crank assembly 90 including a right hand drive side crank arm 100a having a spindle receiving engagement such as a spindle insert 104, a chain having an opening 92 Ring 91 and roller chain 19. In one embodiment, the crank assembly 13 includes additional parts such as pedals, pedal washers, boots, spindle spacers, bearings, hex nuts, and the like. These parts are not shown for clarity.

In one embodiment, the main shaft 81 is coupled with the left hand crank arm 100b, for example, during manufacture, assembly, maintenance, rebuilding, component replacement, etc. of the left hand non-drive side crank assembly 80 . In a In one embodiment, the main shaft 81 is fixedly coupled to the left-hand crank arm 100b during manufacture and/or assembly. In one embodiment, the main shaft 81 and the left hand crank arm 100b are manufactured as a single piece. In one embodiment, the main shaft 81 and the left hand crank arm 100b are two distinct parts that are removably coupled when assembled.

In one embodiment, for example, during manufacture and/or assembly of the right hand drive side crank assembly 90, the chainring 13 is coupled with the right hand drive side crank arm 100a. In one embodiment, the chainring 13 is fixedly coupled to the right hand drive side crank arm 100a during manufacture and/or assembly. In one embodiment, the chainring 13 and the right hand drive side crank arm 100a are manufactured as a single piece. In one embodiment, the chainring 13 and the right hand drive side crank arm 100a are two distinct parts that are removably coupled upon assembly.

In one embodiment, to install crank assembly 13 into frame 24 of bicycle 50 , spindle 81 is inserted through a portion of bicycle frame 24 (including bottom bracket housing 36a and bottom bracket housing 36b ) and an opening in chainring 13 92. The main shaft interface 82 is coupled with the pedal insert 106 on the right hand drive side crank assembly 90 .

During installation of crank assembly 13 into frame 24 , one or more bearings (or the like) will be positioned around main shaft 81 and between bottom bracket 222 and bottom bracket before main shaft 81 is inserted into frame 24 between the housings 36a. Once the main shaft 81 passes through the frame 24, one or more bearings (or the like) will be positioned around the main shaft 81 and between the pedal insert 106 and the bottom bracket housing 36b. In one embodiment, one or more bearings (or the like) allow rotational movement of the main shaft 81 within the frame 24 while also maintaining a fixed and correct orientation of the main shaft 81 within the frame 24 .

In one embodiment, some of the components of crank assembly 13 include materials such as aluminum alloys, titanium alloys, steel, other metal alloys, metals, ceramics, and the like. In one embodiment, some of the components of crank assembly 13 include composite materials, such as composites with thermoset or thermoplastic matrices, long or short fiber thermoplastic or thermoset composites, injection molded carbon fibers, carbon fiber reinforced nylon, carbon fiber reinforced epoxy Resins, glass-filled nylon, compression molding materials, laminates, chopped carbon fibers, plastics, polymers, long fiber reinforced plastics, short fiber reinforced plastics, etc. In one embodiment, one, some, or all of the components of crank assembly 13 may be formed from a combination of these materials components, such as composite/metal hybrids. Crank assemblies can be manufactured by various methods such as compression molding, balloon molding, vacuum molding, resin transfer molding (RTM), wire winding, automated fiber placement (AFP), automated lay-up Belt (Automated Tape Laying, ATL) and so on.

Referring now to FIG. 3A, one example of a crank arm 100 (which is an example of a drive side crank arm 100a or a non-drive side crank arm 100b other than those identified herein) includes a body 102 and a first insert ( For example, spindle insert 104 or pedal insert 106). In one embodiment, crank arm 100 also includes body 102, first and second inserts (eg, spindle insert 104 and pedal insert 106). Although currently shown with two inserts (eg, spindle insert 104 and pedal insert 106 ), crank arm 100 may be configured to include a different number of inserts, including, for example, only one insert, or three or more inserts Multiple inserts (such as a stringer insert or another additional structural insert, etc.).

The body 102 is generally elongate and extends along the body axis 108 between the first end 110 and the second end 112 . In one embodiment, the spindle insert 104 is fixedly coupled with the body 102 and facilitates coupling with the spindle 81, while the pedal insert 106 is fixedly coupled with the body 102 and facilitates coupling with a pedal or pedal assembly.

In one embodiment, the body 102 is formed from a body material, and the spindle insert 104 and pedal insert 106 are formed from an insert material, which may be different from the body material. In one embodiment, the body 102 is formed from a composite material including carbon fibers, and the spindle insert 104 and/or the pedal insert 106 are formed from an aluminum alloy. Alternatively, the body 102 may be formed from any other suitable material, including, for example, composite materials including fiberglass, Kevlar, boron fiber, or beryllium fiber, or including metals or plastics or polymers. Spindle insert 104 and/or pedal insert 106 may be formed from any suitable material having the desired strength to support the rotatable connection between the crank arms and other bicycle components, including, for example, aluminum, steel, titanium, other metals and metal alloys, composites and/or polymers or plastics.

In one embodiment, each of spindle insert 104 and pedal insert 106 includes a central hole or aperture (eg, respective hole 114 and hole 116 ) configured to receive fasteners. Holes 114 and 116 may be threaded or otherwise configured to mate with corresponding fasteners. In a In one embodiment, both the spindle insert 104 and the pedal insert 106 extend along respective insert axis 118 and insert axis 120 .

In one embodiment, the external features of the spindle insert 104 and pedal insert 106 (eg, insert undercuts to maintain the shape) are similar in shape. In one embodiment, the external features of the spindle insert 104 and pedal insert 106 (eg, insert undercut retention shape) differ from each other.

In one embodiment, the internal features of the spindle insert 104 and pedal insert 106 are similar. In one embodiment, the internal features of the spindle insert 104 and the pedal insert 106 differ from each other. For example, in one embodiment, providing inserts that are internally configured differently may help facilitate different types of connections between crank arms 100 , such as the first interior to receive/couple the main shaft 81 The shape of the spindle insert 104, and the pedal insert 106 of a different internal shape (compared to the internal shape of the spindle insert 104) to receive/couple the pedal assembly.

Referring now to FIG. 3B , a cross-sectional view of an example of a crank arm 100 with an insert is shown, according to an embodiment. In FIG. 3B , the cross-section of crank arm 100 includes spindle insert 104 and pedal insert 106 . The features of FIG. 3B are similar to those of FIG. 3A and, therefore, for the sake of clarity, the discussion of the features shown in FIG. 3A is not repeated.

In one embodiment, the crank arm 100 is an elongated "composite body" with a length several times greater than the width or thickness. In one embodiment, the crank arm 100 is made of a thermoset or thermoplastic matrix material and reinforcing fiber material. The center can be hollow or solid. In one embodiment, the crank arm 100 has two cylindrical inserts with parallel axes spaced a set distance apart.

In one embodiment, pedal insert 106 is a metal insert disposed in the composite material used to form crank arm 100 prior to curing, and the composite material is cured around pedal insert 106 to form a single structure. Typically, the pedal insert 106 is used to form a strong joint for attaching the pedal to the pedal insert. In one embodiment, the pedal is screwed into the pedal insert 106 . In one embodiment, the metal pedal insert 106 keeps the threads strong and allows for repeated removal and fitting.

In one embodiment, the spindle insert 104 is a metal insert that is disposed in the composite material used to form the crank arm 100 prior to curing, and the composite material is in the spindle insert 104 Cures around to form a single structure. Typically, the spindle insert 104 is used to form a strong joint to attach the spindle and sometimes the link, which is used to transfer loads from the composite body to the spindle or link. In one embodiment, the spindle insert 104 is typically fabricated from a metal or metal alloy to allow for repeated installation and removal of the spindle and chainring, and to allow threaded fasteners/lockrings to be fitted onto the spindle insert 104 .

Referring now to FIG. 4A , a perspective view of an example of a spindle insert 104 for a crank arm 100 is shown, according to an embodiment. Generally, the spindle insert 104 includes a spindle retaining shape 114a around the bore 114 . To assist in securing the spindle insert 104 within the body 102 , the spindle insert 104 may include one or more undercuts 202 configured to be embedded in and surrounded by the body 102 .

Typically, the undercut 202 (which may be a hook shape or the like) is formed as part of an insert of composite material comprising the body 102 . In one embodiment, as the metal spindle insert 104 and/or pedal insert 106 cools, the undercut 202 will compress onto the composite body 102 rather than pulling away from the composite body 102 . This will create engagement surfaces between the composite body 102 and the spindle insert 104 and/or pedal insert 106 that are compressed together and will resist pulling apart; thereby allowing the bond between the parts to be stronger, and in the event of failure Higher external loads were previously allowed.

In one embodiment, the undercut 202 may be oriented and configured to help prevent rotation of the spindle insert 104 relative to the body 102 about the insert axis 118 (shown in FIG. 3A ) and/or to help prevent spindle insertion The member 104 translates relative to the body 102 along the insert axis 118 . For example, the spindle insert 104 (and similar pedal insert 106 ) would have features extending along the long axis 108 of the crank 100 to provide torsional resistance and resistance to other loads that may be encountered.

4B is a cross-sectional view A-A of an example of a spindle insert 104 for crank arm 100, shown according to an embodiment. In one embodiment, the spindle insert 104 includes a tether 414 (eg, external splines) to locate the chainring 91 , the tether 414 including retention features such as threads, splines, and the like. In one embodiment, the spindle insert 104 includes internal retention features 416 for the locking ring, such as threads or the like. In one embodiment, the spindle insert 104 including the internal retention feature 416 is only necessary for the right hand drive side crank 100a. In one embodiment, the main shaft insert 104 on the non-drive side crank 100b does not require the internal retention feature 416 .

FIG. 4C is a main shaft in a portion of crank arm body 102 according to an embodiment Cross-sectional view A-A of insert 104 .

5A is a perspective view of an example of a pedal insert 106 for a crank arm 100, according to an embodiment. Typically, pedal insert 106 includes a generally cylindrical portion surrounding hole 116 . To aid in securing the pedal insert 106 within the body 102 , the pedal insert 106 may include one or more undercuts 202 configured to be embedded in and surrounded by the body 102 . The undercut 202 may be directionally configured to help prevent rotation of the pedal insert 106 relative to the body 102 about the insert axis 120 (as shown in FIG. Translate along the insert axis 120 .

5B is a cross-sectional view of an example of a pedal insert 106 for the crank arm 100, shown according to an embodiment. In one embodiment, pedal insert 106 includes internal retention features 116a such as threads or the like for coupling the pedal with pedal insert 106 and undercut 202 .

5C is a cross-sectional view of the pedal insert 106 in a portion of the crank arm body 102, shown according to an embodiment. In one embodiment, pedal insert 106 includes internal retention features 116a such as threads or the like for coupling the pedal with pedal insert 106 and undercut 202 to maintain the position of pedal insert 106 relative to body 102 .

6A is a cross-sectional view of the spindle insert 104 and/or pedal insert 106 with an angled undercut 202a in a portion of the crank arm body 102, shown according to an embodiment. In one embodiment, the angled undercut 202a is greater than 90 degrees.

6B is a cross-sectional view of the spindle insert 104 and/or pedal insert 106 having one or more protrusions 202b thereon in a portion of the crank arm body 102, according to an embodiment. 6C is a cross-sectional view of the spindle insert 104 and/or pedal insert 106 having one or more teeth 202t thereon in a portion of the crank arm body 102, according to an embodiment. Typically, features such as protrusions, ridges, teeth, etc. on one or more surfaces of the spindle insert 104 and/or pedal insert 106 enhance the locking of the spindle insert 104 and/or pedal insert 106 with the body 102 . In one embodiment, features such as protrusions, ridges, teeth, etc. extend circumferentially about the spindle insert 104 and/or the pedal insert 106 .

7 is a cross-sectional view of a pedal insert 106 (similar to the pedal insert 106 of FIGS. 5A-5C ) having one or more protrusions 202b thereon, according to an embodiment. in a In embodiments, one or more protrusions 202b (or other features such as ridges, teeth, etc.) extend parallel to the pedal insert 106 axis. Typically, features such as protrusions, ridges, teeth, etc. aid in locking to the composite material after curing and cooling.

8 is a cross-sectional view of the spindle insert 104 and/or pedal insert 106 with two undercuts 202 and 302 (eg, two-sided undercuts), according to an embodiment. In one embodiment, the two side undercuts provide additional locking and are symmetrical in design. In one embodiment, one or both of the undercuts 202 and/or 302 may include additional retention features such as protrusions, ridges, teeth, etc. on one or more surfaces thereof to include the undercuts Either or both of 202 and 302.

9 is a top view of the spindle insert 104 and/or pedal insert 106 with additional retention feature cutouts 310, according to an embodiment. In one embodiment, the retention feature cutout 310 includes one or more grooves (or other geometric designs) to provide additional faces for locking onto. For example, the composite body 102 will be formed or seated in these retention feature cutouts 312, and the composite material will be bonded together through the retention feature cutouts 312 during molding to attach the spindle insert 104 and/or pedal insert 106 to the body 102 locked together.

FIG. 10 is a top view of an insert having additional retention feature cutouts 312 of different geometries shown in accordance with an embodiment. In one embodiment, the retention feature cutout 312 includes one or more rounds (or other geometric designs such as star, oval, oval, etc.) to provide additional faces for locking onto. For example, the composite body 102 will be formed or seated in these retention feature cutouts 312 and the composite material will be joined together through the retention feature cutouts 312 during molding to attach the spindle insert 104 and/or pedal insert 106 to the body 102 locked together.

FIG. 11 is a top view of the spindle insert 104 with additional sturdiness features 404 shown in accordance with an embodiment. In one embodiment, the spindle insert 104 may include one or more retention feature cutouts 310 and/or 312 and/or include additional sturdy features 404 on one or more surfaces of the spindle insert 104 Additional retention features such as protrusions, ridges, teeth, etc. In one embodiment, the additional sturdiness features 404 provide the spindle insert 104 with an additional amount of surface area in contact with the body 102 to provide additional strength properties. In general, additional strength may be important for vehicles such as mountain bikes, gravel bikes, etc. that will experience greater stress on the crank arms 100 . In one embodiment, the size, shape, surface area, undercut, etc. of the additional robust features 406 can vary according to the crank The arm 100 and/or the crank arm 100 is adjusted according to the structural requirements of the vehicle to which the arm 100 and/or crank arm 100 is to be mounted.

FIG. 12 is a top view of the pedal insert 106 with additional sturdy features 406 according to an embodiment. In one embodiment, pedal insert 106 may include one or more retention feature cutouts 310 and/or 312 and alternatively include additional sturdy features 406 on one or more surfaces of spindle insert 104 Retain features such as bumps, ridges, teeth, etc. In one embodiment, the additional sturdiness features 406 provide the pedal insert 106 with an additional amount of surface area in contact with the body 102 to provide additional strength properties. In general, the additional strength may be important for a vehicle such as a mountain bike, gravel bike, etc. that will experience greater stress on the crank arm 100 than another vehicle, such as a road bike. In one embodiment, the size, shape, surface area, undercut, etc. of the additional robust features 406 can be adjusted according to the structural requirements of the crank arm 100 and/or the vehicle to which the crank arm 100 is to be mounted.

The examples set forth herein are presented in order to best explain, describe the particular application and thereby enable those skilled in the art to make and use the described example implementations. However, those skilled in the art will appreciate that the foregoing description and examples have been presented for purposes of illustration and example only. The set forth description is not intended to be exhaustive or to limit the embodiments to the precise form disclosed. Rather, the specific features and acts described above are disclosed as example forms of implementing the claimed scope.

References throughout this document to "one embodiment," "some embodiments," "an embodiment," "various embodiments," "some embodiments," "implementations," or similar terms are meant to incorporate A particular feature, structure, or characteristic described in this embodiment is included in at least one embodiment. Thus, the appearances of these phrases in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics of any embodiment may be combined in any suitable manner with one or more other features, structures or characteristics of one or more other embodiments without limitation.

100a: Right hand drive side crank arm

100b: Left crank arm

104: Spindle insert

13: Crank assembly

19: Chain

24: Frame

36a, 36b: Bottom bracket housing

80: Left hand non-drive side crank assembly

81: Spindle

82: Spindle joint

90: Right hand drive side crank assembly

91: Chainring

92: Opening

Claims (20)

A hybrid assembly comprising: A metal part having a first coefficient of thermal expansion (CTE), the metal part comprising: the outer wall of the first retention feature; and an undercut shape formed on the exterior of the outer wall of the first retention feature such that a groove exists between the outer wall of the first retention feature and the undercut shape; and a composite part having a second coefficient of thermal expansion different from the first coefficient of thermal expansion, wherein, when forming the composite part, the metal including the grooves The component is located at least partially within the composite component such that the difference in the first coefficient of thermal expansion and the second coefficient of thermal expansion results in all of the outer wall of the first retention feature and the metal component being located. The grooves between the undercut shapes shrink around the composite part to provide compression to the portion of the composite part within the grooves. The hybrid assembly of claim 1 wherein the composite component is a base portion of a bicycle crank arm extending along a body axis and having a first body end and a second body end, the The second body end is axially spaced from the first body end. The hybrid assembly of claim 2, wherein the metal component is a spindle insert mounted within the bicycle crank arm at the first body end, the spindle insert extending along an insert axis , the insert axis is substantially orthogonal to the body axis of the bicycle crank arm. The hybrid assembly of claim 2, wherein the metal component is a pedal insert mounted within the bicycle crank arm at the second body end, the pedal insert extending along an insert axis , the insert axis is substantially orthogonal to the body axis of the bicycle crank arm. The hybrid assembly of claim 2, further comprising: The metal component is a spindle insert mounted within the bicycle crank arm at the first body end, the spindle insert extending along an insert axis generally orthogonal to the the body axis of the bicycle crank arm; and a metal pedal insert including a groove between the outer wall of the second retention feature and the undercut shape, the metal pedal insert mounted at the second body end Within the bicycle crank arm, the metal pedal insert extends along an insert axis that is substantially orthogonal to the body axis of the bicycle crank arm, wherein when the composite is formed In the case of a material part, the metal pedal insert including the groove is located at least partially within the composite material part. The hybrid assembly of claim 1, wherein the metal component further comprises: a two-sided undercut shape formed on the exterior of the outer wall of the first retention feature such that between the outer wall of the first retention feature and the two-sided undercut shape There are upper and lower grooves. The hybrid assembly of claim 1, wherein the metal component further comprises: at least one opening formed in a portion of the metal part that is external to the outer wall of the first retention feature, the at least one opening in a portion of the composite part around the metal part The portion is formed to provide an additional face for the composite material to lock into. The hybrid assembly of claim 1, wherein the metal component further comprises: at least one retention feature protruding from a portion of the outer wall of the first retention feature, protruding from the groove or protruding from the undercut shape, the at least one retention feature protruding from the The composite part when formed around the portion of the metal part provides an additional face for the composite to lock into. A bicycle crank arm assembly, comprising: A metal part having a first coefficient of thermal expansion (CTE), the metal part comprising: the outer wall of the first retention feature; and an undercut shape formed on the exterior of the outer wall of the first retention feature such that a groove exists between the outer wall of the first retention feature and the undercut shape; and A composite crank arm having a second coefficient of thermal expansion different from the first coefficient of thermal expansion, wherein when the composite crank arm is formed, the groove including the groove The metal component is located at least partially within the composite crank arm such that all The difference in the first coefficient of thermal expansion and the second coefficient of thermal expansion causes the groove between the outer wall of the first retention feature and the undercut shape of the metal part to wrap around the compound The material crank arm contracts to provide compression to the portion of the composite crank arm within the groove. The bicycle crank arm assembly of claim 9, wherein the composite crank arm comprises: A base portion extending along the body axis and having a first body end and a second body end, the second body end being axially spaced from the first body end. The bicycle crank arm assembly of claim 10, wherein the metal component is a spindle insert mounted within the composite crank arm at the first body end, the spindle insert along the insert A member axis extends, the insert member axis being substantially orthogonal to the body axis of the composite crank arm. The bicycle crank arm assembly of claim 10, wherein the metal component is a pedal insert mounted within the composite crank arm at the second body end, the pedal insert along the insert A member axis extends, the insert member axis being substantially orthogonal to the body axis of the composite crank arm. The bicycle crank arm assembly of claim 10, further comprising: The metal component is a spindle insert mounted within the composite crank arm at the first body end, the spindle insert extending along an insert axis that is substantially orthogonal to the the body axis of the composite crank arm; and a metal pedal insert including a groove between the outer wall of the second retention feature and the undercut shape, the metal pedal insert mounted at the second body end Within the composite crank arm, the metal pedal insert extends along an insert axis that is substantially orthogonal to the body axis of the composite crank arm, wherein when forming the When the composite crank arm is used, the metal pedal insert including the groove is located at least partially within the composite crank arm. The bicycle crank arm assembly of claim 9, wherein the metal part further comprises: a two-sided undercut shape formed on the outer wall of the first retention feature Externally, such that there are upper and lower grooves between the outer wall of the first retention feature and the two side undercut shapes. The bicycle crank arm assembly of claim 9, wherein the metal part further comprises: at least one opening formed in a portion of the metal part that is external to the outer wall of the first retention feature, the at least one opening around the metal part in the composite crank arm The portion of the composite crank arm is formed to provide an additional face into which the composite crank arm locks. The bicycle crank arm assembly of claim 9, wherein the metal part further comprises: at least one retention feature protruding from a portion of the outer wall of the first retention feature, protruding from the groove or protruding from the undercut shape, the at least one retention feature protruding from the The composite crank arm, when formed around the portion of the metal component, provides an additional face for the composite crank arm to lock into. A bicycle crank arm assembly, comprising: A plurality of metal components, the plurality of metal components having a first coefficient of thermal expansion (CTE), each metal component of the plurality of metal components comprising: retaining the outer walls of the feature; and an undercut shape formed on the exterior of the outer wall of the retention feature such that There must be a groove between the outer wall of the retention feature and the undercut shape; and A composite crank arm having a second coefficient of thermal expansion different from the first coefficient of thermal expansion, the composite crank arm comprising: a base portion extending along a body axis and having a first body end and a second body end, the second body end being axially spaced from the first body end, wherein when formed In the composite crank arm, each metal part of the plurality of the metal parts including the groove is located at least partially within the composite crank arm such that the first coefficient of thermal expansion is the same as the The difference in the second coefficient of thermal expansion causes each of the grooves located between the outer wall of the retention feature and the undercut shapes of the plurality of metal components to crank around the composite material arm retraction to provide compression to the portion of the composite crank arm located within each of the grooves. The bicycle crank arm assembly of claim 17, further comprising: At least one of the plurality of metal components is a spindle insert mounted within the composite crank arm at the first body end, the spindle insert extending along an insert axis, the an insert axis substantially orthogonal to the body axis of the composite crank arm; and At least one of the plurality of metal components is a pedal insert mounted within the composite crank arm at the second body end, the pedal insert extending along an insert axis, the The insert axis is generally orthogonal to the body axis of the composite crank arm. The bicycle crank arm assembly of claim 17, wherein at least one metal component of the plurality of metal components further comprises: A two-sided undercut shape formed on the exterior of the outer wall of the retention feature such that there is an upper groove between the outer wall of the retention feature and the two-sided undercut shape and lower grooves. The bicycle crank arm assembly of claim 17, wherein at least one metal component of the plurality of metal components further comprises: at least one opening formed in a portion of at least one of the plurality of metal components that is external to the outer wall of the retention feature, the at least one opening forming the providing an additional face into which the composite crank arm locks when the composite crank arm is present; and at least one retention feature protruding from a portion of the outer wall of the retention feature, protruding from the groove or protruding from the undercut shape, the at least one retention feature in the composite material The crank arm, when formed around the portion of the metal component, provides an additional face for the composite crank arm to lock into.

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