United States Court of Appeals 

for the Federal Circuit ______________________ 

IN RE LUTZ BIEDERMANN AND JURGEN HARMS

______________________ 

2013-1080

______________________ 

Appeal from the United States Patent and Trademark 

Office, Patent Trial and Appeal Board in Application No. 

10/306,057.

______________________ 

Decided: October 18, 2013

______________________ 

LUKE DAUCHOT, Kirkland & Ellis, LLP, of Los Angeles, California, argued for appellant. With him on the 

brief were NIMALKA R. WICKRAMASEKERA and BENJAMIN 

A. HERBERT. Of counsel on the brief was MARK GARSCIA, 

Christie, Parker & Hale, LLP, of Glendale, California. 

MONICA B. LATEEF, Associate Solicitor, United States 

Patent and Trademark Office, of Alexandria, Virginia, 

argued for appellee. With her on the brief were NATHAN 

K. KELLEY, Deputy Solicitor, and AMY J. NELSON, Associate Solicitor. 

______________________ 

Before MOORE, LINN, and O’MALLEY, Circuit Judges.
2 IN RE LUTZ BIEDERMANN

LINN, Circuit Judge.

Lutz Biedermann and Jurgen Harms (collectively 

“Biedermann”) appeal a decision of the Board of Patent 

Appeals and Interferences (“Board”), now the Patent Trial 

and Appeal Board, affirming the rejection of claims 32, 33, 

35–37 37, 39, and 48 of U.S. Patent Application No. 

10/306,057 (“’057 Application”) for obviousness, 35 U.S.C. 

§ 103(a). Ex parte Biedermann, No. 2010-006113, Application No. 10/306,057, 2012 WL 3561836 (B.P.A.I. Aug. 

16, 2012) (Decision on Request for Rehearing) (“Decision 

on Rehearing”); Ex parte Biedermann, No. 2010-006113, 

Application No. 10/306,057, 2012 WL 1979400 (B.P.A.I.

May 30, 2012) (Decision on Appeal) (“Decision on Appeal”). Because the Board issued new grounds of rejection, this court vacates and remands for further 

proceedings.

I. BACKGROUND

A. The Patent Application

The invention in the ’057 Application, shown in the 

below reproduced Figure 1, is generally directed to a bone 

screw with a shank (1) and a holding portion with a Ushaped cross-section (2) for a rod (100) that connects to 

other bone screws. The two legs of the holding portion (4 

and 5) have an inner thread (7) that cooperates with the

outer thread (8) of a locking element or screw (9) to hold 

the rod securely in place. The two flat flanks of the inner 

thread are at a 90 ̊ angle to the central axis of the holding 

portion. This results in the thread having a substantially 

rectangular cross-section. The flanks of the outer thread 

of the locking element are likewise at a 90 ̊ angle to the 

central axis of the locking element. These threads are 

sometimes referred to as square threads. The crest of the 

outer thread on the locking element is spaced from the 

root of the inner thread on the holding portion. The ’057 
IN RE LUTZ BIEDERMANN 3

Application describes these 90 ̊-oriented flat threads as 

advantageously obviating the generation of outward 

radial forces. This avoids splaying of the holding portion’s 

legs and eliminates the need for an additional element 

applied to the outside of the legs to avoid splaying. The

application also describes these threads as advantageous 

because they are easy to produce. 

Representative Claim 32 of the ’057 Application recites: 

32. A holding device comprising:

a shank portion;

a holding portion connected to the shank portion for holding a rod; and
4 IN RE LUTZ BIEDERMANN

a locking element to lock the rod in the holding portion;

wherein the holding portion comprises a recess on one end having a U-shaped cross-section 

and two open legs for receiving the rod, and an 

inner thread on the open legs;

wherein the locking element comprises an 

outer thread having two flanks, the outer thread 

cooperating with the inner thread, one of the two 

flanks of the outer thread facing the one end of 

the holding portion and the other of the two flanks 

of the outer thread facing away from the one end 

of the holding portion; and

wherein the inner thread comprises two 

flanks, one of the two flanks of the inner thread 

facing the one end of the holding portion and the 

other of the two flanks of the inner thread facing 

away from the one end of the holding portion, 

each of the two flanks of the inner thread enclosing an angle of 90° with a central axis (M) of the 

holding portion; 

wherein a crest of the outer thread of the locking element is spaced from a root of the inner 

thread when the locking element is tightened such 

that an axial force acts on the holding device to 

prevent the legs from splaying.

Decision on Appeal, at *1. 

B. The Examiner’s Rejection

The examiner rejected claims 32, 33, 35–37, 39, and 

48 of the ’057 Application as being unpatentable over U.S. 

Patents No. 5,005,562 (“Cotrel”) and No. 4,846,614 
IN RE LUTZ BIEDERMANN 5

(“Steinbock”) further in view of U.S. Patent No. 4,688,832 

(“Ortloff”) under 35 U.S.C. § 103(a).

Cotrel discloses a bone screw with a shank (1), a holding portion with internally threaded legs, and a locking 

element or screw (8) to hold a rod (3), as generally shown 

in Figure 3, reproduced below. Cotrel col. 2 ll. 14–34, col. 

3 ll. 4–38. 

Steinbock discloses a machining arrangement for 

moving heavy loads. In that context, it describes different 

thread configurations as follows:

[C]ertain threads are used to repeatedly move or 

translate machine parts against heavy loads. For 

these so-called translation threads a more efficient thread form is required. The most widely 

used thread forms for this purpose are the Square, 

the Acme and the Buttress. The Square thread is 

generally regarded as most efficient, but is diffi-
6 IN RE LUTZ BIEDERMANN

cult to cut because the thread form provides parallel sides. It also cannot be adjusted to compensate 

for wear. The Acme form of thread does not suffer 

from the disadvantages of the Square thread form; 

it is stronger and only slightly less efficient. The 

Bustress [sic] thread form is used for translation 

of loads in one direction only. Because of its nonsymmetrical form, it combines the high efficiency

of the Square thread . . . with the ease of cutting 

and adjustment of the Acme thread. 

Steinbock col. 1 ll. 25–41 (emphasis added). 

Completing the rejection, the examiner relied on the 

Ortloff reference for its disclosure of gaps or clearances 

between the crest of the outer thread and the root of the 

inner thread. The examiner also noted that this feature

would be inherent in a device combining Cotrel and 

Steinbock. 

The examiner considered Cotrel to disclose all elements of the claimed invention except for the orientation 

of the two flanks of the inner thread enclosing an angle of 

90° with respect to the central axis of the holding portion. 

As for the missing thread configuration, the examiner 

relied on Steinbock, stating: 

It is noted that there are a limited number of 

thread profile choices available to a person of ordinary skill in the art for providing a threaded 

connection. In this regard it is noted that Steinbock teaches different types of threads with a 

square thread being the most efficient for load 

transfer (col. 1, lines 14–44). 

Therefore, it would have been obvious to one 

of ordinary skill in the art at the time the invention was made to have provided threads with a 
IN RE LUTZ BIEDERMANN 7

square profile on the Cotrel legs, as taught by 

Steinbock, for efficient load transfer. 

Office Action at 2–3, Application No. 10/306,057 (Dec. 29, 

2008) (“Final Rejection”) (emphasis added); accord Examiner’s Answer at 3, Ex parte Biedermann, No. 2010-

006113, Application No. 10/306,057 (B.P.A.I. May 30, 

2012) (Decision on Appeal) (“Examiner’s Answer”). 

C. The Board’s Decisions

In analyzing the propriety of the examiner’s rejection, 

the Board discussed the threads shown in Cotrel and 

Steinbock and also made reference, for the first time, to 

Erik Oberg et al., Machinery’s Handbook (Christopher J. 

McCauley et al. eds., 26th ed. 2000) (“Machinery’s Handbook”). The Board did not reach Ortloff and instead relied 

on the examiner’s alternative inherency rationale with 

respect to the gap. 

With regards to the threads, Cotrel says,

The female thread of the two flanks or branches of 

the body of the implant and the thread of the plug 

can be made with a saw-tooth pitch, in order to 

avoid the spreading of the two flanks by completely eliminating the radial component of the load on 

screwing up.

Cotrel col. 2 ll. 54–58 (emphasis added) (reference numbers omitted). The Machinery’s Handbook at 1817 indicates that a saw-tooth thread is a buttress thread. See 

Decision on Appeal, at *2 & n.3. 

The Board specifically found that

[t]he fact that Steinbock groups square, Acme, 

and buttress threadforms would at least suggest 
8 IN RE LUTZ BIEDERMANN

their interchangeability. . . . Cotrel already recognized the desirability of eliminating the radial 

component of the load on screwing and the suitability of a threadform, the saw-tooth or buttress 

form, that may have typically been used for translational applications to do so. Thus, one of ordinary skill in the art would have a reasonable 

expectation that a square threadform, which, like

the buttress thread is also typically used for axial 

translation, would function in a manner similar to 

a saw-tooth or buttress thread to eliminate the

radial component of a load on screwing, thereby 

discouraging spreading of Cotrel’s flanks . . . , or 

splaying. 

The Examiner’s discussion as to the benefits 

that would be realized by Cotrel from improved efficiency is limited. However, this characteristic 

appears to be just one of several factors, including 

machinability, that one of ordinary skill in the art 

would consider when selecting an appropriate 

threadform. . . . Though not referred to as a sawtooth thread, [another reference], discussed in

[Biedermann’s] Specification, appears to have 

similar characteristics to a saw-tooth and, according to [Biedermann], is difficult to produce—a 

problem [Biedermann] perceive[s] as mitigated by 

use of a square thread. 

Id. at *2 (footnotes omitted) (citations omitted) (internal 

quotation marks omitted). The Board thus affirmed the 

examiner’s rejection. 

Biedermann requested rehearing, arguing that the 

Board issued a new ground of rejection by relying on 

“interchangeability” instead of “efficiency” and by referring to the Machinery’s Handbook, and additionally 

arguing that the Board failed to consider the negative 
IN RE LUTZ BIEDERMANN 9

teachings of Steinbock that relate to machinability. The 

Board denied Biedermann’s request. The Board explained that “by ‘interchangability’ [sic] we meant that 

the record demonstrates a likelihood that the threadforms 

grouped by Steinbock could successfully be substituted 

into Cotrel’s device. . . . Cotrel clearly expresses the 

desirability of minimizing or eliminating the radial component of load on screwing up.” Decision on Rehearing, at 

*1. The Board further explained that “Steinbock’s grouping was regarded as a suggestion that, in addition to a 

saw-tooth or buttress thread, good results may also be 

achieved using an Acme or Square thread which share 

certain characteristics that Cotrel recognized as important—the ability to eliminate or minimize radial 

loading.” Id. at *2. The Board acknowledged that “[t]he

Examiner may have specifically proposed in the Office 

Action to select a thread ‘for the most efficient load transfer’ as opposed to one that minimized or eliminated radial 

loading due to contact or interference.” Id. at *1 (emphasis added). 

As to the Machinery’s Handbook, the Board found 

that “[t]he only fact detrimental to [Biedermann] based 

upon this extrinsic evidence was confirming that the ‘sawtooth’ and ‘buttress’ threading described by Cotrel and 

Steinbock, respectively, referred to essentially the same 

thing,” of which Biedermann was “already aware.” Id. 

The Board asserted that it did not change the thrust of 

the rejection and instead “merely relied upon a reference 

akin to a technical dictionary to confirm the meaning of 

terms used in the references before us.” Id. 

Commenting on machinability, the Board noted that

the square thread was beneficial, but that its “drawback, 

according to Steinbock, is difficulty cutting. The record, 

when considered as a whole, does not support [Biedermann’s] position that difficulty cutting square threads
10 IN RE LUTZ BIEDERMANN

would lead one away from their use if one desired . . . 

[their] benefit.” Id. at *2. 

The Board denied reconsideration and again affirmed 

the examiner’s rejection. Biedermann appeals. This court 

has jurisdiction under 28 U.S.C. § 1295(a)(4)(A). 

II. DISCUSSION

A. Standard of Review

“Whether the Board relied on a new ground of rejection is a legal question that we review de novo.” In re 

Stepan Co., 660 F.3d 1341, 1343 (Fed. Cir. 2011). 

B. Analysis

“Obviousness is a question of law based on underlying 

findings of fact.” In re Kubin, 561 F.3d 1351, 1355 (Fed. 

Cir. 2009). The underlying factual inquiries are: (1) “‘the 

scope and content of the prior art,’” (2) the “‘differences 

between the prior art and the claims at issue,’” (3) “‘the 

level of ordinary skill in the pertinent art,’” and (4) “‘secondary considerations’” of nonobviousness. KSR Int’l Co. 

v. Teleflex Inc., 550 U.S. 398, 406 (2007) (quoting Graham 

v. John Deere Co. of Kan. City, 383 U.S. 1, 17–18 (1966)). 

In assessing the obviousness of patent claims, 

[o]ften, it will be necessary for a court to look to 

interrelated teachings of multiple patents . . . in 

order to determine whether there was an apparent reason to combine the known elements in the 

fashion claimed by the patent at issue. To facilitate review, this analysis should be made explicit. 

See In re Kahn, 441 F. 3d 977, 988 (CA Fed. 2006) 

(“[R]ejections on obviousness grounds cannot be 

sustained by mere conclusory statements; instead, 

there must be some articulated reasoning with 
IN RE LUTZ BIEDERMANN 11

some rational underpinning to support the legal 

conclusion of obviousness”). 

KSR, 550 U.S. at 418 (alteration in internal quotation in 

original). The articulated reasoning and factual underpinnings of an examiner’s rejection are, thus, essential 

elements of any stated ground of rejection to which applicants are entitled to notice and a fair opportunity to 

respond.

 The central question in the present case is whether 

the Board and the examiner properly relied on the same 

articulated reasoning and factual underpinnings in rejecting Biedermann’s claims or whether the Board made new 

findings and adopted different reasons to support a new 

ground of rejection, thus depriving Biedermann of both 

notice and an opportunity to respond.

Biedermann argues that the Board did not rely on the 

examiner’s efficient load transfer rationale to combine 

Cotrel and Steinbock, and instead issued a new ground of 

rejection by adopting a rationale based on newly found 

facts relating to the avoidance of splaying. Biedermann 

argues that the examiner did not find facts about Cotrel’s 

threads or splaying and that the Board found the threadform of Cotrel interchangeable with the square threadform based on the new findings that: (a) Steinbock 

grouped square and buttress threads; (b) the Machinery’s 

Handbook associated saw-tooth and buttress threads; (c)

Cotrel’s threads were saw-tooth threads that avoid splaying; and (d) square threads would similarly avoid splaying. Biedermann also argues that the Board was critical 

of the examiner’s rationale and relied on the Machinery’s 

Handbook in finding a new reason to combine Cotrel and 

Steinbock. Moreover, Biedermann argues that the mere

fact that the Board was responding to Biedermann’s 

arguments does not obviate the fact that the Board issued 

a new ground of rejection. Finally, Biedermann argues 
12 IN RE LUTZ BIEDERMANN

that the Board newly and erroneously concluded that one 

of ordinary skill would have reason to substitute square 

threads for the saw-tooth threads in Cotrel because they 

are easier to machine. 

 The government argues that the Board did not issue a 

new ground of rejection, that Biedermann had the opportunity to respond to the thrust of the rejection, and that 

the Board relied on the examiner’s efficient load transfer 

rationale and simply provided a more detailed explanation. The government also argues that the Board did not 

find new facts regarding Cotrel’s thread type, its effect on 

splaying, or its relationship or similarity to other thread 

types because the Board was responding to or relying on 

Biedermann’s arguments or statements. The government 

also argues that the Board only used the Machinery’s 

Handbook as a technical dictionary. Finally, the government argues that the Board did not change the thrust of 

the rejection by referring to machinability because it was 

listing additional benefits in response to one of Biedermann’s arguments. 

The Patent and Trademark Office (“PTO”) is subject 

to the Administrative Procedure Act (“APA”). See Dickinson v. Zurko, 527 U.S. 150, 154 (1999). Under the APA, 

the PTO “must assure that an applicant’s petition is fully 

and fairly treated at the administrative level.” In re 

Kumar, 418 F.3d 1361, 1367 (Fed. Cir. 2005). The APA 

requires the PTO “to provide prior notice to the applicant 

of all ‘matters of fact and law asserted’ prior to an appeal 

hearing before the Board.” Stepan, 660 F.3d at 1345

(quoting 5 U.S.C. § 554(b)(3)); see also In re Leithem, 661 

F.3d 1316, 1319 (Fed. Cir. 2011) (“Under the [APA], an

applicant for a patent who appeals a rejection to the 

Board is entitled to notice of the factual and legal bases 

upon which the rejection was based.” (citing 5 U.S.C. 

§ 554(b)(3))). Accordingly, the PTO’s rules “provide that 

when the Board relies upon a new ground of rejection not 
IN RE LUTZ BIEDERMANN 13

relied upon by the examiner, the applicant is entitled to 

reopen prosecution or to request a rehearing.” Leithem, 

661 F.3d at 1319 (citing 37 C.F.R. § 41.50(b)). These

rights “ensure that the Board can fulfill its notice obligation to the applicant during prosecution.” Stepan, 660 

F.3d at 1344. Failure to follow these procedures requires

this court to vacate the Board’s decision. See Rambus Inc.

v. Rea, __ F.3d __, No. 2012-1634, 2013 WL 5312505, at *7 

(Fed. Cir. Sept. 24, 2013).

When considering whether the Board issued a new 

ground of rejection, the “ultimate criterion of whether a 

rejection is considered ‘new’ in a decision by the Board is 

whether applicants have had fair opportunity to react to

the thrust of the rejection.” Leithem, 661 F.3d at 1319 

(internal quotation marks and alteration marks omitted). 

While “[t]he Board need not recite and agree with the 

examiner’s rejection in haec verba to avoid issuing a new 

ground of rejection,” 

[m]ere reliance on the same statutory basis and 

the same prior art references, alone, is insufficient 

to avoid making a new ground of rejection when 

the Board relies on new facts and rationales not 

previously raised to the applicant by the examiner. This court’s predecessor long acknowledged 

the right of the Board to make additional findings 

of fact based upon the Board’s own knowledge and 

experience to fill in the gaps that might exist in 

the examiner’s evidentiary showing. But the 

Board’s power to do so is construed narrowly and 

when reliance upon such facts changes the thrust 

of the rejection, the Board’s action does everything

but cry out for an opportunity to respond. 

Id. (citations omitted) (internal quotation marks omitted). 

A new ground of rejection, however, generally will not be 

found based on the Board “further explain[ing] the exam-
14 IN RE LUTZ BIEDERMANN

iner’s rejection” or the Board’s thoroughness in responding to an applicant’s argument. See In re Jung, 637 F.3d 

1356, 1364–65 (Fed. Cir. 2011). 

In Leithem, this court concluded that the Board issued

a new ground of rejection. See 661 F.3d at 1317. The

patent claim at issue in Leithem covered a diaper containing wood “fluff pulp” prepared by a certain method. Id. 

The examiner rejected the claim as obvious over a combination including the “Novak” reference, which the examiner explained disclosed “a method of making fluff pulp.” 

Id. (internal quotation marks omitted). Leithem argued 

and the Board “agreed” that Novak “d[id] not disclose a 

fluffed pulp,” but the Board sustained the examiner’s 

rejection and found that Novak disclosed “a pulp which 

may be fluffed.” Id. at 1317–18 (internal quotation marks 

omitted). This court concluded that “[t]he thrust of the 

Board’s rejection changes when, as here, it finds facts not 

found by the examiner regarding the differences between

the prior art and the claimed invention, and these facts 

are the principal evidence upon which the Board’s rejection was based.” Id. at 1320 (citation omitted).

Here, the examiner’s reasoning in support of combining the square thread of Steinbock with the device of 

Cotrel was that there were a limited number of threads 

that could be used and that a square thread was the most 

efficient. While the examiner in the Examiner’s Answer 

made a passing reference to splaying in relation to the 

gaps between the inner and outer threads, the examiner’s 

rejection neither relied upon nor even noted the avoidance 

of splaying as a factor. The Board, on the other hand, 

found new facts as the basis for concluding that the 

combination of Cotrel and Steinbock would have been 

obvious: that Cotrel teaches avoiding splaying with sawtooth threads; that saw-tooth threads are buttress 

threads; that Steinbock groups together the square 

threads and buttress threads; and that square threads 
IN RE LUTZ BIEDERMANN 15

avoid splaying. The principal reason the examiner combined the references was the efficiency of a square thread. 

The principal reason the Board affirmed the combination 

of the references was the avoidance of splaying by using 

square threads. These are different grounds and form the 

bases or underpinnings of different rejections. Even the 

Board itself recognized that efficiency and avoiding splaying were different. Decision on Rehearing, at *1. This is 

analogous to Leithem in which the Board distinguished

fluffed pulp from pulp that could be fluffed. See 661 F.3d 

at 1318, 1320. 

The government’s argument that the Board was 

providing additional details for the examiner’s reasoning, 

rather than changing the thrust of the rejection, is not 

persuasive. The thrust of the rejection changed when the 

Board found a new factual basis for the reason to combine. The Board went beyond filling in gaps in the examiner’s reasoning because it is not clear that the examiner’s 

reasoning survived in the Board’s rejection. Unlike Jung, 

there is no indication that the Board was merely explaining the examiner’s rejection. See 637 F.3d at 1365. The 

present case is similar to Rambus, 2013 WL 5312505, at 

*7, in which the examiner made an erroneous finding in 

support of a combination of references and the Board 

made new, alternative findings to support the combination. “While the Board’s findings may ultimately be 

correct, we will not affirm a Board rejection, like this one, 

which essentially provides a new motivation to combine 

the references.” Id.

The government asserts that the Board was merely 

responding to Biedermann’s arguments rather than 

issuing a new ground of rejection. A new ground of rejection is not negated by the fact that the Board is responding to an appellant’s argument. See Stepan, 660 F.3d at

1345 (“[T]he mere fortuity that Stepan addressed the 

validity of the Declaration on its own, without the issue 
16 IN RE LUTZ BIEDERMANN

being raised by the examiner, does not permit the Board 

to reject the Declaration as ineffective without designating its decision as a new ground of rejection.”); Leithem, 

661 F.3d at 1317, 1320 (concluding that the Board issued 

a new ground of rejection despite the fact that the Board 

“agreed with Leithem” that Novak did not teach a fluffed 

pulp). 

As to the Machinery’s Handbook, the citation of a new 

reference will be a new ground of rejection in some instances:

Ordinarily, citation by the board of a new reference, such as the dictionary in this case, and reliance thereon to support a rejection, will be 

considered as tantamount to the assertion of a 

new ground of rejection. This will not be the case, 

however, where such a reference is a standard 

work, cited only to support a fact judicially noticed 

and . . . the fact so noticed plays a minor role, 

serving only to fill in the gaps which might exist 

in the evidentiary showing made by the Examiner 

to support a particular ground for rejection.

In re Boon, 439 F.2d 724, 727-28 (CCPA 1971) (citation 

omitted) (internal quotation marks omitted). 

In this case, the Board used the Machinery’s Handbook to associate buttress and saw-tooth threads. There 

is no clear gap in the examiner’s reasoning that would be 

filled by the association between saw-tooth and buttress 

threads, particularly since Cotrel’s threads appear irrelevant to the examiner’s reasoning. Rather, the association 

between saw-tooth and buttress threads played an important role, not a minor role, in the Board’s new reasoning by providing the link to associate Cotrel’s threads 

with one of the threadforms grouped in Steinbock. The 
IN RE LUTZ BIEDERMANN 17

Machinery’s Handbook, thus, was used as part of the new 

ground of rejection.

The Board’s treatment of machinability in the Decision on Appeal was also a new ground of rejection. The 

Board treated machinability as another factor, in addition 

to efficiency, that one of ordinary skill would consider in 

selecting a threadform, making it part of the reason to 

combine the references. See Decision on Appeal, at *2. 

Identifying machinability as an additional reason to 

combine does not mean that it is not a new ground of 

rejection. See In re Waymouth, 486 F.2d 1058, 1061 

(CCPA 1973) (“To attempt to deny appellants an opportunity to provide a different and appropriate response to 

the board’s rejection by saying that the board merely 

advanced ‘an additional reason’ for affirming the examiner begs the question and does not satisfy the administrative due process . . . .”), modified, 489 F.2d 1297 (CCPA

1974). There is no apparent connection between machinability and the examiner’s reason to combine based on 

efficiency. 

III. CONCLUSION

For the foregoing reasons, this court vacates the 

Board’s decision and remands for further proceedings.

VACATED AND REMANDED